kolibrios/kernel/trunk/docs/sysfuncs.txt

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;                                                              ;;
;; Copyright (C) KolibriOS team 2004-2012. All rights reserved. ;;
;; Distributed under terms of the GNU General Public License    ;;
;;                                                              ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

SYSTEM FUNCTIONS of OS Kolibri 0.7.7.0

Number of the function is located in the register eax.
The call of the system function is executed by "int 0x40" command.
All registers except explicitly declared in the returned value,
    including eflags, are preserved.


======================================================================
============== Function 0 - define and draw the window. ==============
======================================================================
Defines an application window. Draws a frame of the window, header and
working area. For skinned windows defines standard close and minimize
buttons.
Parameters:
  * eax = 0 - function number
  * ebx = [coordinate on axis x]*65536 + [size on axis x]
  * ecx = [coordinate on axis y]*65536 + [size on axis y]
  * edx = 0xXYRRGGBB, where:
    * Y = style of the window:
      * Y=0 - type I - fixed-size window
      * Y=1 - only define window area, draw nothing
      * Y=2 - type II - variable-size window
      * Y=3 - skinned window
      * Y=4 - skinned fixed-size window
      * other possible values (from 5 up to 15) are reserved,
        function call with such Y is ignored
    * RR, GG, BB = accordingly red, green, blue components of a color
      of the working area of the window (are ignored for style Y=1)
    * X = DCBA (bits)
      * A = 1 - window has caption; for styles Y=3,4 caption string
                  must be passed in edi, for other styles use
                  subfunction 1 of function 71
      * B = 1 - coordinates of all graphics primitives are relative to
                  window client area
      * C = 1 - don't fill working area on window draw
      * D = 0 - normal filling of the working area, 1 - gradient
    The following parameters are intended for windows
    of a type I and II, and ignored for styles Y=1,3:
  * esi = 0xXYRRGGBB - color of the header
    * RR, GG, BB define color
    * Y=0 - usual window, Y=1 - unmovable window (works for all window styles)
    * X defines a gradient of header: X=0 - no gradient,
      X=8 - usual gradient,
      for windows of a type II X=4 - negative gradient
    * other values of X and Y are reserved
  * edi = 0x00RRGGBB - color of the frame
Returned value:
  * function does not return value
Remarks:
  * Position and sizes of the window are installed by the first
    call of this function and are ignored at subsequent; to change
    position and/or sizes of already created window use function 67.
  * For windows with styles Y=3,4 and caption (A=1) caption string
    is set by the first call of this function and is ignored
    at subsequent (strictly speaking, is ignored after a call to
    subfunction 2 of function 12 - end redraw); to change caption of
    already created window use subfunction 1 of function 71.
  * If the window has appropriate styles, position and/or sizes can be
    changed by user. Current position and sizes can be obtained
    by function 9.
  * The window must fit on the screen. If the transferred
    coordinates and sizes do not satisfy to this condition,
    appropriate coordinate (or, probably, both) is considered as zero,
    and if it does not help too, the appropriate size
    (or, probably, both) is installed in a size of the screen.

    Further let us designate xpos,ypos,xsize,ysize - values passed
    in ebx,ecx. The coordinates are resulted concerning
    the left upper corner of the window, which, thus, is set as (0,0),
    coordinates of the right lower corner essence (xsize,ysize).
  * The sizes of the window are understood in sence of coordinates
    of the right lower corner. This concerns all other functions too.
    It means, that the real sizes are on 1 pixel more.
  * The window of type I looks as follows:
    * draw external frame of color indicated in edi, 1 pixel in width
    * draw header - rectangle with the left upper corner (1,1) and
      right lower (xsize-1,min(20,ysize-1)) color indicated in esi
      (taking a gradient into account)
    * if ysize>21, fill the working area of the window -
      rectangle with the left upper corner (1,21) and right lower
      (xsize-1,ysize-1) (sizes (xsize-1)*(ysize-21)) with color
      indicated in edx (taking a gradient into account)
    * if A=1 and caption has been already set by subfunction 1
      of function 71, it is drawn in the corresponding place of header
  * The window of style Y=1 looks as follows:
    * completely defined by the application
  * The window of type II looks as follows:
    * draw external frame of width 1 pixel with the "shaded" color
      edi (all components of the color decrease twice)
    * draw intermediate frame of width 3 pixels with color edi
    * draw internal frame of width 1 pixel with the "shaded" color edi
    * draw header - rectangle with the left upper corner (4,4)
      and right lower (xsize-4,min(20,ysize)) color, indicated in esi
      (taking a gradient into account)
    * if ysize>=26, fill the working area of the window -
      rectangle with the left upper corner (5,20) and right lower
      (xsize-5,ysize-5) with color indicated in edx
      (taking a gradient into account)
    * if A=1 and caption has been already set by subfunction 1
      of function 71, it is drawn in the corresponding place of header
  * The skinned window looks as follows:
    * draw external frame of width 1 pixel
      with color 'outer' from the skin
    * draw intermediate frame of width 3 pixel
      with color 'frame' from the skin
    * draw internal frame of width 1 pixel
      with color 'inner' from the skin
    * draw header (on bitmaps from the skin) in a rectangle
      (0,0) - (xsize,_skinh-1)
    * if ysize>=26, fill the working area of the window -
      rectangle with the left upper corner (5,_skinh) and right lower
      (xsize-5,ysize-5) with color indicated in edx
      (taking a gradient into account)
    * define two standard buttons: close and minimize
      (see function 8)
    * if A=1 and edi contains (nonzero) pointer to caption string,
      it is drawn in place in header defined in the skin
    * value _skinh is accessible as the result of call
      subfunction 4 of function 48

---------------------- Constants for registers: ----------------------
  eax - SF_CREATE_WINDOW (0)
======================================================================
================ Function 1 - put pixel in the window. ===============
======================================================================
Parameters:
  * eax = 1 - function number
  * ebx = x-coordinate (relative to the window)
  * ecx = y-coordinate (relative to the window)
  * edx = 0x00RRGGBB - color of a pixel
    edx = 0x01xxxxxx - invert color of a pixel
          (low 24 bits are ignored)
Returned value:
  * function does not return value

---------------------- Constants for registers: ----------------------
  eax - SF_PUT_PIXEL (1)
======================================================================
============ Function 2 - get the code of the pressed key. ===========
======================================================================
Takes away the code of the pressed key from the buffer.
Parameters:
  * eax = 2 - function number
Returned value:
  * if the buffer is empty, function returns eax=1
  * if the buffer is not empty, function returns al=0,
    ah=code of the pressed key,
    bits 16-23 = contain scancode for pressed key in ASCII mode,
                 in the scancodes mode this bits cleared.
    bits 23-31 = zero
  * if there is "hotkey", function returns al=2,
    ah=scancode of the pressed key (0 for control keys),
    high word of eax contains a status of control keys at the moment
    of pressing a hotkey
Remarks:
  * There is a common system buffer of the pressed keys
    by a size of 120 bytes, organized as queue.
  * There is one more common system buffer on 120 "hotkeys".
  * If the application with the inactive window calls this function,
    the buffer of the pressed keys is considered to be empty.
  * By default this function returns ASCII-codes; to switch
    to the scancodes mode (and back) use function 66.
    However, hotkeys are always notificated as scancodes.
  * To find out, what keys correspond to what codes, start
    the application keyascii and scancode.
  * Scancodes come directly from keyboard and are fixed;
    ASCII-codes turn out with usage of the conversion tables,
    which can be set by subfunction 2 of function 21
    and get by subfunction 2 of function 26.
  * As a consequence, ASCII-codes take into account current
    keyboard layout (rus/en) as opposed to scancodes.
  * This function notifies only about those hotkeys, which were
    defined by this thread by subfunction 4 of function 66.

---------------------- Constants for registers: ----------------------
  eax - SF_GET_KEY (2)
======================================================================
==================== Function 3 - get system time. ===================
======================================================================
Parameters:
  * eax = 3 - function number
Returned value:
  * eax = 0x00SSMMHH, where HH:MM:SS = Hours:Minutes:Seconds
  * each item is BCD-number, for example,
    for time 23:59:59 function returns 0x00595923
Remarks:
  * See also subfunction 9 of function 26 - get time from
    the moment of start of the system; it is more convenient, because
    returns simply DWORD-value of the time counter.
  * System time can be set by function 22.

---------------------- Constants for registers: ----------------------
  eax - SF_GET_SYS_TIME (3)
======================================================================
=================== Function 4 - draw text string. ===================
======================================================================
Parameters:
  * eax = 4 - function number
  * ebx = X*65536+Y, coordinates in the window or buffer
  * ecx = 0xXXRRGGBB, where
    * RR, GG, BB specify text color
    * XX = ABFFCSSS (bits):
      * A=1 - output zero terminated string
      * B=1 - fill background (color = edi)
      * FF specifies the font and encoding:
        0 = 6x9  cp866
        1 = 8x16 cp866
        2 = 8x16 UTF-16LE
        3 = 8x16 UTF-8
      * C=0 - draw to the window,
        C=1 - draw to the user buffer (edi)
      * SSS = (size multiplier)-1, so 0 = x1, 7 = x8
  * edx = pointer to the beginning of the string
  * esi = for A=0 length of the string, for A=1 is ignored
  * edi = for B=1 color to fill background,
          for C=1 pointer to user buffer

Returned value:
  * function does not return value
Remarks:
  * You can not use B=1 and C=1 at the same time, since both use edi.
  * When SSS=0, font may be smoothed, depending on system setting.
  * User buffer structure:
Xsize       dd
Ysize       dd
picture     rb  Xsize*Ysize*4  ; 32 bpp

---------------------- Constants for registers: ----------------------
  eax - SF_DRAW_TEXT (4)
======================================================================
========================= Function 5 - delay. ========================
======================================================================
Delays execution of the program on the given time.
Parameters:
  * eax = 5 - function number
  * ebx = time in the 1/100 of second
Returned value:
  * function does not return value
Remarks:
  * Passing ebx=0 does not transfer control to the next process
    and does not make any operations at all. If it is really required
    to transfer control to the next process (to complete a current
    time slice), use subfunction 1 of function 68.

---------------------- Constants for registers: ----------------------
  eax - SF_SLEEP (5)
======================================================================
=============== Function 7 - draw image in the window. ===============
======================================================================
Paramters:
  * eax = 7 - function number
  * ebx = pointer to the image in the format BBGGRRBBGGRR...
  * ecx = [size on axis x]*65536 + [size on axis y]
  * edx = [coordinate on axis x]*65536 + [coordinate on axis y]
Returned value:
  * function does not return value
Remarks:
  * Coordinates of the image are coordinates of the upper left corner
    of the image relative to the window.
  * Size of the image in bytes is 3*xsize*ysize.

---------------------- Constants for registers: ----------------------
  eax - SF_PUT_IMAGE (7)
======================================================================
=============== Function 8 - define/delete the button. ===============
======================================================================
Parameters for button definition:
  * eax = 8 - function number
  * ebx = [coordinate on axis x]*65536 + [size on axis x]
  * ecx = [coordinate on axis y]*65536 + [size on axis y]
  * edx = 0xXYnnnnnn, where:
    * nnnnnn = identifier of the button
    * high (31st) bit of edx is cleared
    * if 30th bit of edx is set - do not draw the button
    * if 29th bit of edx is set - do not draw a frame
      at pressing the button
  * esi = 0x00RRGGBB - color of the button
Parameters for button deleting:
  * eax = 8 - function number
  * edx = 0x80nnnnnn, where nnnnnn - identifier of the button
Returned value:
  * function does not return value
Remarks:
  * Sizes of the button must be more than 0 and less than 0x8000.
  * For skinned windows definition of the window
    (call of 0th function) creates two standard buttons -
    for close of the window with identifier 1 and
    for minimize of the window with identifier 0xffff.
  * The creation of two buttons with same identifiers is admitted.
  * The button with the identifier 0xffff at pressing is interpreted
    by the system as the button of minimization, the system handles
    such pressing independently, not accessing to the application.
    In rest it is usual button.
  * Total number of buttons for all applications is limited to 4095.

---------------------- Constants for registers: ----------------------
  eax - SF_DEFINE_BUTTON (8)
======================================================================
============ Function 9 - information on execution thread. ===========
======================================================================
Parameters:
  * eax = 9 - function number
  * ebx = pointer to 1-Kb buffer
  * ecx = number of the slot of the thread
    ecx = -1 - get information on the current thread
Returned value:
  * eax = maximum number of the slot of a thread
  * buffer pointed to by ebx contains the following information:
    * +0: dword: usage of the processor (how many time units
      per second leaves on execution of this thread)
    * +4: word: position of the window of thread in the window stack
    * +6: word: (has no relation to the specified thread)
      number of the thread slot, which window has in the window stack
      position ecx
    * +8: word: reserved
    * +10 = +0xA: 11 bytes: name of the process
      (name of the started file - executable file without extension)
    * +21 = +0x15: byte: reserved, this byte is not changed
    * +22 = +0x16: dword: address of the process in memory
    * +26 = +0x1A: dword: size of used memory - 1
    * +30 = +0x1E: dword: identifier (PID/TID)
    * +34 = +0x22: dword: coordinate of the thread window on axis x
    * +38 = +0x26: dword: coordinate of the thread window on axis y
    * +42 = +0x2A: dword: size of the thread window on axis x
    * +46 = +0x2E: dword: size of the thread window on axis y
    * +50 = +0x32: word: status of the thread slot:
      * 0 = thread is running
      * 1 = thread is suspended
      * 2 = thread is suspended while waiting for event
      * 3 = thread is terminating as a result of call to function -1
        or under duress as a result of call to subfunction 2
        of function 18 or termination of the system
      * 4 = thread is terminating as a result of exception
      * 5 = thread waits for event
      * 9 = requested slot is free, all other information on the slot
        is not meaningful
    * +52 = +0x34: word: reserved, this word is not changed
    * +54 = +0x36: dword: coordinate of the client area on axis x
    * +58 = +0x3A: dword: coordinate of the client area on axis y
    * +62 = +0x3E: dword: width of the client area
    * +66 = +0x42: dword: height of the client area
    * +70 = +0x46: byte: state of the window - bitfield
      * bit 0 (mask 1): window is maximized
      * bit 1 (mask 2): window is minimized to panel
      * bit 2 (mask 4): window is rolled up
    * +71 = +0x47: dword: event mask
    * +75 = +0x4B: byte: keyboard mode(ASCII = 0; SCAN = 1)
Remarks:
  * Slots are numbered starting from 1.
  * Returned value is not a total number of threads, because there
    can be free slots.
  * When process is starting, system automatically creates
    execution thread.
  * Function gives information on the thread. Each process has
    at least one thread. One process can create many threads,
    in this case each thread has its own slot and the fields
    +10, +22, +26 in these slots coincide.
    Applications have no common way to define whether two threads
    belong to one process.
  * The active window - window on top of the window stack -
    receives the messages on a keyboard input. For such window
    the position in the window stack coincides with returned value.
  * Slot 1 corresponds to special system thread, for which:
    * the window is in the bottom of the window stack, the fields
      +4 and +6 contain value 1
    * name of the process - "OS/IDLE" (supplemented by spaces)
    * address of the process in memory is 0, size of used memory is
      16 Mb (0x1000000)
    * PID=1
    * coordinates and sizes of the window and the client area are by
      convention set to 0
    * status of the slot is always 0 (running)
    * the execution time adds of time leaving on operations itself
      and idle time in waiting for interrupt (which can be got by call
      to subfunction 4 of function 18).
  * Beginning from slot 2, the normal applications are placed.
  * The normal applications are placed in memory at the address
    0 (kernel constant 'std_application_base_address').
    There is no intersection, as each process has its own page table.
  * At creation of the thread it is assigned the slot
    in the system table and identifier (Process/Thread IDentifier =
    PID/TID), which do not vary with time for given thread.
    After completion of the thread its slot can be anew used
    for another thread. The thread identifier can not be assigned
    to other thread even after completion of this thread.
    Identifiers, assigned to new threads, grow monotonously.
  * If the thread has not yet defined the window by call to
    function 0, the position and the sizes
    of its window are considered to be zero.
  * Coordinates of the client area are relative to the window.
  * At the moment only the part of the buffer by a size
    76 = 0x4C bytes is used. Nevertheless it is recommended to use
    1-Kb buffer for the future compatibility, in the future
    some fields can be added.

---------------------- Constants for registers: ----------------------
  eax - SF_THREAD_INFO (9)
======================================================================
==================== Function 10 - wait for event. ===================
======================================================================
If the message queue is empty, waits for appearance of the message
in queue. In this state thread does not consume CPU time.
Then reads out the message from queue.

Parameters:
  * eax = 10 - function number
Returned value:
  * eax = event (see the list of events)
Remarks:
  * Those events are taken into account only which enter into
    a mask set by function 40. By default it is
    redraw, key and button events.
  * To check, whether there is a message in queue, use function 11.
    To wait for no more than given time, use function 23.

---------------------- Constants for registers: ----------------------
  eax - SF_WAIT_EVENT (10)
======================================================================
=============== Function 11 - check for event, no wait. ==============
======================================================================
If the message queue contains event, function reads out
and return it. If the queue is empty, function returns 0.
Parameters:
  * eax = 11 - function number
Returned value:
  * eax = 0 - message queue is empty
  * else eax = event (see the list of events)
Remarks:
  * Those events are taken into account only, which enter into
    a mask set by function 40. By default it is
    redraw, key and button events.
  * To wait for event, use function 10.
    To wait for no more than given time, use function 23.

---------------------- Constants for registers: ----------------------
  eax - SF_CHECK_EVENT (11)
======================================================================
=============== Function 12 - begin/end window redraw. ===============
======================================================================

---------------- Subfunction 1 - begin window redraw. ----------------
Parameters:
  * eax = 12 - function number
  * ebx = 1 - subfunction number
Returned value:
  * function does not return value

----------------- Subfunction 2 - end window redraw. -----------------
Parameters:
  * eax = 12 - function number
  * ebx = 2 - subfunction number
Returned value:
  * function does not return value
Remarks:
  * Subfunction 1 deletes all buttons defined with
    function 8, they must be defined again.

---------------------- Constants for registers: ----------------------
  eax - SF_REDRAW (12)
  ebx - SSF_BEGIN_DRAW (1), SSF_END_DRAW (2)
======================================================================
============ Function 13 - draw a rectangle in the window. ===========
======================================================================
Parameters:
  * eax = 13 - function number
  * ebx = [coordinate on axis x]*65536 + [size on axis x]
  * ecx = [coordinate on axis y]*65536 + [size on axis y]
  * edx = color 0xRRGGBB or 0x80RRGGBB for gradient fill
Returned value:
  * function does not return value
Remarks:
  * Coordinates are understood as coordinates of the left upper corner
    of a rectangle relative to the window.

---------------------- Constants for registers: ----------------------
  eax - SF_DRAW_RECT (13)
======================================================================
=================== Function 14 - get screen size. ===================
======================================================================
Parameters:
  * eax = 14 - function number
Returned value:
  * eax = [xsize]*65536 + [ysize], where
  * xsize = x-coordinate of the right lower corner of the screen =
            horizontal size - 1
  * ysize = y-coordinate of the right lower corner of the screen =
            vertical size - 1
Remarks:
  * See also subfunction 5 of function 48 - get sizes of
    working area of the screen.

---------------------- Constants for registers: ----------------------
  eax - SF_GET_SCREEN_SIZE (14)
======================================================================
== Function 15, subfunction 1 - set a size of the background image. ==
======================================================================
Parameters:
  * eax = 15 - function number
  * ebx = 1 - subfunction number
  * ecx = width of the image
  * edx = height of the image
Returned value:
  * function does not return value
Remarks:
  * Before calling subfunctions 2 and 5 you should call this function
    to set image size!
  * For update of the screen (after completion of a series of commands
    working with a background) call subfunction 3.
  * There is a pair function for get size of the background image -
    subfunction 1 of function 39.

---------------------- Constants for registers: ----------------------
  eax - SF_BACKGROUND_SET (15)
  ebx - SSF_SIZE_BG (1)
======================================================================
=== Function 15, subfunction 2 - put pixel on the background image. ==
======================================================================
Parameters:
  * eax = 15 - function number
  * ebx = 2 - subfunction number
  * ecx = offset
  * edx = color of a pixel 0xRRGGBB
Returned value:
  * function does not return value
Remarks:
  * Offset for a pixel with coordinates (x,y) is calculated as
    (x+y*xsize)*3.
  * If the given offset exceeds size set by subfunction 1,
    the call is ignored.
  * For update of the screen (after completion of a series of commands
    working with a background) call subfunction 3.
  * There is a pair function for get pixel on the background image -
    subfunction 2 of function 39.

---------------------- Constants for registers: ----------------------
  eax - SF_BACKGROUND_SET (15)
  ebx - SSF_PIXEL_BG (2)
======================================================================
=========== Function 15, subfunction 3 - redraw background. ==========
======================================================================
Parameters:
  * eax = 15 - function number
  * ebx = 3 - subfunction number
Returned value:
  * function does not return value

---------------------- Constants for registers: ----------------------
  eax - SF_BACKGROUND_SET (15)
  ebx - SSF_REDRAW_BG (3)
======================================================================
== Function 15, subfunction 4 - set drawing mode for the background. =
======================================================================
Parameters:
  * eax = 15 - function number
  * ebx = 4 - subfunction number
  * ecx = drawing mode:
    * 1 = tile
    * 2 = stretch
Returned value:
  * function does not return value
Remarks:
  * For update of the screen (after completion of a series of commands
    working with a background) call subfunction 3.
  * There is a pair function for get drawing mode of the background -
    subfunction 4 of function 39.

---------------------- Constants for registers: ----------------------
  eax - SF_BACKGROUND_SET (15)
  ebx - SSF_MODE_BG (4)
======================================================================
===================== Function 15, subfunction 5 =====================
============ Put block of pixels on the background image. ============
======================================================================
Parameters:
  * eax = 15 - function number
  * ebx = 5 - subfunction number
  * ecx = pointer to the data in the format BBGGRRBBGGRR...
  * edx = offset in data of the background image
  * esi = size of data in bytes = 3 * number of pixels
Returned value:
  * function does not return value
Remarks:
  * Offset and size are not checked for correctness.
  * Color of each pixel is stored as 3-bytes value BBGGRR.
  * Pixels of the background image are written sequentially
    from left to right, from up to down.
  * Offset of pixel with coordinates (x,y) is (x+y*xsize)*3.
  * For update of the screen (after completion of a series of commands
    working with a background) call subfunction 3.

---------------------- Constants for registers: ----------------------
  eax - SF_BACKGROUND_SET (15)
  ebx - SSF_IMAGE_BG (5)
======================================================================
===================== Function 15, subfunction 6 =====================
======== Map background data to the address space of process. ========
======================================================================
Parameters:
  * eax = 15 - function number
  * ebx = 6 - subfunction number
Returned value:
  * eax = pointer to background data, 0 if error
Remarks:
  * Mapped data are available for read and write.
  * Size of background data is 3*xsize*ysize. The system blocks
    changes of background sizes while process works with mapped data.
  * Color of each pixel is stored as 3-bytes value BBGGRR.
  * Pixels of the background image are written sequentially
    from left to right, from up to down.

---------------------- Constants for registers: ----------------------
  eax - SF_BACKGROUND_SET (15)
  ebx - SSF_MAP_BG (6)
======================================================================
===== Function 15, subfunction 7 - close mapped background data. =====
======================================================================
Parameters:
  * eax = 15 - function number
  * ebx = 7 - subfunction number
  * ecx = pointer to mapped data
Returned value:
  * eax = 1 - success, 0 - error

---------------------- Constants for registers: ----------------------
  eax - SF_BACKGROUND_SET (15)
  ebx - SSF_UNMAP_BG (7)
======================================================================
===================== Function 15, subfunction 8 =====================
============= Get coordinates of last draw the background ============
======================================================================
Parameters:
  * eax = 15 - function number
  * ebx = 8 - subfunction number
Returned value:
  * eax = [left]*65536 + [right]
  * ebx = [top]*65536 + [bottom]
Remarks:
  * (left,top) are coordinates of the left upper corner,
    (right,bottom) are coordinates of the right lower one.
  * For receiving more reliable information, call the function
    immediately after the event:
             5 = kernel finished redrawing of the desktop background

---------------------- Constants for registers: ----------------------
  eax - SF_BACKGROUND_SET (15)
  ebx - SSF_LAST_DRAW (8)
======================================================================
===================== Function 15, subfunction 9 =====================
============= Redraws a rectangular part of the background ===========
======================================================================
Parameters:
  * eax = 15 - function number
  * ebx = 9 - subfunction number
  * ecx = [left]*65536 + [right]
  * edx = [top]*65536 + [bottom]
Returned value:
  * function does not return value
Remarks:
  * (left,top) are coordinates of the left upper corner,
    (right,bottom) are coordinates of the right lower one.
  * If parameters are set incorrectly then background is not redrawn.

---------------------- Constants for registers: ----------------------
  eax - SF_BACKGROUND_SET (15)
  ebx - SSF_REDRAW_RECT (9)
======================================================================
=============== Function 16 - save ramdisk on a floppy. ==============
======================================================================
Parameters:
  * eax = 16 - function number
  * ebx = 1 or ebx = 2 - on which floppy save
Returned value:
  * eax = 0 - success
  * eax = 1 - error

---------------------- Constants for registers: ----------------------
  eax - SF_RD_TO_FLOPPY (16)
======================================================================
======= Function 17 - get the identifier of the pressed button. ======
======================================================================
Takes away the code of the pressed button from the buffer.
Parameters:
  * eax = 17 - function number
Returned value:
  * if the buffer is empty, function returns eax=1
  * if the buffer is not empty:
    * high 24 bits of eax contain button identifier (in particular,
      ah contains low byte of the identifier; if all buttons have
      the identifier less than 256, ah is enough to distinguish)
    * al = 0 - the button was pressed with left mouse button
    * al = bit corresponding to used mouse button otherwise
Remarks:
  * "Buffer" keeps only one button, at pressing the new button the
    information about old is lost.
  * The call of this function by an application with inactive window
    will return answer "buffer is empty".
  * Returned value for al corresponds to the state of mouse buttons
    as in subfunction 2 of function 37 at the beginning
    of button press, excluding lower bit, which is cleared.

---------------------- Constants for registers: ----------------------
  eax - SF_GET_BUTTON (17)
======================================================================
===================== Function 18, subfunction 1 =====================
============= Make deactive the window of the given thread. ==========
======================================================================
Parameters:
  * eax = 18 - function number
  * ebx = 1 - subfunction number
  * ecx = number of the thread slot
Returned value:
  * function does not return value

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM (18)
  ebx - SSF_UNFOCUS_WINDOW (1)
======================================================================
= Function 18, subfunction 2 - terminate process/thread by the slot. =
======================================================================
Parameters:
  * eax = 18 - function number
  * ebx = 2 - subfunction number
  * ecx = number of the slot of process/thread
Returned value:
  * function does not return value
Remarks:
  * It is impossible to terminate system thread OS/IDLE (with
    number of the slot 1),
    it is possible to terminate any normal process/thread.
  * See also subfunction 18 - terminate
    process/thread by the identifier.

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM (18)
  ebx - SSF_TERMINATE_THREAD (2)
======================================================================
===================== Function 18, subfunction 3 =====================
============= Make active the window of the given thread. ============
======================================================================
Parameters:
  * eax = 18 - function number
  * ebx = 3 - subfunction number
  * ecx = number of the thread slot
Returned value:
  * function does not return value
Remarks:
  * If correct, but nonexistent slot is given,
    some window is made active.
  * To find out, which window is active, use subfunction 7.

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM (18)
  ebx - SSF_FOCUS_WINDOW (3)
======================================================================
===================== Function 18, subfunction 4 =====================
=========== Get counter of idle time units per one second. ===========
======================================================================
Idle time units are units, in which the processor stands idle
in waiting for interrupt (in the command 'hlt').

Parameters:
  * eax = 18 - function number
  * ebx = 4 - subfunction number
Returned value:
  * eax = value of the counter of idle time units per one second

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM (18)
  ebx - SSF_GET_IDLE_COUNT (4)
======================================================================
========== Function 18, subfunction 5 - get CPU clock rate. ==========
======================================================================
Parameters:
  * eax = 18 - function number
  * ebx = 5 - subfunction number
Returned value:
  * eax = clock rate (modulo 2^32 clock ticks = 4GHz)

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM (18)
  ebx - SSF_GET_CPU_REQUENCY (5)
======================================================================
 Function 18, subfunction 6 - save ramdisk to the file on hard drive.
======================================================================
Parameters:
  * eax = 18 - function number
  * ebx = 6 - subfunction number
  * ecx = pointer to the full path to file
    (for example, "/hd0/1/kolibri/kolibri.img")
Returned value:
  * eax = 0 - success
  * else eax = error code of the file system
Remarks:
  * All folders in the given path must exist, otherwise function
    returns value 5, "file not found".

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM (18)
  ebx - SSF_RD_TO_HDD (6)
======================================================================
=========== Function 18, subfunction 7 - get active window. ==========
======================================================================
Parameters:
  * eax = 18 - function number
  * ebx = 7 - subfunction number
Returned value:
  * eax = number of the active window
    (number of the slot of the thread with active window)
Remarks:
  * Active window is at the top of the window stack and receives
    messages on all keyboard input.
  * To make a window active, use subfunction 3.

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM (18)
  ebx - SSF_GET_ACTIVE_WINDOW (7)
======================================================================
== Function 18, subfunction 8 - disable/enable the internal speaker. =
======================================================================
If speaker sound is disabled, all calls to subfunction 55 of
function 55 are ignored. If speaker sound is enabled,
they are routed on builtin speaker.

------------------- Subsubfunction 1 - get status. -------------------
Parameters:
  * eax = 18 - function number
  * ebx = 8 - subfunction number
  * ecx = 1 - number of the subsubfunction
Returned value:
  * eax = 0 - speaker sound is enabled; 1 - disabled

----------------- Subsubfunction 2 - toggle status. ------------------
Toggles states of disable/enable.
Parameters:
  * eax = 18 - function number
  * ebx = 8 - subfunction number
  * ecx = 2 - number of the subsubfunction
Returned value:
  * function does not return value

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM (18)
  ebx - SSF_SPEAKER (8)
  ecx - SSSF_GET_STATE (1), SSSF_TOGGLE (2)
======================================================================
== Function 18, subfunction 9 - system shutdown with the parameter. ==
======================================================================
Parameters:
  * eax = 18 - function number
  * ebx = 9 - subfunction number
  * ecx = parameter:
    * 2 = turn off computer
    * 3 = reboot computer
    * 4 = restart the kernel from the file 'kernel.mnt' on ramdisk
Returned value:
  * at incorrect ecx the registers do not change (i.e. eax=18)
  * by correct call function always returns eax=0
    as the tag of success
Remarks:
  * Do not rely on returned value by incorrect call, it can be
    changed in future versions of the kernel.

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM (18)
  ebx - SSF_SHUTDOWN (9)
======================================================================
======= Function 18, subfunction 10 - minimize topmost window. =======
======================================================================
Minimizes the topmost (active) window.
Parameters:
  * eax = 18 - function number
  * ebx = 10 - subfunction number
Returned value:
  * function does not return value
Remarks:
  * The minimized window from the point of view of function 9
    keeps position and sizes.
  * Restoring of an application window occurs at its activation by
    subfunction 3.
  * Usually there is no necessity to minimize/restore a window
    explicitly: minimization of a window is carried out by the system
    at pressing the minimization button (for skinned windows
    it is defined automatically by function 0,
    for other windows it can be defined manually by function 8),
    restore of a window is done by the application '@taskbar'.

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM (18)
  ebx - SSF_MINIMIZE_WINDOW (10)
======================================================================
 Function 18, subfunction 11 - get information on the disk subsystem.
======================================================================
Parameters:
  * eax = 18 - function number
  * ebx = 11 - subfunction number
  * ecx = type of the table:
    * 1 = short version, 16 bytes
  * edx = pointer to the buffer (in the application) for the table
Returned value:
  * function does not return value
Format of the table: short version:
  * +0: byte: information about FDD's (drives for floppies),
    AAAABBBB, where AAAA gives type of the first drive, BBBB -
    of the second regarding to the following list:
    * 0 = there is no drive
    * 1 = 360Kb, 5.25''
    * 2 = 1.2Mb, 5.25''
    * 3 = 720Kb, 3.5''
    * 4 = 1.44Mb, 3.5''
    * 5 = 2.88Mb, 3.5'' (such drives are not used anymore)
    For example, for the standard configuration from one 1.44-drive
    here will be 40h, and for the case 1.2Mb on A: and 1.44Mb on B:
    the value is 24h.
    
  First IDE controller:
  * +1: byte: information about hard disks and CD-drives, AABBCCDD,
    where AA corresponds to the controller IDE0, ..., DD - IDE3:
    * 0 = device not found
    * 1 = hard drive
    * 2 = CD-drive
    For example, in the case HD on IDE0 and CD on IDE2
    this field contains 48h.
  * +2: 4 db: number of the retrieved partitions on hard disks
    at accordingly IDE0,...,IDE3.
    
  Second IDE controller:
  * +6: byte: information about hard disks and CD-drives, AABBCCDD,
    where AA corresponds to the controller IDE4, ..., DD - IDE7:
    * 0 = device not found
    * 1 = hard drive
    * 2 = CD-drive
    For example, in the case HD on IDE4 and CD on IDE6
    this field contains 48h.
  * +7: 4 db: number of the retrieved partitions on hard disks
    at accordingly IDE4,...,IDE7.

  Third IDE controller:
  * +11: byte: information about hard disks and CD-drives, AABBCCDD,
    where AA corresponds to the controller IDE8, ..., DD - IDE11:
    * 0 = device not found
    * 1 = hard drive
    * 2 = CD-drive
    For example, in the case HD on IDE8 and CD on IDE10
    this field contains 48h.
  * +12: 4 db: number of the retrieved partitions on hard disks
    at accordingly IDE8,...,IDE11.   
    
    If the hard disk on IDEx is absent, appropriate byte is zero,
    otherwise it shows number of the recognized partitions, which
    can be not presented (if the drive is not formatted or if
    the file system is not supported). Current version of the kernel
    supports only FAT12/16/32, NTFS, ext2/3/4 and XFS for hard disks.

Remarks:
  * The table can be used for obtaining the information about
    available devices.

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM (18)
  ebx - SSF_INFO_DISC_SYS (11)
======================================================================
========== Function 18, subfunction 13 - get kernel version. =========
======================================================================
Parameters:
  * eax = 18 - function number
  * ebx = 13 - subfunction number
  * ecx = pointer to the buffer (not less than 16 bytes), where
    the information will be placed
Returned value:
  * function does not return value
Structure of the buffer:
db a,b,c,d for version a.b.c.d
db 0: reserved
dd REV - kernel SVN revision number
For Kolibri 0.7.7.0+ kernel:
db 0,7,7,0
db 0
dd 1675

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM (18)
  ebx - SSF_KERNEL_VERSION (13)
======================================================================
======= Function 18, subfunction 14 - wait for screen retrace. =======
======================================================================
Waits for the beginning of retrace of the scanning ray of the screen
monitor.
Parameters:
  * eax = 18 - function number
  * ebx = 14 - subfunction number
Returned value:
  * eax = 0 as the tag of success
Remarks:
  * Function is intended only for active high-efficiency graphics
    applications; is used for smooth output of a graphics.

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM (18)
  ebx - SSF_WAIT_RETRACE (14)
======================================================================
== Function 18, subfunction 15 - center mouse cursor on the screen. ==
======================================================================
Parameters:
  * eax = 18 - function number
  * ebx = 15 - subfunction number
Returned value:
  * eax = 0 as the tag of success

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM (18)
  ebx - SSF_CURSOR_CENTER (15)
======================================================================
========= Function 18, subfunction 16 - get size of free RAM. ========
======================================================================
Parameters:
  * eax = 18 - function number
  * ebx = 16 - subfunction number
Returned value:
  * eax = size of free memory in kilobytes

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM (18)
  ebx - SSF_GET_FREE_RAM (16)
======================================================================
======== Function 18, subfunction 17 - get full amount of RAM. =======
======================================================================
Parameters:
  * eax = 18 - function number
  * ebx = 17 - subfunction number
Returned value:
  * eax = total size of existing memory in kilobytes

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM (18)
  ebx - SSF_GET_TOTAL_RAM (17)
======================================================================
===================== Function 18, subfunction 18 ====================
============= Terminate process/thread by the identifier. ============
======================================================================
Parameters:
  * eax = 18 - function number
  * ebx = 18 - subfunction number
  * ecx = identifer of process/thread (PID/TID)
Returned value:
  * eax = 0 - success
  * eax = -1 - error (process is not found or is system)
Remarks:
  * It is impossible to terminate system thread OS/IDLE (identifier
    1), it is possible to terminate any normal process/thread.
  * See also subfunction 2 - terminate
    process/thread by given slot.

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM (18)
  ebx - SSF_TERMINATE_THREAD_ID (18)
======================================================================
======== Function 18, subfunction 19 - get/set mouse features. =======
======================================================================

---------------- Subsubfunction 0 - get mouse speed. -----------------
Parameters:
  * eax = 18 - function number
  * ebx = 19 - subfunction number
  * ecx = 0 - subsubfunction number
Returned value:
  * eax = current mouse speed

---------------- Subsubfunction 1 - set mouse speed. -----------------
Parameters:
  * eax = 18 - function number
  * ebx = 19 - subfunction number
  * ecx = 1 - subsubfunction number
  * edx = new value for speed
Returned value:
  * function does not return value

Remark: recommended speed = 1, 0 = lock the cursor.

------------- Subsubfunction 2 - get mouse acceleration. -------------
Parameters:
  * eax = 18 - function number
  * ebx = 19 - subfunction number
  * ecx = 2 - subsubfunction number
Returned value:
  * eax = 0 - off, 1 - slight, 2 - medium, 3 - intense

------------- Subsubfunction 3 - set mouse acceleration. -------------
Parameters:
  * eax = 18 - function number
  * ebx = 19 - subfunction number
  * ecx = 3 - subsubfunction number
  * edx = 0 - off, 1 - slight, 2 - medium, 3 - intense
Returned value:
  * function does not return value

----------- Subsubfunction 4 - set mouse pointer position. -----------
Parameters:
  * eax = 18 - function number
  * ebx = 19 - subfunction number
  * ecx = 4 - subsubfunction number
  * edx = [coordinate on axis x]*65536 + [coordinate on axis y]
Returned value:
  * function does not return value

-------- Subsubfunction 5 - simulate state of mouse buttons. ---------
Parameters:
  * eax = 18 - function number
  * ebx = 19 - subfunction number
  * ecx = 5 - subsubfunction number
  * edx = information about emulated state of mouse buttons:
    (same as return value in subfunction 2 of function 37)
    * bit 0 is set = left button is pressed
    * bit 1 is set = right button is pressed
    * bit 2 is set = middle button is pressed
    * bit 3 is set = 4th button is pressed
    * bit 4 is set = 5th button is pressed
Returned value:
  * function does not return value

-------------- Subsubfunction 6 - get doubleclick delay. -------------
Parameters:
  * eax = 18 - function number
  * ebx = 19 - subfunction number
  * ecx = 6 - subsubfunction number
Returned value:
  * eax = current doubleclick delay (100 = 1 second)

-------------- Subsubfunction 7 - set doubleclick delay. -------------
Parameters:
  * eax = 18 - function number
  * ebx = 19 - subfunction number
  * ecx = 7 - subsubfunction number
  * dl  = new value for doubleclick delay (100 = 1 second)
Returned value:
  * function does not return value

Remark: mouse settings can be modified in the application mouse_cfg.

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM (18)
  ebx - SSF_MOUSE_SETTINGS (19)
  ecx - SSSF_GET_SPEED (0), SSSF_SET_SPEED (1), SSSF_GET_SPEEDUP (2),
    SSSF_SET_SPEEDUP (3), SSSF_SET_POS (4), SSSF_SET_BUTTON (5),
    SSSF_GET_DOUBLE_CLICK_DELAY (6), SSSF_SET_DOUBLE_CLICK_DELAY (7)
======================================================================
======== Function 18, subfunction 20 - get information on RAM. =======
======================================================================
Parameters:
  * eax = 18 - function number
  * ebx = 20 - subfunction number
  * ecx = pointer to the buffer for information (36 bytes)
Returned value:
  * eax = total size of existing RAM in pages
    or -1 if error has occured
  * buffer pointed to by ecx contains the following information:
    * +0:  dword: total size of existing RAM in pages
    * +4:  dword: size of free RAM in pages
    * +8:  dword: number of page faults (exceptions #PF)
                 in applications
    * +12: dword: size of kernel heap in bytes
    * +16: dword: free in kernel heap in bytes
    * +20: dword: total number of memory blocks in kernel heap
    * +24: dword: number of free memory blocks in kernel heap
    * +28: dword: size of maximum free block in kernel heap
                 (reserved)
    * +32: dword: size of maximum allocated block in kernel heap
                 (reserved)

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM (18)
  ebx - SSF_GET_RAM_INFO (20)
======================================================================
===================== Function 18, subfunction 21 ====================
======== Get slot number of process/thread by the identifier. ========
======================================================================
Parameters:
  * eax = 18 - function number
  * ebx = 21 - subfunction number
  * ecx = identifer of process/thread (PID/TID)
Returned value:
  * eax = 0 - error (invalid identifier)
  * otherwise eax = slot number

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM (18)
  ebx - SSF_GET_THREAD_SLOT (21)
======================================================================
===================== Function 18, subfunction 22 ====================
============== Operations with window of another thread. =============
======================================================================
Parameters:
  * eax = 18 - function number
  * ebx = 22 - subfunction number
  * ecx = operation type:
    * 0 = minimize window of the thread with given slot number
    * 1 = minimize window of the thread with given identifier
    * 2 = restore window of the thread with given slot number
    * 3 = restore window of the thread with given identifier
  * edx = parameter (slot number or PID/TID)
Returned value:
  * eax = 0 - success
  * eax = -1 - error (invalid identifier)
Remarks:
  * The thread can minimize its window with subfunction 10.
  * One can restore and activate window simultaneously with
    subfunction 3 (which requires slot number).

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM (18)
  ebx - SSF_FOREIGN_WINDOW (22)
  ecx - SSSF_MINIMIZE (0), SSSF_MINIMIZE_ID (1), SSSF_RESTORE (2),
    SSSF_RESTORE_ID (3)
======================================================================
======== Function 18, subfunction 23 - minimize all windows. ==========
======================================================================
Parameters:
  * eax = 18 - function number
  * ebx = 23 - subfunction number
Returned value:
  * eax = 0 - all windows have been minimized before a function call
  * eax = N - number of windows minimized from function
Remarks:
  * Window of special thread (name begin to symbol @) is not minimize.

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM (18)
  ebx - SSF_MINIMIZE_ALL (23)
======================================================================
======= Function 18, subfunction 24 - set limits of screen. ==========
======================================================================
Parameters:
  * eax = 18 - function number
  * ebx = 24 - subfunction number
  * ecx = new X size
  * edx = new Y size
Returned value:
  * function does not return value
Remarks:
  * The function does not change the physical size of the video mode.
    It is designed for non-standard displays which display the image
    partially.
  * The sizes specified in the function should not exceed the sizes
    of the current video mode, otherwise the function will not change
    anything.

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM (18)
  ebx - SSF_SET_SCREEN_LIMITS (24)
======================================================================
===================== Function 18, subfunction 25 ====================
===== Control position of the window relative to other windows. ======
======================================================================

------------- Subsubfunction 1 - get position  -----------------------
Parameters:
  * eax = 18 - function number
  * ebx = 25 - subfunction number
  * ecx = 1 - subsubfunction number
  * edx = -1(for current window) or PID application
Returned value:
  * eax = one of the constants window position

------------- Subsubfunction 2 - set position  -----------------------
Parameters:
  * eax = 18 - function number
  * ebx = 25 - subfunction number
  * ecx = 2 - subsubfunction number
  * edx = -1(for current window) or PID application
  * esi = new window position (one of the constants below)
Returned value:
  * eax = 0 - error
  * eax = 1 - success

Constant position of the window relative to other windows:
 ZPOS_DESKTOP     = -2 - on the background
 ZPOS_ALWAYS_BACK = -1 - behind all the windows
 ZPOS_NORMAL      = 0  - normal
 ZPOS_ALWAYS_TOP  = 1  - on top of all windows

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM (18)
  ebx - SSF_WINDOW_BEHAVIOR (25)
  ecx - SSSF_GET_WB (1), SSSF_SET_WB (2)
======================================================================
==================== Function 20 - MIDI interface. ===================
======================================================================

----------------------- Subfunction 1 - reset ------------------------
Parameters:
  * eax = 20 - function number
  * ebx = 1 - subfunction number

-------------------- Subfunction 2 - output byte ---------------------
Parameters:
  * eax = 20 - function number
  * ebx = 2 - subfunction number
  * cl = byte for output
Returned value (is the same for both subfunctions):
  * eax = 0 - success
  * eax = 1 - base port is not defined
Remarks:
  * Previously the base port must be defined by
    subfunction 1 of function 21.

---------------------- Constants for registers: ----------------------
  eax - SF_MIDI (20)
  ebx - SSF_RESET (1), SSF_OUTPUT (2)
======================================================================
======== Function 21, subfunction 1 - set MPU MIDI base port. ========
======================================================================
Parameters:
  * eax = 21 - function number
  * ebx = 1 - subfunction number
  * ecx = number of base port
Returned value
  * eax = 0 - success
  * eax = -1 - erratic number of a port
Remarks:
  * Number of a port must satisfy to conditions 0x100<=ecx<=0xFFFF.
  * The installation of base is necessary for function 20.
  * To get base port use subfunction 1 of function 26.

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM_SET (21)
  ebx - SSF_MPU_MIDI_BASE (1)
======================================================================
========== Function 21, subfunction 2 - set keyboard layout. =========
======================================================================
Keyboard layout is used to convert keyboard scancodes to ASCII-codes,
which will be read by function 2.
Parameters:
  * eax = 21 - function number
  * ebx = 2 - subfunction number
  * ecx = which layout to set:
    * 1 = normal layout
    * 2 = layout at pressed Shift
    * 3 = layout at pressed Alt
  * edx = pointer to layout - table of length 128 bytes
Or:
  * ecx = 9
  * dx = country identifier (1=eng, 2=fi, 3=ger, 4=rus)
Returned value:
  * eax = 0 - success
  * eax = 1 - incorrect parameter
Remarks:
  * If Alt is pressed, the layout with Alt is used;
    if Alt is not pressed, but Shift is pressed,
    the layout with Shift is used;
    if Alt and Shift are not pressed, but Ctrl is pressed, the normal
    layout is used and then from the code is subtracted 0x60;
    if no control key is pressed, the normal layout is used.
  * To get layout and country identifier use
    subfunction 2 of function 26.
  * Country identifier is global system variable, which is not used
    by the kernel itself; however the application '@taskbar' displays
    the corresponding icon.
  * The application @taskbar switches layouts on user request.

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM_SET (21)
  ebx - SSF_KEYBOARD_LAYOUT (2)
======================================================================
========== Function 21, subfunction 5 - set system language. =========
======================================================================
Parameters:
  * eax = 21 - function number
  * ebx = 5 - subfunction number
  * ecx = system language (1=eng, 2=fi, 3=ger, 4=rus)
Returned value:
  * eax = 0
Remarks:
  * System language is global system variable and is not used
    by the kernel itself, however application @taskbar draws the
    appropriate icon.
  * Function does not check for correctness, as the kernel does not
    use this variable.
  * To get system language use subfunction 5 of function 26.

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM_SET (21)
  ebx - SSF_SYS_LANG (5)
======================================================================
 Function 21, subfunction 11 - enable/disable low-level access to HD.
======================================================================
Parameters:
  * eax = 21 - function number
  * ebx = 11 - subfunction number
  * ecx = 0/1 - disable/enable
Returned value:
  * eax = 0
Remarks:
  * Is used in LBA-read (subfunction 8 of function 58).
  * The current implementation uses only low bit of ecx.
  * To get current status use subfunction 11 of function 26.

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM_SET (21)
  ebx - SSF_ACCESS_HD_LBA (11)
======================================================================
 Function 21, subfunction 12 - enable/disable low-level access to PCI.
======================================================================
Parameters:
  * eax = 21 - function number
  * ebx = 12 - subfunction number
  * ecx = 0/1 - disable/enable
Returned value:
  * eax = 0
Remarks:
  * Is used in operations with PCI bus (function 62).
  * The current implementation uses only low bit of ecx.
  * To get current status use subfunction 12 of function 26.

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM_SET (21)
  ebx - SSF_ACCESS_PCI (12)
======================================================================
================= Function 22 - set system date/time. ================
======================================================================
Parameters:
  * eax = 22 - function number
  * ebx = 0 - set time
    * ecx = 0x00SSMMHH - time in the binary-decimal code (BCD):
    * HH=hour 00..23
    * MM=minute 00..59
    * SS=second 00..59
  * ebx = 1 - set date
    * ecx = 0x00DDMMYY - date in the binary-decimal code (BCD):
    * DD=day 01..31
    * MM=month 01..12
    * YY=year 00..99
  * ebx = 2 - set day of week
    * ecx = 1 for Sunday, ..., 7 for Saturday
  * ebx = 3 - set alarm clock
    * ecx = 0x00SSMMHH
Returned value:
  * eax = 0 - success
  * eax = 1 - incorrect parameter
  * eax = 2 - CMOS-battery was unloaded
Remarks:
  * Value of installation of day of week seems to be doubtful,
    as it a little where is used
    (day of week can be calculated by date).
  * Alarm clock can be set on operation in the given time every day.
    But there is no existing system function to disable it.
  * Operation of alarm clock consists in generation IRQ8.
  * Generally CMOS supports for alarm clock set of value 0xFF
    as one of parameters and it means that the appropriate parameter
    is ignored. But current implementation does not allow this
    (will return 1).
  * Alarm clock is a global system resource; the set of
    an alarm clock cancels automatically the previous set.
    However, at moment no program uses it.

---------------------- Constants for registers: ----------------------
  eax - SF_SET_TIME_DATE (22)
======================================================================
============= Function 23 - wait for event with timeout. =============
======================================================================
If the message queue is empty, waits for new message in the queue,
but no more than given time. Then reads out a message from the queue.

Parameters:
  * eax = 23 - function number
  * ebx = timeout (in 1/100 of second)
Returned value:
  * eax = 0 - the message queue is empty
  * otherwise eax = event (see the list of events)
Remarks:
  * Only those events are taken into account, which enter into
    the mask set by function 40. By default it is
    redraw, key and button events.
  * To check for presence of a message in the queue use function 11.
    To wait without timeout use function 10.
  * Transmission ebx=0 results in immediate returning eax=0.
  * Current implementation returns immediately with eax=0,
    if the addition of ebx with the current value of time counter
    makes 32-bit overflow.

---------------------- Constants for registers: ----------------------
  eax - SF_WAIT_EVENT_TIMEOUT (23)
======================================================================
======= Function 24, subfunction 4 - eject tray of disk drive. =======
======================================================================
Parameters:
  * eax = 24 - function number
  * ebx = 4 - subfunction number
  * ecx = position of CD/DVD-drive
    from 0=Primary Master to 3=Secondary Slave for first IDE contr.
    from 4=Primary Master to 7=Secondary Slave for second IDE contr.
    from 8=Primary Master to 11=Secondary Slave for third IDE contr.
Returned value:
  * function does not return value
Remarks:
  * The function is supported only for ATAPI devices (CD and DVD).
  * When the tray is being ejected,
    manual control of tray is unlocked.
  * When the tray is being ejected, the code clears the cache for
    corresponding device.
  * An example of usage of the function is the application CD_tray.

---------------------- Constants for registers: ----------------------
  eax - SF_CD (24)
  ebx - SSF_EJECT_TRAY (4), SSF_INSERT_TRAY (5)
======================================================================
======== Function 24, subfunction 5 - load tray of disk drive. =======
======================================================================
Parameters:
  * eax = 24 - function number
  * ebx = 5 - subfunction number
  * ecx = position of CD/DVD-drive
    from 0=Primary Master to 3=Secondary Slave for first IDE contr.
    from 4=Primary Master to 7=Secondary Slave for second IDE contr.
    from 8=Primary Master to 11=Secondary Slave for third IDE contr.
Returned value:
  * function does not return value
Remarks:
  * The function is supported only for ATAPI devices (CD and DVD).
  * An example of usage of the function is the application CD_tray.

---------------------- Constants for registers: ----------------------
  eax - SF_CD (24)
  ebx - SSF_EJECT_TRAY (4), SSF_INSERT_TRAY (5)
======================================================================
======= Function 25 - put image area on the background layer. ========
======================================================================
Paramters:
  * eax = 25 - function number
  * ebx = pointer to the previously allocated memory area,
        where placed the source images in a format BBGGRRTTBBGGRRTT...
  * ecx = [size on axis x]*65536 + [size on axis y]
  * edx = [coordinate on axis x]*65536 + [coordinate on axis y]
Returned value:
  * function does not return value
Remarks:
  * Coordinates of the image are coordinates of the upper left corner
    of the image relative to the screen.
  * Size of the image in bytes is 4*xsize*ysize
  * TT - byte pointer of transparency, at current version:
         1 to FF - opaque, 0 - transparent.
  * The function places the image directly to LFB. It is not for
    background image f.15. Options f.15 to f.25 does not make sense.

---------------------- Constants for registers: ----------------------
  eax - SF_SCREEN_PUT_IMAGE (25)
======================================================================
======== Function 26, subfunction 1 - get MPU MIDI base port. ========
======================================================================
Parameters:
  * eax = 26 - function number
  * ebx = 1 - subfunction number
Returned value:
  * eax = port number
Parameters:
  * To set base port use subfunction 1 of function 21.

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM_GET (26)
  ebx - SSF_MPU_MIDI_BASE (1)
======================================================================
========== Function 26, subfunction 2 - get keyboard layout. =========
======================================================================
The keyboard layout is used to convert keyboard scancodes to
ASCII-codes for function 2.
Parameters:
  * eax = 26 - function number
  * ebx = 2 - subfunction number
  * ecx = what layout to get:
    * 1 = normal layout
    * 2 = layout with pressed Shift
    * 3 = layout with pressed Alt
  * edx = pointer to the 128-bytes buffer, where the layout will be
    copied
Returned value:
  * function does not return value
Or:
  * eax = 26 - function number
  * ebx = 2 - subfunction number
  * ecx = 9
Returned value:
  * eax = country identifier (1=eng, 2=fi, 3=ger, 4=rus)
Remarks:
  * If Alt is pressed, the layout with Alt is used;
    if Alt is not pressed, but Shift is pressed,
    the layout with Shift is used;
    if Alt and Shift are not pressed, but Ctrl is pressed, the normal
    layout is used and then from the code is subtracted 0x60;
    if no control key is pressed, the normal layout is used.
  * To set layout and country identifier use
    subfunction 2 of function 21.
  * Country identifier is global system variable, which is not used
    by the kernel itself; however the application '@taskbar' displays
    the corresponding icon (using this function).
  * The application @taskbar switches layouts on user request.

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM_GET (26)
  ebx - SSF_KEYBOARD_LAYOUT (2)
======================================================================
========== Function 26, subfunction 5 - get system language. =========
======================================================================
Parameters:
  * eax = 26 - function number
  * ebx = 5 - subfunction number
Returned value:
  * eax = system language (1=eng, 2=fi, 3=ger, 4=rus)
Remarks:
  * System language is global system variable and is not used
    by the kernel itself, however application @taskbar draws the
    appropriate icon (using this function).
  * To set system language use subfunction 5 of function 21.

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM_GET (26)
  ebx - SSF_SYS_LANG (5)
======================================================================
=== Function 26, subfunction 9 - get the value of the time counter. ==
======================================================================
Parameters:
  * eax = 26 - function number
  * ebx = 9 - subfunction number
Returned value:
  * eax = number of 1/100s of second, past from the system boot time
Remarks:
  * Counter takes modulo 2^32, that correspond to a little more
    than 497 days.
  * To get system time use function 3.  

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM_GET (26)
  ebx - SSF_TIME_COUNT (9)
======================================================================
===================== Function 26, subfunction 10 ====================
========== Get the value of the high precision time counter. =========
======================================================================
Parameters:
  * eax = 26 - function number
  * ebx = 10 - subfunction number
Returned value:
  * eax = number of nanoseconds since system boot time (lower DWORD)
  * edx = number of nanoseconds since system boot time (high DWORD)  
Remarks:
  * The counter is based on HPET, if HPET is not available, resolution
    will be reduced to 10 000 000 nanoseconds.

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM_GET (26)
  ebx - SSF_TIME_COUNT_PRO (10)
======================================================================
===================== Function 26, subfunction 11 ====================
========== Find out whether low-level HD access is enabled. ==========
======================================================================
Parameters:
  * eax = 26 - function number
  * ebx = 11 - subfunction number
Returned value:
  * eax = 0/1 - disabled/enabled
Remarks:
  * Is used in LBA read (subfunction 8 of function 58).
  * To set current state use subfunction 11 of function 21.

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM_GET (26)
  ebx - SSF_ACCESS_HD_LBA (11)
======================================================================
===================== Function 26, subfunction 12 ====================
========== Find out whether low-level PCI access is enabled. =========
======================================================================
Parameters:
  * eax = 26 - function number
  * ebx = 12 - subfunction number
Returned value:
  * eax = 0/1 - disabled/enabled
Remarks:
  * Is used by operations with PCI bus (function 62).
  * The current implementation uses only low bit of ecx.
  * To set the current state use subfunction 12 of function 21.

---------------------- Constants for registers: ----------------------
  eax - SF_SYSTEM_GET (26)
  ebx - SSF_ACCESS_PCI (12)
======================================================================
=================== Function 29 - get system date. ===================
======================================================================
Parameters:
  * eax = 29 - function number
Returned value:
  * eax = 0x00DDMMYY, where
    (binary-decimal coding, BCD, is used)
  * YY = two low digits of year (00..99)
  * MM = month (01..12)
  * DD = day (01..31)
Remarks:
  * To set system date use function 22.

---------------------- Constants for registers: ----------------------
  eax - SF_GET_SYS_DATE (29)
======================================================================
============= Function 30 - work with the current folder. ============
======================================================================

--------- Subfunction 1 - set current folder for the thread. ---------
Parameters:
  * eax = 30 - function number
  * ebx = 1 - subfunction number
  * ecx = pointer to ASCIIZ-string with the path to new current folder
Returned value:
  * function does not return value

--------- Subfunction 2 - get current folder for the thread. ---------
Parameters:
  * eax = 30 - function number
  * ebx = 2 - subfunction number
  * ecx = pointer to buffer
  * edx = size of buffer
Returned value:
  * eax = size of the current folder's name (including terminating 0)
Remarks:
  * If the buffer is too small to hold all data, only first (edx-1)
    bytes are copied and than terminating 0 is inserted.
  * By default, current folder for the thread is "/rd/1".
  * At process/thread creation the current folder will be inherited
    from the parent.

--- Subfunction 3 - install the add.system directory for the kernel --
Parameters:
  * eax = 30 - function number
  * ebx = 3 - subfunction number
  * ecx = pointer to a block of data:
          sysdir_name     rb 64
          sysdir_path     rb 64
For example:
dir_name1       db 'KolibriOS',0
                rb 64-10
dir_path1       db 'HD0/1',0
                rb 64-6
Returned value:
  * function does not return value
Remarks:
  * The function can be called only 1 time for 1 session of the OS.

---------------------- Constants for registers: ----------------------
  eax - SF_CURRENT_FOLDER (30)
  ebx - SSF_SET_CF (1), SSF_GET_CF (2), SSF_ADD_SYS_FOLDER (3)
======================================================================
========= Function 34 - who owner the pixel on the screen. ===========
======================================================================
Parameters:
  * eax = 34 - function number
  * ebx = x-coordinate (relative to the display)
  * ecx = y-coordinate (relative to the display)

Returned value:
  * eax = 0x000000XX - owner of pixel the slot window N
    If incorrect values ebx and ecx then function returns 0
  * The function takes the value from the area [_WinMapAddress]

---------------------- Constants for registers: ----------------------
  eax - SF_GET_PIXEL_OWNER (34)
======================================================================
======= Function 35 - read the color of a pixel on the screen. =======
======================================================================
Parameters:
  * eax = 35
  * ebx = y*xsize+x, where
  * (x,y) = coordinates of a pixel (beginning from 0)
  * xsize = horizontal screen size
Returned value:
  * eax = color 0x00RRGGBB
Remarks:
  * To get screen sizes use function 14. Pay attention,
    that it subtracts 1 from both sizes.
  * There is also direct access (without any system calls)
    to videomemory through the selector gs. To get parameters of
    the current videomode, use function 61.

---------------------- Constants for registers: ----------------------
  eax - SF_GET_PIXEL (35)
======================================================================
=================== Function 36 - read screen area. ==================
======================================================================
Paramters:
  * eax = 36 - function number
  * ebx = pointer to the previously allocated memory area,
        where will be placed the image in the format BBGGRRBBGGRR...
  * ecx = [size on axis x]*65536 + [size on axis y]
  * edx = [coordinate on axis x]*65536 + [coordinate on axis y]
Returned value:
  * function does not return value
Remarks:
  * Coordinates of the image are coordinates of the upper left corner
    of the image relative to the screen.
  * Size of the image in bytes is 3*xsize*ysize.

---------------------- Constants for registers: ----------------------
  eax - SF_GET_IMAGE (36)
======================================================================
=================== Function 37 - work with mouse. ===================
======================================================================

---------- Subfunction 0 - screen coordinates of the mouse -----------
Parameters:
  * eax = 37 - function number
  * ebx = 0 - subfunction number
Returned value:
  * eax = x*65536 + y, (x,y)=coordinates of the mouse pointer
    (beginning from 0)

-- Subfunction 1 - coordinates of the mouse relative to the window ---
Parameters:
  * eax = 37 - function number
  * ebx = 1 - subfunction number
Returned value:
  * eax = x*65536 + y, (x,y)=coordinates of the mouse pointer
    relative to the application window (beginning from 0)
Remarks:
  * The value is calculated by formula (x-xwnd)*65536 + (y-ywnd).
    If y>=ywnd, the low word is non-negative and contains
    relative y-coordinate, and the high word - relative x-coordinate
    (with correct sign). Otherwise the low word is negative and still
    contains relative y-coordinate, and to the high word
    1 should be added.

------------- Subfunction 2 - states of the mouse buttons ------------
Parameters:
  * eax = 37 - function number
  * ebx = 2 - subfunction number
Returned value:
  * eax = bits 0-4 equal to subfunction 3

------- Subfunction 3 - states and events of the mouse buttons -------
Parameters:
  * eax = 37 - function number
  * ebx = 3 - subfunction number
Returned value:
  * eax contains next information:

states:
  * bit 0 is set = left button is held
  * bit 1 is set = right button is held
  * bit 2 is set = middle button is held
  * bit 3 is set = 4th button is held
  * bit 4 is set = 5th button is held

events:
  * bit 8 is set = left button is pressed
  * bit 9 is set = right button is pressed
  * bit 10 is set = middle button is pressed

  * bit 15 is set = vertical scroll is used

  * bit 16 is set = left button is released
  * bit 17 is set = right button is released
  * bit 18 is set = middle button is released

  * bit 23 is set = horisontal scroll is used

  * bit 24 is set = doubleclick by left button

-------------------- Subfunction 4 - load cursor ---------------------
Parameters:
  * eax = 37 - function number
  * ebx = 4 - subfunction number
  * dx = data source:
  * dx = LOAD_FROM_FILE = 0 - data in a file
    * ecx = pointer to full path to the cursor file
    * the file must be in the format .cur, which is standard for
      MS Windows, at that of the size 32*32 pixels
  * dx = LOAD_FROM_MEM = 1 - data of file are already loaded in memory
    * ecx = pointer to data of the cursor file
    * the data format is the same as in the previous case
  * dx = LOAD_INDIRECT = 2 - data in memory
    * ecx = pointer to cursor image in the format ARGB 32*32 pixels
    * edx = 0xXXYY0002, where
      * XX = x-coordinate of cursor hotspot
      * YY = y-coordinate
      * 0 <= XX, YY <= 31
Returned value:
  * eax = 0 - failed
  * otherwise eax = cursor handle

--------------------- Subfunction 5 - set cursor ---------------------
Sets new cursor for the window of the current thread.
Parameters:
  * eax = 37 - function number
  * ebx = 5 - subfunction number
  * ecx = cursor handle
Returned value:
  * eax = handle of previous cursor
Remarks:
  * If the handle is incorrect, the function restores the default
    cursor (standard arrow). In particular, ecx=0 restores it.

------------------- Subfunction 6 - delete cursor --------------------
Parameters:
  * eax = 37 - function number
  * ebx = 6 - subfunction number
  * ecx = cursor handle
Returned value:
  * eax destroyed
Remarks:
  * The cursor must be loaded previously by the current thread
    (with the call to subfunction 4). The function does not delete
    system cursors and cursors, loaded by another applications.
  * If the active cursor (set by subfunction 5) is deleted,
    the system restores the default cursor (standard arrow).

------------------ Subfunction 7 - get scroll data -------------------
Parameters:
  * eax = 37 - function number
  * ebx = 7 - subfunction number
Returned value:
  * eax = [horizontal offset]*65536 + [vertical offset]
Remarks:
  * Scroll data is available for active window only.
  * Values are zeroed after reading.
  * Values are signed.

---------------------- Constants for registers: ----------------------
  eax - SF_MOUSE_GET (37)
  ebx - SSF_SCREEN_POSITION (0), SSF_WINDOW_POSITION (1),
    SSF_BUTTON (2), SSF_BUTTON_EXT (3), SSF_LOAD_CURSOR (4),
    SSF_SET_CURSOR (5), SSF_DEL_CURSOR (6), SSF_SCROLL_DATA (7)
======================================================================
====================== Function 38 - draw line. ======================
======================================================================
Parameters:
  * eax = 38 - function number
  * ebx = [start coordinate on axis x]*65536 +
              [end coordinate on axis x]
  * ecx = [start coordinate on axis y]*65536 +
              [end coordinate on axis y]
  * edx = 0x00RRGGBB - color
    edx = 0x01xxxxxx - draw inversed line
          (low 24 bits are ignored)
Returned value:
  * function does not return value
Remarks:
  * Coordinates are relative to the window.
  * End point is also drawn.

---------------------- Constants for registers: ----------------------
  eax - SF_DRAW_LINE (38)
======================================================================
== Function 39, subfunction 1 - get a size of the background image. ==
======================================================================
Parameters:
  * eax = 39 - function number
  * ebx = 1 - subfunction number
Returned value:
  * eax = [width]*65536 + [height]
Remarks:
  * There is a pair function to set sizes of background image -
    subfunction 1 of function 15. After which it is necessary,
    of course, anew to define image.

---------------------- Constants for registers: ----------------------
  eax - SF_BACKGROUND_GET (39)
======================================================================
== Function 39, subfunction 2 - get pixel from the background image. =
======================================================================
Parameters:
  * eax = 39 - function number
  * ebx = 2 - subfunction number
  * ecx = offset
Returned value:
  * eax = 0x00RRGGBB - pixel color, if offset is valid
    (less than 0x160000-16)
  * eax = 2 otherwise
Remarks:
  * Do not rely on returned value for invalid offsets, it may be
    changed in future kernel versions.
  * Offset for pixel with coordinates (x,y)
    is calculated as (x+y*xsize)*3.
  * There is a pair function to set pixel on the background image -
    subfunction 2 of function 15.

---------------------- Constants for registers: ----------------------
  eax - SF_BACKGROUND_GET (39)
======================================================================
== Function 39, subfunction 4 - get drawing mode for the background. =
======================================================================
Parameters:
  * eax = 39 - function number
  * ebx = 4 - subfunction number
Returned value:
  * eax = 1 - tile
  * eax = 2 - stretch
Remarks:
  * There is a pair function to set drawing mode -
    subfunction 4 of function 15.

---------------------- Constants for registers: ----------------------
  eax - SF_BACKGROUND_GET (39)
======================================================================
=========== Function 40 - set the mask for expected events. ==========
======================================================================
The mask for expected events affects function working with events
10, 11, 23 - they notify only about events allowed by this mask.
Parameters:
  * eax = 40 - function number
  * ebx = mask: bit i corresponds to event i+1 (see list of events)
    (set bit permits notice on event)
    bit 31: mouse active/inactive filter
    bit 31 = 0 - inactive window receive mouse events
    bit 31 = 1 - inactive window does not receive mouse events
    bit 30: cursor position filter
    bit 30 = 0 = the window receive mouse events if cursor
                 outside window
    bit 30 = 1 - the window does not receive mouse events if cursor
                 outside window
Returned value:
  * eax = previous value of mask
Remarks:
  * Default mask (7=111b) enables nofices about redraw,
    keys and buttons. This is enough for many applications.
  * Events prohibited in the mask are saved anyway, when come;
    they are simply not informed with event functions.
  * Event functions take into account the mask on moment of
    function call, not on moment of event arrival.

---------------------- Constants for registers: ----------------------
  eax - SF_SET_EVENTS_MASK (40)
======================================================================
================ Function 43 - input/output to a port. ===============
======================================================================

------------------------ Output data to port -------------------------
Parameters:
  * eax = 43 - function number
  * bl = byte for output
  * ecx = port number 0xnnnn (from 0 to 0xFFFF)
Returned value:
  * eax = 0 - success
  * eax = 1 - the thread has not reserved the selected port

------------------------ Input data from port ------------------------
Parameters:
  * eax = 43 - function number
  * ebx is ignored
  * ecx = 0x8000nnnn, where nnnn = port number (from 0 to 0xFFFF)
Returned value:
  * eax = 0 - success, thus ebx = entered byte
  * eax = 1 - the thread has not reserved the selected port
Remarks:
  * Previously the thread must reserve the selected port
    for itself by function 46.
  * Instead of call to this function it is better to use
    processor instructions in/out - this is much
    faster and a bit shorter and easier.

---------------------- Constants for registers: ----------------------
  eax - SF_PORT_IN_OUT (43)
======================================================================
====== Function 46 - reserve/free a group of input/output ports. =====
======================================================================
To work with reserved ports an application can access directly by
commands in/out (recommended way) and can use function 43
(not recommended way).
Parameters:
  * eax = 46 - function number
  * ebx = 0 - reserve, 1 - free
  * ecx = start port number
  * edx = end port number (inclusive)
Returned value:
  * eax = 0 - success
  * eax = 1 - error
Remarks:
  * For ports reservation: an error occurs if and only if
    one from the following condition satisfies:
    * start port is more than end port;
    * the selected range contains incorrect port number
      (correct are from 0 to 0xFFFF);
    * limit for the total number of reserved areas is exceeded
      (maximum 255 are allowed);
    * the selected range intersects with any of earlier reserved
  * For ports free: an error is an attempt to free range,
    that was not earlier reserved by this function
    (with same ecx,edx).
  * If an error occurs (for both cases) function performs no action.
  * At booting the system reserves for itself ports
    0..0x2d, 0x30..0x4d, 0x50..0xdf, 0xe5..0xff (inclusively).
  * When a thread terminates, all reserved by it ports
    are freed automatically.

---------------------- Constants for registers: ----------------------
  eax - SF_SET_PORTS (46)
======================================================================
============= Function 47 - draw a number in the window. =============
======================================================================
Parameters:
  * eax = 47 - function number
  * ebx = parameters of conversion number to text:
    * bl = 0 - ecx contains number
    * bl = 1 - ecx contains pointer to dword/qword-number
    * bh = 0 - display in decimal number system
    * bh = 1 - display in hexadecimal system
    * bh = 2 - display in binary system
    * bits 16-21 = how many digits to display
    * bits 22-29 reserved and must be set to 0
    * bit 30 set = display qword (64-bit) number (must be bl=1)
    * bit 31 set = do not display leading zeroes of the number
  * ecx = number (if bl=0) or pointer (if bl=1)
  * edx = [coordinate on axis x]*65536 + [coordinate on axis y]
  * esi = 0xX0RRGGBB:
    * RR, GG, BB specify the color
    * X = ABnn (bits)
    * nn = font (0/1)
    * A is ignored
    * B=1 - fill background with the color edi
Returned value:
  * function does not return value
Remarks:
  * The given length must not exceed 60.
  * The exactly given amount of digits is output. If number is small
    and can be written by smaller amount of digits, it is supplemented
    by leading zeroes; if the number is big and can not be written by
    given amount of digits, extra digits are not drawn.
  * Parameters of fonts are shown in the description of function 4
    (text output).

---------------------- Constants for registers: ----------------------
  eax - SF_DRAW_NUMBER (47)
======================================================================
========= Function 48, subfunction 0 - apply screen settings. ========
======================================================================
Parameters:
  * eax = 48 - function number
  * ebx = 0 - subfunction number
  * ecx = 0 - reserved
Returned value:
  * function does not return value
Remarks:
  * Function redraws the screen after parameters change by
    subfunctions 1 and 2.
  * Function call without prior call to one of indicated subfunctions
    is ignored.
  * Function call with nonzero ecx is ignored.

---------------------- Constants for registers: ----------------------
  eax - SF_STYLE_SETTINGS (48)
  ebx - SSF_APPLY (0)
======================================================================
=========== Function 48, subfunction 1 - set button style. ===========
======================================================================
Parameters:
  * eax = 48 - function number
  * ebx = 1 - subfunction number
  * ecx = button style:
    * 0 = flat
    * 1 = 3d
Returned value:
  * function does not return value
Remarks:
  * After call to this function one should redraw the screen by
    subfunction 0.
  * Button style influences only to their draw of function 8.

---------------------- Constants for registers: ----------------------
  eax - SF_STYLE_SETTINGS (48)
  ebx - SSF_SET_BUTTON_STYLE (1)
======================================================================
====== Function 48, subfunction 2 - set standard window colors. ======
======================================================================
Parameters:
  * eax = 48 - function number
  * ebx = 2 - subfunction number
  * ecx = pointer to the color table
  * edx = size of the color table
    (must be 40 bytes for future compatibility)
Format of the color table is shown in description of subfunction 3.
Returned value:
  * function does not return value
Remarks:
  * After call to this function one should redraw the screen by
    subfunction 0.
  * Table of standard colors influences only to applications,
    which receive this table obviously (by subfunction 3)
    and use it (specifying colors from it to drawing functions).
  * Table of standard colors is included in skin and is installed
    anew with skin installation (by subfunction 8).
  * Color table can be viewed/changed interactively with
    the application 'desktop'.

---------------------- Constants for registers: ----------------------
  eax - SF_STYLE_SETTINGS (48)
  ebx - SSF_SET_COLORS (2)
======================================================================
====== Function 48, subfunction 3 - get standard window colors. ======
======================================================================
Parameters:
  * eax = 48 - function number
  * ebx = 3 - subfunction number
  * ecx = pointer to the buffer with size edx bytes,
    where table will be written
  * edx = size of color table
    (must be 40 bytes for future compatibility)
Returned value:
  * function does not return value
Format of the color table:
each item is dword-value for color 0x00RRGGBB
  * +0: dword: frames - color of frame
  * +4: dword: grab - color of header
  * +8: dword: grab_button - color of button on header bar
  * +12 = +0xC: dword: grab_button_text - color of text on button
    on header bar
  * +16 = +0x10: dword: grab_text - color of text on header
  * +20 = +0x14: dword: work - color of working area
  * +24 = +0x18: dword: work_button - color of button in working area
  * +28 = +0x1C: dword: work_button_text - color of text on button
    in working area
  * +32 = +0x20: dword: work_text - color of text in working area
  * +36 = +0x24: dword: work_graph - color of graphics in working area
Remarks:
  * Structure of the color table is described in the standard
    include file 'macros.inc' as 'system_colors'; for example,
    it is possible to write:
        sc      system_colors           ; variable declaration
        ...                             ; somewhere one must call
                                        ; this function with ecx=sc
        mov     ecx, [sc.work_button_text]      ; read text color on
                                        ; buttin in working area
  * A program itself desides to use or not to use color table.
    For usage program must simply at calls to drawing functions select
    color taken from the table.
  * At change of the table of standard colors (by subfunction 2 with
    the subsequent application of changes by subfunction 0 or
    at skin set by subfunction 8) the system sends to all windows
    redraw message (the event with code 1).
  * Color table can be viewed/changed interactively with
    the application 'desktop'.

---------------------- Constants for registers: ----------------------
  eax - SF_STYLE_SETTINGS (48)
  ebx - SSF_GET_COLORS (3)
======================================================================
============ Function 48, subfunction 4 - get skin height. ===========
======================================================================
Parameters:
  * eax = 48 - function number
  * ebx = 4 - subfunction number
Returned value:
  * eax = skin height
Remarks:
  * Skin height is defined as the height of a header
    of skinned windows.
  * See also general structure of window in the description
    of function 0.

---------------------- Constants for registers: ----------------------
  eax - SF_STYLE_SETTINGS (48)
  ebx - SSF_GET_SKIN_HEIGHT (4)
======================================================================
======== Function 48, subfunction 5 - get screen working area. =======
======================================================================
Parameters:
  * eax = 48 - function number
  * ebx = 5 - subfunction number
Returned value:
  * eax = [left]*65536 + [right]
  * ebx = [top]*65536 + [bottom]
Remarks:
  * The screen working area defines position and coordinates of
    a maximized window.
  * The screen working area in view of normal work is all screen
    without taskbar ('@taskbar' application).
  * (left,top) are coordinates of the left upper corner,
    (right,bottom) are coordinates of the right lower one.
    Thus the size of working area on x axis can be calculated by
    formula right-left+1, on y axis - by formula bottom-right+1.
  * See also function 14,
    to get sizes of all screen.
  * There is a pair function to set working area - subfunction 6.

---------------------- Constants for registers: ----------------------
  eax - SF_STYLE_SETTINGS (48)
  ebx - SSF_GET_SCREEN_AREA (5)
======================================================================
======== Function 48, subfunction 6 - set screen working area. =======
======================================================================
Parameters:
  * eax = 48 - function number
  * ebx = 6 - subfunction number
  * ecx = [left]*65536 + [right]
  * edx = [top]*65536 + [bottom]
Returned value:
  * function does not return value
Remarks:
  * The screen working area defines position and coordinates of
    a maximized window.
  * This function is used only by the application '@taskbar',
    which set working area to all screen without taskbar.
  * (left,top) are coordinates of the left upper corner,
    (right,bottom) are coordinates of the right lower one.
    Thus the size of working area on x axis can be calculated by
    formula right-left+1, on y axis - by formula bottom-right+1.
  * If 'left'>='right', x-coordinate of working area is not changed.
    If 'left'<0, 'left' will not be set. If 'right' is greater than or
    equal to screen width, 'right' will not be set.
    Similarly on y axis.
  * See also function 14,
    to get sizes of all screen.
  * There is a pair function to get working area - subfunction 5.
  * This function redraws the screen automatically,
    updating coordinates and sizes of maximized windows.
    The system sends to all windows redraw message (the event 1).

---------------------- Constants for registers: ----------------------
  eax - SF_STYLE_SETTINGS (48)
  ebx - SSF_SET_SCREEN_AREA (6)
======================================================================
=========== Function 48, subfunction 7 - get skin margins. ===========
======================================================================
Returns the area of a header of a skinned window, intended for
a text of a header.
Parameters:
  * eax = 48 - function number
  * ebx = 7 - subfunction number
Returned value:
  * eax = [left]*65536 + [right]
  * ebx = [top]*65536 + [bottom]
Remarks:
  * An application decides itself to use or not to use this function.
  * It is recommended to take into account returned value
    of this function for choice of a place for drawing header text
    (by function 4) or a substitute of header text
    (at the discretion of an application).

---------------------- Constants for registers: ----------------------
  eax - SF_STYLE_SETTINGS (48)
  ebx - SSF_GET_SKIN_MARGINS (7)
======================================================================
============= Function 48, subfunction 8 - set used skin. ============
======================================================================
Parameters:
  * eax = 48 - function number
  * ebx = 8 - subfunction number
  * ecx = pointer to filename of the skin
Returned value:
  * eax = 0 - success
  * otherwise eax = file system error code; if file does not
    contain valid skin, function returns error 3
    (unknown file system).
Remarks:
  * After successful skin loading the system sends to all windows
    redraw message (the event 1).
  * At booting the system reads skin from file 'default.skn'
    on ramdisk.
  * User can change the skin statically by creating hisself
    'default.skn' or dynamically with the application 'desktop'.

---------------------- Constants for registers: ----------------------
  eax - SF_STYLE_SETTINGS (48)
  ebx - SSF_SET_SKIN (8)
======================================================================
====== Function 48, subfunction 9 - get font smoothing setting. ======
======================================================================
Parameters:
  * eax = 48 - function number
  * ebx = 9 - subfunction number
Returned value:
  * eax = 2 - subpixel, 1 - anti-aliasing, 0 - off

---------------------- Constants for registers: ----------------------
  eax - SF_STYLE_SETTINGS (48)
  ebx - SSF_GET_FONT_SMOOTH (9)
======================================================================
========== Function 48, subfunction 10 - set font smoothing. =========
======================================================================
Parameters:
  * eax = 48 - function number
  * ebx = 10 - subfunction number
  * cl  = 2 - subpixel, 1 - anti-aliasing, 0 - off

---------------------- Constants for registers: ----------------------
  eax - SF_STYLE_SETTINGS (48)
  ebx - SSF_SET_FONT_SMOOTH (10)
======================================================================
============ Function 48, subfunction 11 - get font size. ============
======================================================================
Parameters:
  * eax = 48 - function number
  * ebx = 9 - subfunction number
Returned value:
  * eax = current font height in pixels

---------------------- Constants for registers: ----------------------
  eax - SF_STYLE_SETTINGS (48)
  ebx - SSF_GET_FONT_SIZE (11)
======================================================================
============ Function 48, subfunction 12 - set font size. ============
======================================================================
Parameters:
  * eax = 48 - function number
  * ebx = 10 - subfunction number
  * cl  = new font height in pixels

---------------------- Constants for registers: ----------------------
  eax - SF_STYLE_SETTINGS (48)
  ebx - SSF_SET_FONT_SIZE (12)
======================================================================
=========== Function 49 - Advanced Power Management (APM). ===========
======================================================================
Parameters:
  * eax = 49 - function number
  * dx = number of the APM function
    (analogue of ax in APM specification)
  * bx, cx = parameters of the APM function
Returned value:
  * 16-bit registers ax, bx, cx, dx, si, di and carry flag CF
    are set according to the APM specification
  * high halves of 32-bit registers eax, ebx, ecx,
    edx, esi, edi are destroyed
Remarks:
  * APM 1.2 specification is described in the document
    "Advanced Power Management (APM) BIOS Specification"
    (Revision 1.2), available at
    http://www.microsoft.com/whdc/archive/amp_12.mspx;
    besides it is included in famous Interrupt List by Ralf Brown
    (http://www.pobox.com/~ralf/files.html,
    ftp://ftp.cs.cmu.edu/afs/cs/user/ralf/pub/).

---------------------- Constants for registers: ----------------------
  eax - SF_APM (49)
======================================================================
=================== Function 50 - set window shape. ==================
======================================================================
Normal windows have rectangular shape. This function can give to
a window any shape. The shape is given by a set of points inside
the base rectangle belonging to a window. Position and coordinates
of the base rectangle are set by function 0
and changed by function 67.

--------------------------- Set shape data ---------------------------
Parameters:
  * eax = 50 - function number
  * ebx = 0 - subfunction number
  * ecx = pointer to shape data (array of bytes 0/1)
Returned value:
  * function does not return value

-------------------------- Set shape scale ---------------------------
Parameters:
  * eax = 50 - function number
  * ebx = 1 - subfunction number
  * ecx sets a scale: each byte of data defines
    (2^scale)*(2^scale) pixels
Returned value:
  * function does not return value
Remarks:
  * Default scale is 0 (scale factor is 1). If in the shape data
    one byte corresponds to one pixel, there is no necessity
    to set scale.
  * Let's designate xsize = window width (in pixels), ysize = height;
    pay attention, that they are one pixel more than defined by
    functions 0, 67.
  * On definition of scale xsize and ysize must be divisible
    on 2^scale.
  * Byte of data on offset 'a' must be 0/1 and defines belonging
    to a window of square with the side 2^scale (if scale=0,
    this is one pixel) and coordinates of the left upper corner
    (a mod (xsize shr scale), a div (xsize shr scale))
  * Data size: (xsize shr scale)*(ysize shr scale).
  * Data must be presented in the memory and not change
    after set of shape.
  * The system views the shape data at every window redraw by
    function 0.
  * The call of subfunction 0 with NULL pointer results in return
    to the rectangular shape.

---------------------- Constants for registers: ----------------------
  eax - SF_SET_WINDOW_SHAPE (50)
======================================================================
==================== Function 51 - create thread. ====================
======================================================================
Parameters:
  * eax = 51 - function number
  * ebx = 1 - unique subfunction
  * ecx = address of thread entry point (starting eip)
  * edx = pointer to thread stack (starting esp)
Returned value:
  * eax = -1 - error (there is too many threads)
  * otherwise eax = TID - thread identifier

---------------------- Constants for registers: ----------------------
  eax - SF_CREATE_THREAD (51)
======================================================================
==================== Function 54, subfunction 0 ======================
============== Get the number of slots in the clipboard. =============
======================================================================
Parameters:
  * eax = 54 - function number
  * ebx = 0 - subfunction number
Returned value:
  * eax = slots in the clipboard
  * eax = -1 - main list area not found

---------------------- Constants for registers: ----------------------
  eax - SF_CLIPBOARD (54)
  ebx - SSF_GET_SLOT_COUNT (0)
======================================================================
==================== Function 54, subfunction 1 ======================
================= Read the data from the clipboard. ==================
======================================================================
Parameters:
  * eax = 54 - function number
  * ebx = 1 - subfunction number
  * eсx = slot number
Returned value:
  * eax = if successful - pointer to a memory with data
  * eax = 1 - error
  * eax = -1 - main list area not found
 
---------------------- Constants for registers: ----------------------
  eax - SF_CLIPBOARD (54)
  ebx - SSF_READ_CB (1)
======================================================================
==================== Function 54, subfunction 2 ======================
================= Write the data to the clipboard. ===================
======================================================================
Parameters:
  * eax = 54 - function number
  * ebx = 2 - subfunction number
  * eсx = the number of bytes to be copied
  * edx = a pointer to a buffer for data to be copied
Returned value:
  * eax = 0 - success
  * eax = 1 - error
  * eax = -1 - main list area not found

---------------------- Constants for registers: ----------------------
  eax - SF_CLIPBOARD (54)
  ebx - SSF_WRITE_CB (2)
======================================================================
===================== Function 54, subfunction 3 =====================
================ Delete the last slot in the clipboard ===============
======================================================================
Parameters:
  * eax = 54 - function number
  * ebx = 3 - subfunction number
Returned value:
  * eax = 0 - success
  * eax = 1 - error
  * eax = -1 - main list area not found

---------------------- Constants for registers: ----------------------
  eax - SF_CLIPBOARD (54)
  ebx - SSF_DEL_SLOT (3)
======================================================================
===================== Function 54, subfunction 4 =====================
===================== Alarm reset the lock buffer ====================
======================================================================
Parameters:
  * eax = 54 - function number
  * ebx = 4 - subfunction number
Returned value:
  * eax = 0 - success
  * eax = -1 - main list area not found or no blocking
Remarks:
  * Used in exceptional cases, where no responsible or killed
    application blocked the clipboard operations.

---------------------- Constants for registers: ----------------------
  eax - SF_CLIPBOARD (54)
  ebx - SSF_UNLOCK_BUFFER (4)
======================================================================
 Function 55, subfunction 55 - begin to play data on built-in speaker.
======================================================================
Parameters:
  * eax = 55 - function number
  * ebx = 55 - subfunction number
  * esi = pointer to data
Returned value:
  * eax = 0 - success
  * eax = 55 - error (speaker is off or busy)
Data is an array of items with variable length.
Format of each item is defined by first byte:
  * 0 = end of data
  * 1..0x80 = sets sound duration on 1/100 of second; sound note
    is defined by immediate value of frequency
    * following word (2 bytes) contains frequency divider;
      frequency is defined as 1193180/divider
  * 0x81 = invalid
  * 0x82..0xFF = note is defined by octave and number:
    * duration in 1/100 of second = (first byte)-0x81
    * there is one more byte;
    * (second byte)=0xFF - delay
    * otherwise it looks like a*0x10+b, where b=number of the note in
      an octave from 1 to 12, a=number of octave (beginning from 0)
Remarks:
  * Speaker play can be disabled/enabled by
    subfunction 8 of function 18.
  * Function returns control, having informed the system
    an information on request. Play itself goes independently from
    the program.
  * The data must be kept in the memory at least up to the end
    of play.

---------------------- Constants for registers: ----------------------
  eax - SF_SPEAKER_PLAY (55)
======================================================================
======================= Function 57 - PCI BIOS. ======================
======================================================================
Parameters:
  * eax = 57 - function number
  * ebp corresponds to al in PCI BIOS specification
  * other registers are set according to PCI BIOS specification
Returned value:
  * CF is undefined
  * other registers are set according to PCI BIOS specification
Remarks:
  * Many effects of this function can be also achieved with
    corresponding subfunctions of function 62.
  * The function calls PCI32 BIOS extension, documented e.g. in
    http://alpha1.dyns.net/files/PCI/bios21.pdf.
  * If BIOS does not support this extension, its behavior is emulated
    (through kernel-mode analogues of subfunctions of function 62).

---------------------- Constants for registers: ----------------------
  eax - SF_PCI_BIOS (57)
======================================================================
========== Function 60 - Inter Process Communication (IPC). ==========
======================================================================
IPC is used for message dispatching from one process/thread to
another. Previously it is necessary to agree how to interpret
the concrete message.

----------- Subfunction 1 - set the area for IPC receiving -----------
Is called by process-receiver.
Parameters:
  * eax = 60 - function number
  * ebx = 1 - subfunction number
  * ecx = pointer to the buffer
  * edx = size of the buffer
Returned value:
  * eax = 0 - always success
Format of IPC-buffer:
  * +0: dword: if nonzero, buffer is considered locked;
    lock/unlock the buffer, when you work with it and need that
    buffer data are not changed from outside (no new messages)
  * +4: dword: occupied place in the buffer (in bytes)
  * +8: first message
  * +8+n: second message
  * ...
Format of a message:
  * +0: dword: PID of sender
  * +4: dword: message length (not including this header)
  * +8: n*byte: message data

------------------ Subfunction 2 - send IPC message ------------------
Is called by process-sender.
Parameters:
  * eax = 60 - function number
  * ebx = 2 - subfunction number
  * ecx = PID of receiver
  * edx = pointer to the message data
  * esi = message length (in bytes)
Returned value:
  * eax = 0 - success
  * eax = 1 - the receiver has not defined buffer for IPC messages
    (can be, still have no time,
    and can be, this is not right process)
  * eax = 2 - the receiver has blocked IPC-buffer; try to wait a bit
  * eax = 3 - overflow of IPC-buffer of the receiver
  * eax = 4 - process/thread with such PID does not exist
Remarks:
  * Immediately after writing of IPC-message to the buffer the system
    sends to the receiver the event with code 7 (see event codes).

---------------------- Constants for registers: ----------------------
  eax - SF_IPC (60)
  ebx - SSF_SET_AREA (1), SSF_SEND_MESSAGE (2)
======================================================================
==== Function 61 - get parameters for the direct graphics access. ====
======================================================================
The data of the graphics screen (the memory area which displays
screen contents) are accessible to a program directly, without
any system calls, through the selector gs:
        mov     eax, [gs:0]
places in eax the first dword of the buffer, which contains
information on color of the left upper point (and, possibly, colors
of several following).
        mov     [gs:0], eax
by work in VESA modes with LFB sets color of the left upper point
(and, possibly, colors of several following).
To interpret the data of graphics screen program needs to know
some parameters, returning by this function.
Remarks:
  * Graphics parameters changes very seldom at work,
    namely, only in cases, when user works with the application VRR.
  * At videomode change the system redraws all windows (event
    with code 1) and redraws the background (event 5).
    Same events occur in other cases too, which meet much more often,
    than videomode change.
  * By operation in videomodes with LFB the selector gs points to
    LFB itself, so reading/writing on gs result directly in
    change of screen contents. By operation in videomodes without
    LFB gs points to some data area in the kernel, and all functions
    of screen output fulfil honesty double operation on writing
    directly to the screen and writing to this buffer. In result
    at reading contents of this buffer the results correspond to
    screen contents (with, generally speaking, large color
    resolution), and writing is ignored.
    One exception is the mode 320*200, for which main loop of the
    system thread updates the screen according to mouse movements.

------------------------- Screen resolution --------------------------
Parameters:
  * eax = 61 - function number
  * ebx = 1 - subfunction number
Returned value:
  * eax = [resolution on x axis]*65536 + [resolution on y axis]
Remarks:
  * One can use function 14 paying attention that
    it returns sizes on 1 pixel less. It is fully equivalent way.

---------------------- Number of bits per pixel ----------------------
Parameters:
  * eax = 61 - function number
  * ebx = 2 - subfunction number
Returned value:
  * eax = number of bits per pixel (24 or 32)

-------------------- Number of bytes per scanline --------------------
Parameters:
  * eax = 61 - function number
  * ebx = 3 - subfunction number
Returned value:
  * eax = number of bytes occupied by one scanline
    (horizontal line on the screen)

---------------------- Constants for registers: ----------------------
  eax - SF_GET_GRAPHICAL_PARAMS (61)
  ebx - SSF_SCREEN_SIZE (1), SSF_BITS_PER_PIXEL (2),
    SSF_BYTES_PER_LINE (3)
======================================================================
===== Function 62, subfunction 0 - get version of PCI-interface. =====
======================================================================
Parameters:
  * eax = 62 - function number
  * bl = 0 - subfunction number
Returned value:
  * eax = -1 - PCI access is disabled; otherwise
  * ah.al = version of PCI-interface (ah=version, al=subversion)
  * high word of eax is zeroed
Remarks:
  * Previously low-level access to PCI for applications must be
    enabled by subfunction 12 of function 21.
  * If PCI BIOS is not supported, the value of ax is undefined.

---------------------- Constants for registers: ----------------------
  eax - SF_PCI (62)
  ebx - SSF_GET_VERSION (0)
======================================================================
==== Function 62, subfunction 1 - get number of the last PCI-bus. ====
======================================================================
Parameters:
  * eax = 62 - function number
  * bl = 1 - subfunction number
Returned value:
  * eax = -1 - access to PCI is disabled; otherwise
  * al = number of the last PCI-bus; other bytes of eax are destroyed
Remarks:
  * Previously low-level access to PCI for applications must be
    enabled by subfunction 12 of function 21.
  * If PCI BIOS is not supported, the value of ax is undefined.

---------------------- Constants for registers: ----------------------
  eax - SF_PCI (62)
  ebx - SSF_GET_LAST_BUS (1)
======================================================================
===================== Function 62, subfunction 2 =====================
===== Get mechanism of addressing to the PCI configuration space. ====
======================================================================
Parameters:
  * eax = 62 - function number
  * bl = 2 - subfunction number
Returned value:
  * eax = -1 - access to PCI is disabled; otherwise
  * al = mechanism (1 or 2); other bytes of eax are destroyed
Remarks:
  * Previously low-level access to PCI for applications must be
    enabled by subfunction 12 of function 21.
  * Addressing mechanism is selected depending on
    equipment characteristics.
  * Subfunctions of read and write work automatically
    with the selected mechanism.

---------------------- Constants for registers: ----------------------
  eax - SF_PCI (62)
  ebx - SSF_GET_ADRR_MODE (2)
======================================================================
======== Function 62, subfunctions 4,5,6 - read PCI-register. ========
======================================================================
Parameters:
  * eax = 62 - function number
  * bl = 4 - read byte
  * bl = 5 - read word
  * bl = 6 - read dword
  * bh = number of PCI-bus
  * ch = dddddfff, where ddddd = number of the device on the bus,
    fff = function number of device
  * cl = number of register (must be even for bl=5,
    divisible by 4 for bl=6)
Returned value:
  * eax = -1 - error (access to PCI is disabled or parameters
    are not supported); otherwise
  * al/ax/eax (depending on requested size) contains the data;
    the other part of register eax is destroyed
Remarks:
  * Previously low-level access to PCI for applications must be
    enabled by subfunction 12 of function 21.
  * Access mechanism 2 supports only 16 devices on a bus and ignores
    function number. To get access mechanism use subfunction 2.
  * Some registers are standard and exist for all devices, some are
    defined by the concrete device. The list of registers of the
    first type can be found e.g. in famous
    Interrupt List by Ralf Brown
    (http://www.pobox.com/~ralf/files.html,
    ftp://ftp.cs.cmu.edu/afs/cs/user/ralf/pub/);
    registers of the second type must be listed
    in the device documentation.

---------------------- Constants for registers: ----------------------
  eax - SF_PCI (62)
  ebx - SSF_READ_BYTE (4), SSF_READ_WORD (5), SSF_READ_DWORD (6)
======================================================================
====== Function 62, subfunctions 8,9,10 - write to PCI-register. =====
======================================================================
Parameters:
  * eax = 62 - function number
  * bl = 8 - write byte
  * bl = 9 - write word
  * bl = 10 - write dword
  * bh = number of PCI-bus
  * ch = dddddfff, where ddddd = number of the device on the bus,
    fff = function number of device
  * cl = number of register (must be even for bl=9,
    divisible by 4 for bl=10)
  * dl/dx/edx (depending on requested size) contatins
    the data to write
Returned value:
  * eax = -1 - error (access to PCI is disabled or parameters
    are not supported)
  * eax = 0 - success
Remarks:
  * Previously low-level access to PCI for applications must be
    enabled by subfunction 12 of function 21.
  * Access mechanism 2 supports only 16 devices on a bus and ignores
    function number. To get access mechanism use subfunction 2.
  * Some registers are standard and exist for all devices, some are
    defined by the concrete device. The list of registers of the
    first type can be found e.g. in famous Interrupt List by
    Ralf Brown; registers of the second type must be listed
    in the device documentation.

---------------------- Constants for registers: ----------------------
  eax - SF_PCI (62)
  ebx - SSF_WRITE_BYTE (8), SSF_WRITE_WORD (9), SSF_WRITE_DWORD (10)
======================================================================
============== Function 63 - work with the debug board. ==============
======================================================================
The debug board is the global system buffer (with the size
1024 bytes), to which any program can write (generally speaking,
arbitrary) data and from which other program can read these data.
By the agreement written data are text strings interpreted as
debug messages on a course of program execution. The kernel in
some situations also writes to the debug board information on
execution of some functions; by the agreement kernel messages
begins from the prefix "K : ".
For view of the debug board the application 'board' was created,
which reads data from the buffer and displays them in its window.
'board' interpretes the sequence of codes 13,10 as newline.
A character with null code in an end of line is not necessary,
but also does not prevent.
Because debugger has been written, the value of the debug board
has decreased, as debugger allows to inspect completely a course of
program execution without any efforts from the direction of program
itself. Nevertheless in some cases the debug board is still useful.

----------------------------- Write byte -----------------------------
Parameters:
  * eax = 63 - function number
  * ebx = 1 - subfunction number
  * cl = data byte
Returned value:
  * function does not return value
Remarks:
  * Byte is written to the buffer. Buffer size is 512 bytes.
    At buffer overflow all obtained data are lost.
  * For output to the debug board of more complicated objects
    (strings, numbers) it is enough to call this function in cycle.
    It is possible not to write the appropriate code manually and use
    file 'debug.inc', which is included into the distributive.

----------------------------- Read byte ------------------------------
Takes away byte from the buffer.
Parameters:
  * eax = 63 - function number
  * ebx = 2 - subfunction number
Returned value:
  * eax = ebx = 0 - the buffer is empty
  * eax = byte, ebx = 1 - byte was successfully read

---------------------- Constants for registers: ----------------------
  eax - SF_BOARD (63)
  ebx - SSF_DEBUG_WRITE (1), SSF_DEBUG_READ (2)
======================================================================
============== Function 64 - resize application memory. ==============
======================================================================
Parameters:
  * eax = 64 - function number
  * ebx = 1 - unique subfunction
  * ecx = new memory size
Returned value:
  * eax = 0 - success
  * eax = 1 - not enough memory
Remarks:
  * There is another way to dynamically allocate/free memory -
    subfunctions 11, 12, 13 of function 68.
  * The function cannot be used together with 68.11, 68.12, 68.13.
    The function call will be ignored after creation of process heap
    with function 68.11.

---------------------- Constants for registers: ----------------------
  eax - SF_MEMORY_RESIZE (64)
======================================================================
======== Function 65 - draw image with palette in the window. ========
======================================================================
Parameters:
  * eax = 65 - function number
  * ebx = pointer to the image
  * ecx = [size on axis x]*65536 + [size on axis y]
  * edx = [coordinate on axis x]*65536 + [coordinate on axis y]
  * esi = number of bits per pixel, must be 1,2,4,8,9,15,16,24 or 32;
  * edi = pointer to palette (2 to the power esi colors 0x00RRGGBB);
          ignored when esi > 8
  * ebp = offset of next row data relative to previous row data
Returned value:
  * function does not return value
Remarks:
  * Coordinates of the image are coordinates of the upper left corner
    of the image relative to the window.
  * Format of image with 1 bit per pixel: each byte of image
    (possibly excluding last bytes in rows), contains information on
    the color of 8 pixels, MSB corresponds to first pixel.
  * Format of image with 2 bits per pixel: each byte of image
    (possibly excluding last bytes in rows), contains information on
    the color of 4 pixels, two MSBs correspond to first pixel.
  * Format of image with 4 bits per pixel: each byte of image
    excluding last bytes in rows (if width is odd) contains
    information on the color of 2 pixels, high-order tetrad
    corresponds to first pixel.
  * Format of image with 8 bits per pixel: each byte of image is
    index in the palette.
  * Format of image with 9 bits per pixel: array of one byte values;
    each byte (8 bit) represents the intensity of gray for one pixel;
    this format is equal to 8bpp without palette.
  * Format of image with 15 bits per pixel: the color of each pixel
    is coded as (bit representation) 0RRRRRGGGGGBBBBB - 5 bits per
    each color.
  * Format of image with 16 bits per pixel: the color of each pixel
    is coded as RRRRRGGGGGGBBBBB (5+6+5).
  * Format of image with 24 bits per pixel: the color of each pixel
    is coded as 3 bytes - sequentially blue, green, red components.
  * Format of image with 32 bits per pixel: similar to 24, but
    one additional ignored byte is present.
  * The call to function 7 is equivalent to call to this function
    with esi=24, ebp=0.

---------------------- Constants for registers: ----------------------
  eax - SF_PUT_IMAGE_EXT (65)
======================================================================
================== Function 66 - work with keyboard. =================
======================================================================
The input mode influences results of reading keys by function 2.
When a program loads, ASCII input mode is set for it.

-------------- Subfunction 1 - set keyboard input mode. --------------
Parameters:
  * eax = 66 - function number
  * ebx = 1 - subfunction number
  * ecx = mode:
    * 0 = normal (ASCII-characters)
    * 1 = scancodes
Returned value:
  * function does not return value

-------------- Subfunction 2 - get keyboard input mode. --------------
Parameters:
  * eax = 66 - function number
  * ebx = 2 - subfunction number
Returned value:
  * eax = current mode

------------ Subfunction 3 - get status of control keys. -------------
Parameters:
  * eax = 66 - function number
  * ebx = 3 - subfunction number
Returned value:
  * eax = bit mask:
  * bit 0  (mask 1): left Shift is pressed
  * bit 1  (mask 2): right Shift is pressed
  * bit 2  (mask 4): left Ctrl is pressed
  * bit 3  (mask 8): right Ctrl is pressed
  * bit 4  (mask 0x10): left Alt is pressed
  * bit 5  (mask 0x20): right Alt is pressed
  * bit 6  (mask 0x40): CapsLock is on
  * bit 7  (mask 0x80): NumLock is on
  * bit 8  (mask 0x100): ScrollLock is on
  * bit 9  (mask 0x200): left Win is pressed
  * bit 10 (mask 0x400): right Win is pressed
  * other bits are cleared

-------------- Subfunction 4 - set system-wide hotkey. ---------------
When hotkey is pressed, the system notifies only those applications,
which have installed it; the active application (which receives
all normal input) does not receive such keys.
The notification consists in sending event with the code 2.
Reading hotkey is the same as reading normal key - by function 2.
Parameters:
  * eax = 66 - function number
  * ebx = 4 - subfunction number
  * cl determines key scancode;
    use cl=0 to give combinations such as Ctrl+Shift
  * edx = 0xXYZ determines possible states of control keys:
    * Z (low 4 bits) determines state of LShift and RShift:
      * 0 = no key must be pressed;
      * 1 = exactly one key must be pressed;
      * 2 = both keys must be pressed;
      * 3 = must be pressed LShift, but not RShift;
      * 4 = must be pressed RShift, but not LShift
    * Y - similar for LCtrl and RCtrl;
    * X - similar for LAlt and RAlt
Returned value:
  * eax=0 - success
  * eax=1 - too mant hotkeys (maximum 256 are allowed)
Remarks:
  * Hotkey can work either at pressing or at release. Release
    scancode of a key is more on 128 than pressing scancode
    (i.e. high bit is set).
  * Several applications can set the same combination;
    all such applications will be informed on pressing
    such combination.

-------------- Subfunction 5 - delete installed hotkey. --------------
Parameters:
  * eax = 66 - function number
  * ebx = 5 - subfunction number
  * cl = scancode of key and edx = 0xXYZ the same as in subfunction 4
Returned value:
  * eax = 0 - success
  * eax = 1 - there is no such hotkey
Remarks:
  * When a process/thread terminates, all hotkey installed by it are
    deleted.
  * The call to this subfunction does not affect other applications.
    If other application has defined the same combination, it will
    still receive notices.

--------------- Subfunction 6 - block the normal input. --------------
Parameters:
  * eax = 66 - function number
  * ebx = 6 - subfunction number
Returned value:
  * function does not return value
Remarks:
  * Blocking the normal keyboard input for installed hotkeys
  * To emulate a mouse via the keyboard, the application MOUSEMUL

------------ Subfunction 7 - unlock the normal input. ----------------
Parameters:
  * eax = 66 - function number
  * ebx = 7 - subfunction number
Returned value:
  * function does not return value
Remarks:
  * Unlocking the results of the f. 66.6
  * To emulate a mouse via the keyboard, the application MOUSEMUL

---------------------- Constants for registers: ----------------------
  eax - SF_KEYBOARD (66)
  ebx - SSF_SET_INPUT_MODE (1), SSF_GET_INPUT_MODE (2),
    SSF_GET_CONTROL_KEYS (3), SSF_SET_SYS_HOTKEY (4),
    SSF_DEL_SYS_HOTKEY (5),  SSF_LOCK_INPUT (6), SSF_UNLOCK_INPUT (7)
======================================================================
========= Function 67 - change position/sizes of the window. =========
======================================================================
Parameters:
  * eax = 67 - function number
  * ebx = new x-coordinate of the window
  * ecx = new y-coordinate of the window
  * edx = new x-size of the window
  * esi = new y-size of the window
Returned value:
  * function does not return value
Remarks:
  * The value -1 for a parameter means "do not change"; e.g. to move
    the window without resizing it is possible to specify edx=esi=-1.
  * Previously the window must be defined by function 0.
    It sets initial coordinates and sizes of the window.
  * Sizes of the window are understood in sense of function 0,
    that is one pixel less than real sizes.
  * The function call for maximized windows is simply ignored.
  * For windows of appropriate styles position and/or sizes can be
    changed by user; current position and sizes can be obtained by
    call to function 9.
  * The function sends to the window redraw event (with the code 1).

---------------------- Constants for registers: ----------------------
  eax - SF_CHANGE_WINDOW (67)
======================================================================
====== Function 68, subfunction 0 - get the task switch counter. =====
======================================================================
Parameters:
  * eax = 68 - function number
  * ebx = 0 - subfunction number
Returned value:
  * eax = number of task switches from the system booting
    (modulo 2^32)

---------------------- Constants for registers: ----------------------
  eax - SF_SYS_MISC (68)
  ebx - SSF_GET_TASK_SWITCH_COUNT (0)
======================================================================
======= Function 68, subfunction 1 - switch to the next thread. ======
======================================================================
The function completes the current time slice allocated to the
thread and switches to the next. (Which thread in which process
will be next, is unpredictable). Later, when execution queue
will reach the current thread, execution will be continued.
Parameters:
  * eax = 68 - function number
  * ebx = 1 - subfunction number
Returned value:
  * function does not return value

---------------------- Constants for registers: ----------------------
  eax - SF_SYS_MISC (68)
  ebx - SSF_SWITCH_TASK (1)
======================================================================
============= Function 68, subfunction 2 - cache + rdpmc. ============
======================================================================
Parameters:
  * eax = 68 - function number
  * ebx = 2 - subfunction number
  * ecx = required action:
    * ecx = 0 - enable instruction 'rdpmc'
      (ReaD Performance-Monitoring Counters) for applications
    * ecx = 1 - find out whether cache is disabled/enabled
    * ecx = 2 - enable cache
    * ecx = 3 - disable cache
Returned value:
  * for ecx=0:
    * eax = the value of cr4
  * for ecx=1:
    * eax = (cr0 and 0x60000000):
    * eax = 0 - cache is on
    * eax <> 0 - cache is off
  * for ecx=2 and ecx=3:
    * function does not return value

---------------------- Constants for registers: ----------------------
  eax - SF_SYS_MISC (68)
  ebx - SSF_PERFORMANCE (2)
  ecx - SSSF_ALLOW_RDPMC (0), SSSF_CACHE_STATUS (1),
    SSSF_CACHE_ON (2), SSSF_CACHE_OFF (3)
======================================================================
=========== Function 68, subfunction 3 - read MSR-register. ==========
======================================================================
MSR = Model Specific Register; the complete list of MSR-registers
of a processor is included to the documentation on it (for example,
IA-32 Intel Architecture Software Developer's Manual,
Volume 3, Appendix B); each processor family has its own subset
of the MSR-registers.
Parameters:
  * eax = 68 - function number
  * ebx = 3 - subfunction number
  * ecx is ignored
  * edx = MSR address
Returned value:
  * ebx:eax = high:low dword of the result
Remarks:
  * If ecx contains nonexistent or not implemented for this processor
    MSR, processor will generate an exception in the kernel, which
    will kill the thread.
  * Previously it is necessary to check, whether MSRs are supported
    as a whole, with the instruction 'cpuid'. Otherwise processor
    will generate other exception in the kernel, which will anyway
    kill the thread.

---------------------- Constants for registers: ----------------------
  eax - SF_SYS_MISC (68)
  ebx - SSF_READ_MSR (3)
======================================================================
========= Function 68, subfunction 4 - write to MSR-register. ========
======================================================================
MSR = Model Specific Register; the complete list of MSR-registers
of a processor is included to the documentation on it (for example,
IA-32 Intel Architecture Software Developer's Manual,
Volume 3, Appendix B); each processor family has its own subset
of the MSR-registers.
Parameters:
  * eax = 68 - function number
  * ebx = 4 - subfunction number
  * ecx is ignored
  * edx = MSR address
  * esi:edi = high:low dword
Returned value:
  * function does not return value
Remarks:
  * If ecx contains nonexistent or not implemented for this processor
    MSR, processor will generate an exception in the kernel, which
    will kill the thread.
  * Previously it is necessary to check, whether MSRs are supported
    as a whole, with the instruction 'cpuid'. Otherwise processor
    will generate other exception in the kernel, which will anyway
    kill the thread.

---------------------- Constants for registers: ----------------------
  eax - SF_SYS_MISC (68)
  ebx - SSF_WRITE_MSR (4)
======================================================================
======= Function 68, subfunction 11 - initialize process heap. =======
======================================================================
Parameters:
  * eax = 68 - function number
  * ebx = 11 - subfunction number
Returned value:
  * eax = 0 - failed
  * otherwise size of created heap
Remarks:
  * The function call initializes heap, from which one can in future
    allocate and free memory blocks with subfunctions 12 and 13.
    Heap size is equal to total amount of free application memory.
  * The second function call from the same process results in
    returning the size of the existing heap.
  * After creation of the heap calls to function 64 will be ignored.

---------------------- Constants for registers: ----------------------
  eax - SF_SYS_MISC (68)
  ebx - SSF_HEAP_INIT (11)
======================================================================
======== Function 68, subfunction 12 - allocate memory block. ========
======================================================================
Parameters:
  * eax = 68 - function number
  * ebx = 12 - subfunction number
  * ecx = required size in bytes
Returned value:
  * eax = pointer to the allocated block
Remarks:
  * Before this call one must initialize process heap by call to
    subfunction 11.
  * The function allocates an integer number of pages (4 Kb) in such
    way that the real size of allocated block is more than or equal to
    requested size.

---------------------- Constants for registers: ----------------------
  eax - SF_SYS_MISC (68)
  ebx - SSF_MEM_ALLOC (12)
======================================================================
========== Function 68, subfunction 13 - free memory block. ==========
======================================================================
Parameters:
  * eax = 68 - function number
  * ebx = 13 - subfunction number
  * ecx = pointer to the memory block
Returned value:
  * eax = 1 - success
  * eax = 0 - failed
Remarks:
  * The memory block must have been allocated by subfunction 12
    or subfunction 20.

---------------------- Constants for registers: ----------------------
  eax - SF_SYS_MISC (68)
  ebx - SSF_MEM_FREE (13)
======================================================================
===================== Function 68, subfunction 14 ====================
============ Wait for signal from another program/driver. ============
======================================================================
Parameters:
  * eax = 68 - function number
  * ebx = 14 - subfunction number
  * ecx = pointer to the buffer for information (24 bytes)
Returned value:
  * buffer pointed to by ecx contains the following information:
    * +0: dword: identifier for following data of signal
    * +4: dword: data of signal (20 bytes), format of which is defined
          by the first dword

---------------------- Constants for registers: ----------------------
  eax - SF_SYS_MISC (68)
  ebx - SSF_WAIT_SIGNAL (14)
======================================================================
============= Function 68, subfunction 16 - load driver. =============
======================================================================
Parameters:
  * eax = 68 - function number
  * ebx = 16 - subfunction number
  * ecx = pointer to ASCIIZ-string with driver name
Returned value:
  * eax = 0 - failed
  * otherwise eax = driver handle
Remarks:
  * If the driver was not loaded yet, it is loaded;
    if the driver was loaded yet, nothing happens.
  * Driver name is case-sensitive.
    Maximum length of the name is 16 characters, including
    terminating null character, the rest is ignored.
  * Driver ABC is loaded from file /rd/1/drivers/ABC.obj.

---------------------- Constants for registers: ----------------------
  eax - SF_SYS_MISC (68)
  ebx - SSF_LOAD_DRIVER (16)
======================================================================
============ Function 68, subfunction 17 - driver control. ===========
======================================================================
Parameters:
  * eax = 68 - function number
  * ebx = 17 - subfunction number
  * ecx = pointer to the control structure:
    * +0: dword: handle of driver
    * +4: dword: code of driver function
    * +8: dword: pointer to input data
    * +12 = +0xC: dword: size of input data
    * +16 = +0x10: dword: pointer to output data
    * +20 = +0x14: dword: size of output data
Returned value:
  * eax = determined by driver
Remarks:
  * Function codes and the structure of input/output data
    are defined by driver.
  * Previously one must obtain driver handle by subfunction 16.

---------------------- Constants for registers: ----------------------
  eax - SF_SYS_MISC (68)
  ebx - SSF_CONTROL_DRIVER (17)
======================================================================
=============== Function 68, subfunction 19 - load DLL. ==============
======================================================================
Parameters:
  * eax = 68 - function number
  * ebx = 19 - subfunction number
  * ecx = pointer to ASCIIZ-string with the full path to DLL
Returned value:
  * eax = 0 - failed
  * otherwise eax = pointer to DLL export table
Remarks:
  * Export table is an array of structures of 2 dword's, terminated
    by zero. The first dword in structure points to function name,
    the second dword contains address of function.

---------------------- Constants for registers: ----------------------
  eax - SF_SYS_MISC (68)
  ebx - SSF_LOAD_DLL (19)
======================================================================
======= Function 68, subfunction 20 - reallocate memory block. =======
======================================================================
Parameters:
  * eax = 68 - function number
  * ebx = 20 - subfunction number
  * ecx = new size in bytes
  * edx = pointer to already allocated block
Returned value:
  * eax = pointer to the reallocated block, 0 = error
Remarks:
  * Before this call one must initialize process heap by call to
    subfunction 11.
  * The function allocates an integer number of pages (4 Kb) in such
    way that the real size of allocated block is more than or equal to
    requested size.
  * If edx=0, the function call is equivalent to memory allocation
    with subfunction 12. Otherwise the block at edx
    must be allocated earlier with subfunction 12 or this subfunction.
  * If ecx=0, the function frees memory block at edx and returns 0.
  * The contents of the block are unchanged up to the shorter of
    the new and old sizes.

---------------------- Constants for registers: ----------------------
  eax - SF_SYS_MISC (68)
  ebx - SSF_MEM_REALLOC (20)
======================================================================
=========== Function 68, subfunction 21 - load driver PE. ============
======================================================================
Parameters:
  * eax = 68 - function number
  * ebx = 21 - subfunction number
  * ecx = pointer to ASCIIZ-string with driver name
  * edx = pointer to command line
Returned value:
  * eax = 0 - failed
  * otherwise eax = driver handle
Remarks:
  * If the driver was not loaded yet, it is loaded;
    if the driver was loaded yet, nothing happens.

---------------------- Constants for registers: ----------------------
  eax - SF_SYS_MISC (68)
  ebx - SSF_LOAD_DRIVER_PE (21)
======================================================================
======== Function 68, subfunction 22 - open named memory area. =======
======================================================================
Parameters:
  * eax = 68 - function number
  * ebx = 22 - subfunction number
  * ecx = area name. Maximum of 31 characters with terminating zero
  * edx = area size in bytes for SHM_CREATE and SHM_OPEN_ALWAYS
  * esi = flags for open and access:
    * SHM_OPEN        = 0x00 - open existing memory area. If an area
                          with such name does not exist, the function
                          will return error code 5.
    * SHM_OPEN_ALWAYS = 0x04 - open existing or create new
                          memory area.
    * SHM_CREATE      = 0x08 - create new memory area. If an area
                          with such name already exists, the function
                          will return error code 10.
    * SHM_READ        = 0x00 - only read access
    * SHM_WRITE       = 0x01 - read and write access
Returned value:
  * eax = pointer to memory area, 0 if error has occured
  * if new area is created (SHM_CREATE or SHM_OPEN_ALWAYS):
    edx = 0 - success, otherwise - error code
  * if existing area is opened (SHM_OPEN or SHM_OPEN_ALWAYS):
    edx = error code (if eax=0) or area size in bytes
Error codes:
  * E_NOTFOUND = 5
  * E_ACCESS = 10
  * E_NOMEM = 30
  * E_PARAM = 33
Remarks:
  * Before this call one must initialize process heap by call to
    subfunction 11.
  * If a new area is created, access flags set maximal rights
    for other processes. An attempt from other process to open
    with denied rights will fail with error code E_ACCESS.
  * The process which has created an area always has write access.

---------------------- Constants for registers: ----------------------
  eax - SF_SYS_MISC (68)
  ebx - SSF_MEM_OPEN (22)
======================================================================
======= Function 68, subfunction 23 - close named memory area. =======
======================================================================
Parameters:
  * eax = 68 - function number
  * ebx = 23 - subfunction number
  * ecx = area name. Maximum of 31 characters with terminating zero
Returned value:
  * eax destroyed
Remarks:
  * A memory area is physically freed (with deleting all data and
    freeing physical memory), when all threads which have opened
    this area will close it.
  * When thread is terminating, all opened by it areas are closed.

---------------------- Constants for registers: ----------------------
  eax - SF_SYS_MISC (68)
  ebx - SSF_MEM_CLOSE (23)
======================================================================
======== Function 68, subfunction 24 - set exception handler. ========
======================================================================
Parameters:
  * eax = 68 - function number
  * ebx = 24 - subfunction number
  * ecx = address of the new exception handler
  * edx = the mask of handled exceptions
Returned value:
  * eax = address of the old exception handler (0, if it was not set)
  * ebx = the old mask of handled exceptions
Remarks:
  * Bit number in mask of exceptions corresponds to exception number
    in CPU-specification (Intel-PC). For example, FPU exceptions have
    number 16 (#MF), and SSE exceptions - 19 (#XF).
  * The current implementation ignores the inquiry for hook of 7
    exception - the system handles #NM by its own.
  * The exception handler is called with exception number as first
    (and only) stack parameter. So, correct exit from the handler is
    RET 4. It returns to the instruction, that caused the exception,
    for faults, and to the next instruction for traps (see
    classification of exceptions in CPU specification).
  * When user handler receives control, the corresponding bit in
    the exception mask is cleared. Raising this exception
    in consequence leads to default handling, that is,
    terminating the application in absence of debugger or
    suspend with notification of debugger otherwise.
  * After user handler completes critical operations, it can set
    the corresponding bit in the exception mask with subfunction 25.
    Also user handler is responsible for clearing exceptions flags in
    FPU and/or SSE.

---------------------- Constants for registers: ----------------------
  eax - SF_SYS_MISC (68)
  ebx - SSF_SET_EXCEPTION_HANDLER (24)
======================================================================
======== Function 68, subfunction 25 - set exception activity ========
======================================================================
Parameters:
  * eax = 68 - function number
  * ebx = 25 - subfunction number
  * ecx = signal number
  * edx = value of activity (0/1)
Returned value:
  * eax = -1 - invalid signal number
  * otherwise eax = old value of activity for this signal (0/1)
Remarks:
  * In current implementation only mask for user excepton handler,
    which has been previously set by subfunction 24,
    is changed. Signal number corresponds to exception number.

---------------------- Constants for registers: ----------------------
  eax - SF_SYS_MISC (68)
  ebx - SSF_SET_EXCEPTION_STATE (25)
======================================================================
====== Function 68, subfunction 26 - release memory pages ============
======================================================================
Parameters:
  * eax = 68 - function number
  * ebx = 26 - subfunction number
  * ecx = pointer to the memory block, allocated by subfunction 12
  * edx = offset from the block beginnings
  * esi = the size of the region of memory to release, in bytes
Remarks:
  * function release range of pages from ecx+edx to ecx+edx+esi
    and set virtual memory into reserved state.

---------------------- Constants for registers: ----------------------
  eax - SF_SYS_MISC (68)
  ebx - SSF_MEM_FREE_EXT (26)
======================================================================
========== Function 68, subfunction 27 - load file ===================
======================================================================
Parameters:
  * eax = 68 - function number
  * ebx = 27 - subfunction number
  * ecx = pointer to ASCIIZ-string with the filename
Returned value:
  * eax = pointer to the loaded file, or zero
  * edx = size of the loaded file, or zero
Remarks:
  * function loads file and unpacks, if necessary

---------------------- Constants for registers: ----------------------
  eax - SF_SYS_MISC (68)
  ebx - SSF_LOAD_FILE (27)
======================================================================
====================== Function 69 - debugging. ======================
======================================================================
A process can load other process as debugged by set of corresponding
bit by call to subfunction 7 of function 70.
A process can have only one debugger; one process can debug some
others. The system notifies debugger on events occuring with
debugged process. Messages are written to the buffer defined by
subfunction 0.
Format of a message:
  * +0: dword: message code
  * +4: dword: PID of debugged process
  * +8: there can be additional data depending on message code
Message codes:
  * 1 = exception
    * in addition dword-number of the exception is given
    * process is suspended
  * 2 = process has terminated
    * comes at any termination: both through the system function -1,
      and at "murder" by any other process (including debugger itself)
  * 3 = debug exception int 1 = #DB
    * in addition dword-image of the register DR6 is given:
      * bits 0-3: condition of the corresponding breakpoint (set by
        subfunction 9) is satisfied
      * bit 14: exception has occured because of the trace mode
        (flag TF is set TF)
    * process is suspended
When debugger terminates, all debugged processes are killed.
If debugger does not want this, it must previously detach by
subfunction 3.

All subfunctions are applicable only to processes/threads started
from the current by function 70 with set debugging flag.
Debugging of multithreaded programs is not supported yet.
The full list of subfunctions:
  * subfunction 0 - define data area for debug messages
  * subfunction 1 - get contents of registers of debugged thread
  * subfunction 2 - set contents of registers of debugged thread
  * subfunction 3 - detach from debugged process
  * subfunction 4 - suspend debugged thread
  * subfunction 5 - resume debugged thread
  * subfunction 6 - read from the memory of debugged process
  * subfunction 7 - write to the memory of debugged process
  * subfunction 8 - terminate debugged thread
  * subfunction 9 - set/clear hardware breakpoint

---------------------- Constants for registers: ----------------------
  eax - SF_DEBUG (69)
  ebx - SSF_SET_MESSAGE_AREA (0), SSF_GET_REGISTERS (1),
    SSF_SET_REGISTERS (2), SSF_DETACH (3), SSF_SUSPEND (4),
    SSF_RESUME (5), SSF_READ_MEMORY (6), SSF_WRITE_MEMORY (7),
    SSF_TERMINATE (8), SSF_DEFINE_BREAKPOINT (9)
======================================================================
= Function 69, subfunction 0 - define data area fror debug messages. =
======================================================================
Parameters:
  * eax = 69 - function number
  * ebx = 0 - subfunction number
  * ecx = pointer
Format of data area:
  * +0: dword: N = buffer size (not including this header)
  * +4: dword: occupied place
  * +8: N*byte: buffer
Returned value:
  * function does not return value
Remarks:
  * If the size field is negative, the buffer is considered locked
    and at arrival of new message the system will wait.
    For synchronization frame all work with the buffer by operations
    lock/unlock
        neg     [bufsize]
  * Data in the buffer are considered as array of items with variable
    length - messages. Format of a message is explained in
    general description.

---------------------- Constants for registers: ----------------------
  eax - SF_DEBUG (69)
  ebx - SSF_SET_MESSAGE_AREA (0)
======================================================================
===================== Function 69, subfunction 1 =====================
============ Get contents of registers of debugged thread. ===========
======================================================================
Parameters:
  * eax = 69 - function number
  * ebx = 1 - subfunction number
  * ecx = thread identifier
  * edx = size of context structure, must be 0x28=40 bytes
  * esi = pointer to context structure
Returned value:
  * function does not return value
Format of context structure: (FPU is not supported yet)
  * +0: dword: eip
  * +4: dword: eflags
  * +8: dword: eax
  * +12 = +0xC: dword: ecx
  * +16 = +0x10: dword: edx
  * +20 = +0x14: dword: ebx
  * +24 = +0x18: dword: esp
  * +28 = +0x1C: dword: ebp
  * +32 = +0x20: dword: esi
  * +36 = +0x24: dword: edi
Remarks:
  * If the thread executes code of ring-0, the function returns
    contents of registers of ring-3.
  * Process must be loaded for debugging (as is shown in
    general description).

---------------------- Constants for registers: ----------------------
  eax - SF_DEBUG (69)
  ebx - SSF_GET_REGISTERS (1)
======================================================================
===================== Function 69, subfunction 2 =====================
============ Set contents of registers of debugged thread. ===========
======================================================================
Parameters:
  * eax = 69 - function number
  * ebx = 2 - subfunction number
  * ecx = thread identifier
  * edx = size of context structure, must be 0x28=40 bytes
Returned value:
  * function does not return value
Format of context structure is shown in the description of
subfunction 1.
Remarks:
  * If the thread executes code of ring-0, the function returns
    contents of registers of ring-3.
  * Process must be loaded for debugging (as is shown in
    general description).

---------------------- Constants for registers: ----------------------
  eax - SF_DEBUG (69)
  ebx - SSF_SET_REGISTERS (2)
======================================================================
===== Function 69, subfunction 3 - detach from debugged process. =====
======================================================================
Parameters:
  * eax = 69 - function number
  * ebx = 3 - subfunction number
  * ecx = identifier
Returned value:
  * function does not return value
Remarks:
  * If the process was suspended, it resumes execution.

---------------------- Constants for registers: ----------------------
  eax - SF_DEBUG (69)
  ebx - SSF_DETACH (3)
======================================================================
======== Function 69, subfunction 4 - suspend debugged thread. =======
======================================================================
Parameters:
  * eax = 69 - function number
  * ebx = 4 - subfunction number
  * ecx = thread identifier
Returned value:
  * function does not return value
Remarks:
  * Process must be loaded for debugging (as is shown in
    general description).

---------------------- Constants for registers: ----------------------
  eax - SF_DEBUG (69)
  ebx - SSF_SUSPEND (4)
======================================================================
======== Function 69, subfunction 5 - resume debugged thread. ========
======================================================================
Parameters:
  * eax = 69 - function number
  * ebx = 5 - subfunction number
  * ecx = thread identifier
Returned value:
  * function does not return value
Remarks:
  * Process must be loaded for debugging (as is shown in
    general description).

---------------------- Constants for registers: ----------------------
  eax - SF_DEBUG (69)
  ebx - SSF_RESUME (5)
======================================================================
= Fucntion 69, subfunction 6 - read from memory of debugged process. =
======================================================================
Parameters:
  * eax = 69 - function number
  * ebx = 6 - subfunction number
  * ecx = identifier
  * edx = number of bytes to read
  * esi = address in the memory of debugged process
  * edi = pointer to buffer for data
Returned value:
  * eax = -1 at an error (invalid PID or buffer)
  * otherwise eax = number of read bytes (possibly, 0,
    if esi is too large)
Remarks:
  * Process must be loaded for debugging (as is shown in
    general description).

---------------------- Constants for registers: ----------------------
  eax - SF_DEBUG (69)
  ebx - SSF_READ_MEMORY (6)
======================================================================
== Function 69, subfunction 7 - write to memory of debugged process. =
======================================================================
Parameters:
  * eax = 69 - function number
  * ebx = 7 - subfunction number
  * ecx = identifier
  * edx = number of bytes to write
  * esi = address of memory in debugged process
  * edi = pointer to data
Returned value:
  * eax = -1 at an error (invalid PID or buffer)
  * otherwise eax = number of written bytes (possibly, 0,
    if esi is too large)
Remarks:
  * Process must be loaded for debugging (as is shown in
    general description).

---------------------- Constants for registers: ----------------------
  eax - SF_DEBUG (69)
  ebx - SSF_WRITE_MEMORY (7)
======================================================================
======= Function 69, subfunction 8 - terminate debugged thread. ======
======================================================================
Parameters:
  * eax = 69 - function number
  * ebx = 8 - subfunction number
  * ecx = identifier
Returned value:
  * function does not return value
Remarks:
  * Process must be loaded for debugging (as is shown in
    general description).
  * The function is similar to subfunction 2 of function 18
    with two differences: it requires first remark and
    accepts PID rather than slot number.

---------------------- Constants for registers: ----------------------
  eax - SF_DEBUG (69)
  ebx - SSF_TERMINATE (8)
======================================================================
===== Function 69, subfunction 9 - set/clear hardware breakpoint. ====
======================================================================
Parameters:
  * eax = 69 - function number
  * ebx = 9 - subfunction number
  * ecx = thread identifier
  * dl = index of breakpoint, from 0 to 3 inclusively
  * dh = flags:
    * if high bit is cleared - set breakpoint:
      * bits 0-1 - condition:
        * 00 = breakpoint on execution
        * 01 = breakpoint on read
        * 11 = breakpoint on read/write
      * bits 2-3 - length; for breakpoints on exception it must be
        00, otherwise one of
        * 00 = byte
        * 01 = word
        * 11 = dword
      * esi = breakpoint address; must be aligned according to
        the length (i.e. must be even for word breakpoints,
        divisible by 4 for dword)
    * if high bit is set - clear breakpoint
Returned value:
  * eax = 0 - success
  * eax = 1 - error in the input data
  * eax = 2 - (reserved, is never returned in the current
    implementation) a global breakpoint with that index is already set
Remarks:
  * Process must be loaded for debugging (as is shown in
    general description).
  * Hardware breakpoints are implemented through DRx-registers of
    the processor, all limitations results from this.
  * The function can reinstall the breakpoint, previously set
    by it (and it does not inform on this).
    Carry on the list of set breakpoints in the debugger.
  * Breakpoints generate debug exception #DB, on which the system
    notifies debugger.
  * Breakpoints on write and read/write act after
    execution of the caused it instruction.

---------------------- Constants for registers: ----------------------
  eax - SF_DEBUG (69)
  ebx - SSF_DEFINE_BREAKPOINT (9)
======================================================================
==== Function 70 - work with file system with long names support. ====
======================================================================
Parameters:
  * eax = 70
  * ebx = pointer to the information structure
Returned value:
  * eax = 0 - success; otherwise file system error code
  * some subfunctions return value in other registers too
General format of the information structure:
  * +0: dword: subfunction number
  * +4: dword: file offset
  * +8: dword: high dword of offset (must be 0) or flags field
  * +12 = +0xC: dword: size
  * +16 = +0x10: dword: pointer to data
  * +20 = +0x14: n db: ASCIIZ-string with the filename
    or
  * +20 = +0x14: db 0
  * +21 = +0x15: dd pointer to ASCIIZ-string with the filename
Specifications - in documentation on the appropriate subfunction.
Filename is case-insensitive. Russian letters must be written in
the encoding cp866 (DOS).
Format of filename:
/base/number/dir1/dir2/.../dirn/file,
where /base/number identifies device, on which file is located:
one of
  * /RD/1 = /RAMDISK/1 to access ramdisk
  * /FD/1 = /FLOPPYDISK/1 to access first floppy drive,
    /FD/2 = /FLOPPYDISK/2 to access second one
  * /HD0/x, /HD1/x, /HD2/x, /HD3/x to access accordingly to devices
    IDE0 (Primary Master), IDE1 (Primary Slave),
    IDE2 (Secondary Master), IDE3 (Secondary Slave);
    x - partition number on the selected hard drive, varies from 1
    to 255 (on each hard drive the indexing starts from 1)
  * /CD0/1, /CD1/1, /CD2/1, /CD3/1 to access accordingly to
    CD on IDE0 (Primary Master), IDE1 (Primary Slave),
    IDE2 (Secondary Master), IDE3 (Secondary Slave)
  * /SYS means system folder; with the usual boot (from floppy)
    is equivalent to /RD/1
Examples:
  * '/rd/1/kernel.asm',0
  * '/HD0/1/kernel.asm',0
  * '/hd0/2/menuet/pics/tanzania.bmp',0
  * '/hd0/1/Program files/NameOfProgram/SomeFile.SomeExtension',0
  * '/sys/MySuperApp.ini',0
Also function supports relative names.  If the path begins not
with '/', it is considered relative to a current folder. To get or
set a current folder, use the function 30.

Available subfunctions:
  * subfunction 0 - read file
  * subfunction 1 - read folder
  * subfunction 2 - create/rewrite file
  * subfunction 3 - write to existing file
  * subfunction 4 - set file size
  * subfunction 5 - get attributes of file/folder
  * subfunction 6 - set attributes of file/folder
  * subfunction 7 - start application
  * subfunction 8 - delete file/folder
  * subfunction 9 - create folder
For CD-drives due to hardware limitations only subfunctions
0,1,5 and 7 are available, other subfunctions return error
with code 2.
At the first call of subfunctions 0,1,5,7 to ATAPI devices
(CD and DVD) the manual control of tray is locked due to caching
drive data. Unlocking is made when subfunction 4 of function 24
is called for corresponding device.

---------------------- Constants for registers: ----------------------
  eax - SF_FILE (70)
 [ebx] - SSF_READ_FILE (0), SSF_READ_FOLDER (1), SSF_CREATE_FILE (2),
    SSF_WRITE_FILE (3), SSF_SET_END (4), SSF_GET_INFO (5),
    SSF_SET_INFO (6), SSF_START_APP (7), SSF_DELETE (8),
    SSF_CREATE_FOLDER (9)
======================================================================
=== Function 70, subfunction 0 - read file with long names support. ==
======================================================================
Parameters:
  * eax = 70 - function number
  * ebx = pointer to the information structure
Format of the information structure:
  * +0: dword: 0 = subfunction number
  * +4: dword: file offset (in bytes)
  * +8: dword: 0 (reserved for high dword of offset)
  * +12 = +0xC: dword: number of bytes to read
  * +16 = +0x10: dword: pointer to buffer for data
  * +20 = +0x14: ASCIIZ-name of file, the rules of names forming are
    given in the general description
    or
  * +20 = +0x14: db 0
  * +21 = +0x15: dd pointer to ASCIIZ-string with file name
Returned value:
  * eax = 0 - success, otherwise file system error code
  * ebx = number of read bytes or -1=0xffffffff if file was not found
Remarks:
  * If file was ended before last requested block was read,
    the function will read as many as it can, and after that return
    eax=6 (EOF).
  * The function does not allow to read folder (returns eax=10,
    access denied).

---------------------- Constants for registers: ----------------------
  eax - SF_FILE (70)
 [ebx] - SSF_READ_FILE (0)
======================================================================
== Function 70, subfunction 1 - read folder with long names support. =
======================================================================
Parameters:
  * eax = 70 - function number
  * ebx = pointer to the information structure
Format of the information structure:
  * +0: dword: 1 = subfunction number
  * +4: dword: index of starting block (beginning from 0)
  * +8: dword: flags field:
    * bit 0 (mask 1): in what format to return names,
      0=ANSI, 1=UNICODE
    * other bits are reserved and must be set to 0 for the future
      compatibility
  * +12 = +0xC: dword: number of blocks to read
  * +16 = +0x10: dword: pointer to buffer for data, buffer size
    must be not less than 32 + [+12]*560 bytes
  * +20 = +0x14: ASCIIZ-name of folder, the rules of names forming are
    given in the general description
    or
  * +20 = +0x14: db 0
  * +21 = +0x15: dd pointer to ASCIIZ-string with file name
Returned value:
  * eax = 0 - success, otherwise file system error code
  * ebx = number of files, information on which was written to
    the buffer, or -1=0xffffffff, if folder was not found
Structure of the buffer:
  * +0: 32*byte: header
  * +32 = +0x20: n1*byte: block with information on file 1
  * +32+n1: n2*byte: block with information on file 2
  * ...
Structure of header:
  * +0: dword: version of structure (current is 1)
  * +4: dword: number of placed blocks; is not greater than requested
    in the field +12 of information structure; can be less, if
    there are no more files in folder (the same as in ebx)
  * +8: dword: total number of files in folder
  * +12 = +0xC: 20*byte: reserved (zeroed)
Structure of block of data for folder entry (BDFE):
  * +0: dword: attributes of file:
    * bit 0 (mask 1): file is read-only
    * bit 1 (mask 2): file is hidden
    * bit 2 (mask 4): file is system
    * bit 3 (mask 8): this is not a file but volume label
      (for one partition meets no more than once and
      only in root folder)
    * bit 4 (mask 0x10): this is a folder
    * bit 5 (mask 0x20): file was not archived - many archivation
      programs have an option to archive only files with this bit set,
      and after archiving this bit is cleared - it can be useful
      for automatically creating of backup-archives as at writing
      this bit is usually set
  * +4: byte: type of name data:
    (coincides with bit 0 of flags in the information structure)
    * 0 = ASCII = 1-byte representation of each character
    * 1 = UNICODE = 2-byte representation of each character
  * +5: 3*byte: reserved (zero)
  * +8: 4*byte: time of file creation
  * +12 = +0xC: 4*byte: date of file creation
  * +16 = +0x10: 4*byte: time of last access (read or write)
  * +20 = +0x14: 4*byte: date of last access
  * +24 = +0x18: 4*byte: time of last modification
  * +28 = +0x1C: 4*byte: date of last modification
  * +32 = +0x20: qword: file size in bytes (up to 16777216 Tb)
  * +40 = +0x28: name
    * for ASCII format: maximum length is 263 characters
      (263 bytes), byte after the name has value 0
    * for UNICODE format: maximum length is 259 characters
      (518 bytes), 2 bytes after the name have value 0
Time format:
  * +0: byte: seconds
  * +1: byte: minutes
  * +2: byte: hours
  * +3: byte: reserved (0)
  * for example, 23.59.59 is written as (in hex) 3B 3B 17 00
Date format:
  * +0: byte: day
  * +1: byte: month
  * +2: word: year
  * for example, 25.11.1979 is written as (in hex) 19 0B BB 07
Remarks:
  * If BDFE contains ASCII name, the length of BDFE is 304 bytes,
    if UNICODE name - 560 bytes. Value of length is aligned
    on 16-byte bound (to accelerate processing in CPU cache).
  * First character after a name is zero (ASCIIZ-string). The further
    data contain garbage.
  * If files in folder were ended before requested number was read,
    the function will read as many as it can, and after that return
    eax=6 (EOF).
  * Any folder on the disk, except for root, contains two special
    entries "." and "..", identifying accordingly the folder itself
    and the parent folder.
  * The function allows also to read virtual folders "/", "/rd",
    "/fd", "/hd[n]", thus attributes of subfolders are set to 0x10,
    and times and dates are zeroed. An alternative way to get the
    equipment information - subfunction 11 of function 18.

---------------------- Constants for registers: ----------------------
  eax - SF_FILE (70)
 [ebx] - SSF_READ_FOLDER (1)
======================================================================
===================== Function 70, subfunction 2 =====================
============ Create/rewrite file with long names support. ============
======================================================================
Parameters:
  * eax = 70 - function number
  * ebx = pointer to the information structure
Format of the information structure:
  * +0: dword: 2 = subfunction number
  * +4: dword: 0 (reserved)
  * +8: dword: 0 (reserved)
  * +12 = +0xC: dword: number of bytes to write
  * +16 = +0x10: dword: pointer to data
  * +20 = +0x14: ASCIIZ-name of file, the rules of names forming are
    given in the general description
    or
  * +20 = +0x14: db 0
  * +21 = +0x15: dd pointer to ASCIIZ-string with file name
Returned value:
  * eax = 0 - success, otherwise file system error code
  * ebx = number of written bytes (possibly 0)
Remarks:
  * If a file with given name did not exist, it is created;
    if it existed, it is rewritten.
  * If there is not enough free space on disk, the function will
    write as many as can and then return error code 8.
  * The function is not supported for CD (returns error code 2).

---------------------- Constants for registers: ----------------------
  eax - SF_FILE (70)
 [ebx] - SSF_CREATE_FILE (2)
======================================================================
===================== Function 70, subfunction 3 =====================
=========== Write to existing file with long names support. ==========
======================================================================
Parameters:
  * eax = 70 - function number
  * ebx = pointer to the information structure
Format of the information structure:
  * +0: dword: 3 = subfunction number
  * +4: dword: file offset (in bytes)
  * +8: dword: high dword of offset (must be 0 for FAT)
  * +12 = +0xC: dword: number of bytes to write
  * +16 = +0x10: dword: pointer to data
  * +20 = +0x14: ASCIIZ-name of file, the rules of names forming are
    given in the general description
    or
  * +20 = +0x14: db 0
  * +21 = +0x15: dd pointer to ASCIIZ-string with file name
Returned value:
  * eax = 0 - success, otherwise file system error code
  * ebx = number of written bytes (possibly 0)
Remarks:
  * The file must already exist, otherwise function returns eax=5.
  * The only result of write 0 bytes is update in the file attributes
    date/time of modification and access to the current date/time.
  * If beginning and/or ending position is greater than file size
    (except for the previous case), the file is expanded to needed
    size with zero characters.
  * The function is not supported for CD (returns error code 2).

---------------------- Constants for registers: ----------------------
  eax - SF_FILE (70)
 [ebx] - SSF_WRITE_FILE (3)
======================================================================
============ Function 70, subfunction 4 - set end of file. ===========
======================================================================
Parameters:
  * eax = 70 - function number
  * ebx = pointer to the information structure
Format of the information structure:
  * +0: dword: 4 = subfunction number
  * +4: dword: low dword of new file size
  * +8: dword: high dword of new file size (must be 0 for FAT)
  * +12 = +0xC: dword: 0 (reserved)
  * +16 = +0x10: dword: 0 (reserved)
  * +20 = +0x14: ASCIIZ-name of file, the rules of names forming are
    given in the general description
    or
  * +20 = +0x14: db 0
  * +21 = +0x15: dd pointer to ASCIIZ-string with file name
Returned value:
  * eax = 0 - success, otherwise file system error code
  * ebx destroyed
Remarks:
  * If the new file size is less than old one, file is truncated.
    If the new size is greater than old one, file is expanded with
    characters with code 0. If the new size is equal to old one,
    the only result of call is set date/time of modification and
    access to the current date/time.
  * If there is not enough free space on disk for expansion, the
    function will expand to maximum possible size and then return
    error code 8.
  * The function is not supported for CD (returns error code 2).

---------------------- Constants for registers: ----------------------
  eax - SF_FILE (70)
 [ebx] - SSF_SET_END (4)
======================================================================
==== Function 70, subfunction 5 - get information on file/folder. ====
======================================================================
Parameters:
  * eax = 70 - function number
  * ebx = pointer to the information structure
Format of the information structure:
  * +0: dword: 5 = subfunction number
  * +4: dword: 0 (reserved)
  * +8: dword: 0 (reserved)
  * +12 = +0xC: dword: 0 (reserved)
  * +16 = +0x10: dword: pointer to buffer for data (40 bytes)
  * +20 = +0x14: ASCIIZ-name of file, the rules of names forming are
    given in the general description
    or
  * +20 = +0x14: db 0
  * +21 = +0x15: dd pointer to ASCIIZ-string with file name
Returned value:
  * eax = 0 - success, otherwise file system error code
  * ebx destroyed
Information on file is returned in the BDFE format (block of data
for folder entry), explained in the description of
subfunction 1, but without filename
(i.e. only first 40 = 0x28 bytes).
Remarks:
  * The function does not support virtual folders such as /, /rd and
    root folders like /rd/1.

---------------------- Constants for registers: ----------------------
  eax - SF_FILE (70)
 [ebx] - SSF_GET_INFO (5)
======================================================================
===== Function 70, subfunction 6 - set attributes of file/folder. ====
======================================================================
Parameters:
  * eax = 70 - function number
  * ebx = pointer to the information structure
Format of the information structure:
  * +0: dword: 6 = subfunction number
  * +4: dword: 0 (reserved)
  * +8: dword: 0 (reserved)
  * +12 = +0xC: dword: 0 (reserved)
  * +16 = +0x10: dword: pointer to buffer with attributes (32 bytes)
  * +20 = +0x14: ASCIIZ-name of file, the rules of names forming are
    given in the general description
    or
  * +20 = +0x14: db 0
  * +21 = +0x15: dd pointer to ASCIIZ-string with file name
Returned value:
  * eax = 0 - success, otherwise file system error code
  * ebx destroyed
File attributes are first 32 bytes in BDFE (block of data
for folder entry), explained in the description of subfunction 1
(that is, without name and size of file). Attribute
file/folder/volume label (bits 3,4 in dword +0) is not changed.
Byte +4 (name format) is ignored.
Remarks:
  * The function does not support virtual folders such as /, /rd and
    root folders like /rd/1.
  * The function is not supported for CD (returns error code 2).

---------------------- Constants for registers: ----------------------
  eax - SF_FILE (70)
 [ebx] - SSF_SET_INFO (6)
======================================================================
=========== Function 70, subfunction 7 - start application. ==========
======================================================================
Parameters:
  * eax = 70 - function number
  * ebx = pointer to the information structure
Format of the information structure:
  * +0: dword: 7 = subfunction number
  * +4: dword: flags field:
    * bit 0: start process as debugged
    * other bits are reserved and must be set to 0
  * +8: dword: 0 or pointer to ASCIIZ-string with parameters
  * +12 = +0xC: dword: 0 (reserved)
  * +16 = +0x10: dword: 0 (reserved)
  * +20 = +0x14: ASCIIZ-name of file, the rules of names forming are
    given in the general description
    or
  * +20 = +0x14: db 0
  * +21 = +0x15: dd pointer to ASCIIZ-string with file name
Returned value:
  * eax > 0 - program is loaded, eax contains PID
  * eax < 0 - an error has occured, -eax contains
    file system error code
  * ebx destroyed
Remarks:
  * Command line must be terminated by the character with the code 0
    (ASCIIZ-string); function takes into account either all characters
    up to terminating zero inclusively or first 256 character
    regarding what is less.
  * If the process is started as debugged, it is created in
    the suspended state; to run use subfunction 5 of function 69.

---------------------- Constants for registers: ----------------------
  eax - SF_FILE (70)
 [ebx] - SSF_START_APP (7)
======================================================================
========== Function 70, subfunction 8 - delete file/folder. ==========
======================================================================
Parameters:
  * eax = 70 - function number
  * ebx = pointer to the information structure
Format of the information structure:
  * +0: dword: 8 = subfunction number
  * +4: dword: 0 (reserved)
  * +8: dword: 0 (reserved)
  * +12 = +0xC: dword: 0 (reserved)
  * +16 = +0x10: dword: 0 (reserved)
  * +20 = +0x14: ASCIIZ-name of file, the rules of names forming are
    given in the general description
    or
  * +20 = +0x14: db 0
  * +21 = +0x15: dd pointer to ASCIIZ-string with file name
Returned value:
  * eax = 0 - success, otherwise file system error code
  * ebx destroyed
Remarks:
  * The function is not supported for CD (returns error code 2).
  * The function can delete only empty folders (attempt to delete
    nonempty folder results in error with code 10, "access denied").

---------------------- Constants for registers: ----------------------
  eax - SF_FILE (70)
 [ebx] - SSF_DELETE (8)
======================================================================
============= Function 70, subfunction 9 - create folder. ============
======================================================================
Parameters:
  * eax = 70 - function number
  * ebx = pointer to the information structure
Format of the information structure:
  * +0: dword: 9 = subfunction number
  * +4: dword: 0 (reserved)
  * +8: dword: 0 (reserved)
  * +12 = +0xC: dword: 0 (reserved)
  * +16 = +0x10: dword: 0 (reserved)
  * +20 = +0x14: ASCIIZ-name of folder, the rules of names forming are
    given in the general description
    or
  * +20 = +0x14: db 0
  * +21 = +0x15: dd pointer to ASCIIZ-string with folder name
Returned value:
  * eax = 0 - success, otherwise file system error code
  * ebx destroyed
Remarks:
  * The function is not supported for CD (returns error code 2).
  * The parent folder must already exist.
  * If target folder already exists, function returns success (eax=0).

---------------------- Constants for registers: ----------------------
  eax - SF_FILE (70)
 [ebx] - SSF_CREATE_FOLDER (9)
======================================================================
========== Function 71, subfunction 1 - set window caption. ==========
======================================================================
Parameters:
  * eax = 71 - function number
  * ebx = 1 - subfunction number
  * ecx = pointer to zero terminated string
Returned value:
  * function does not return value
Remarks:
  * You may set the caption string encoding by putting
    at the start of the string a byte with next values:
    1 = cp866
    2 = UTF-16LE
    3 = UTF-8
    otherwise will be used cp866.
  * Pass NULL in ecx to remove caption.

---------------------- Constants for registers: ----------------------
  eax - SF_SET_CAPTION (71)
======================================================================
=============== Function 72 - send message to a window. ==============
======================================================================

- Subfunction 1 - send message with parameter to the active window. --
Parameters:
  * eax = 72 - function number
  * ebx = 1 - subfunction number
  * ecx = event code: 2 or 3
  * edx = parameter: key code for ecx=2, button identifier for ecx=3
Returned value:
  * eax = 0 - success
  * eax = 1 - buffer is full

---------------------- Constants for registers: ----------------------
  eax - SF_SEND_MESSAGE (72)
======================================================================
===================== Function 73 - blit bitmap  =====================
======================================================================

Parameters:
  * eax = 73 - function number

  * ebx = ROP and optional flags
     31           6 5  4 3   0
     [  reserved  ][T][B][ROP]
     ROP - raster operation code
        0: Copy
     1-15: reserved
     B   - blit into the background surface
     T   - transparent blit

  * ecx = pointer to the function parameters
        destination offset and clipping
     +0 signed dword: destination rectangle X offset from the window
                      top-left corner
     +4 signed dword: destination rectangle Y offset from the window
                      top-left corner
     +8 dword:        destination rectangle width
    +12 dword:        destination rectangle height

        source offset and clipping
    +16 signed dword: source rectangle X offset from the bitmap
                      top-left corner
    +20 signed dword: source rectangle Y offset from the bitmap
                      top-left corner
    +24 dword:        source rectangle width
    +28 dword:        source rectangle height

    +32: dword: bitmap data - must be 32bpp
    +36: dword: size of the bitmap row in bytes

Returned value:
  * function does not return value

---------------------- Constants for registers: ----------------------
  eax - SF_BLITTER (73)
======================================================================
= Function 74, Subfunction 255, Get number of active network devices. =
======================================================================
Parameters:
  * eax = 74 - function number
  * bl = 255 - subfunction number
Returned value:
  * eax = number of active network devices

---------------------- Constants for registers: ----------------------
  eax - SF_NETWORK_GET (74)
   bl - SSF_DEVICE_COUNT (255)
======================================================================
======== Function 74, Subfunction 0, Get network device type. ========
======================================================================
Parameters:
  * eax = 74 - function number
  * bl = 0 - subfunction number
  * bh = device number
Returned value:
  * eax = device type number

---------------------- Constants for registers: ----------------------
  eax - SF_NETWORK_GET (74)
   bl - SSF_DEVICE_TYPE (0)
======================================================================
======== Function 74, Subfunction 1, Get network device name. ========
======================================================================
Parameters:
  * eax = 74 - function number
  * bl = 1 - subfunction number
  * bh = device number
  * ecx = pointer to 64 byte buffer
Returned value:
  * eax = -1 on error
  * The network device name is written into the buffer, on success

---------------------- Constants for registers: ----------------------
  eax - SF_NETWORK_GET (74)
   bl - SSF_DEVICE_NAME (1)
======================================================================
========= Function 74, Subfunction 2, Reset network device. ==========
======================================================================
Parameters:
  * eax = 74 - function number
  * bl = 2 - subfunction number
  * bh = device number
Returned value:
  * eax = -1 on error

---------------------- Constants for registers: ----------------------
  eax - SF_NETWORK_GET (74)
   bl - SSF_RESET_DEVICE (2)
======================================================================
========== Function 74, Subfunction 3, Stop network device. ==========
======================================================================
Parameters:
  * eax = 74 - function number
  * bl = 3 - subfunction number
  * bh = device number
Returned value:
  * eax = -1 on error

---------------------- Constants for registers: ----------------------
  eax - SF_NETWORK_GET (74)
   bl - SSF_STOP_DEVICE (3)
======================================================================
=========== Function 74, Subfunction 4, Get device pointer. ==========
======================================================================
Parameters:
  * eax = 74 - function number
  * bl = 4 - subfunction number
  * bh = device number
Returned value:
  * eax = device pointer, -1 on error

---------------------- Constants for registers: ----------------------
  eax - SF_NETWORK_GET (74)
   bl - SSF_DEVICE_POINER (4)
======================================================================
========= Function 74, Subfunction 6, Get packet TX counter. =========
======================================================================
Parameters:
  * eax = 74 - function number
  * bl = 6 - subfunction number
  * bh = device number
Returned value:
  * eax = Number of packets sent since device start, -1 on error

---------------------- Constants for registers: ----------------------
  eax - SF_NETWORK_GET (74)
   bl - SSF_TX_PACKET_COUNT (6)
======================================================================
========= Function 74, Subfunction 7, Get packet RX counter. =========
======================================================================
Parameters:
  * eax = 74 - function number
  * bl = 7 - subfunction number
  * bh = device number
Returned value:
  * eax = Number of packets received since device start, -1 on error

---------------------- Constants for registers: ----------------------
  eax - SF_NETWORK_GET (74)
   bl - SSF_RX_PACKET_COUNT (7)
======================================================================
========== Function 74, Subfunction 8, Get TX byte counter. ==========
======================================================================
Parameters:
  * eax = 74 - function number
  * bl = 8 - subfunction number
  * bh = device number
Returned value:
  * eax = Number of bytes sent since device start (lower dword)
                  -1 on error
  * ebx = Number of bytes sent since device start (higher dword)

---------------------- Constants for registers: ----------------------
  eax - SF_NETWORK_GET (74)
   bl - SSF_TX_BYTE_COUNT (8)
======================================================================
========== Function 74, Subfunction 9, Get RX byte counter. ==========
======================================================================
Parameters:
  * eax = 74 - function number
  * bl = 9 - subfunction number
  * bh = device number
Returned value:
  * eax = Number of bytes received since device start (lower dword)
                  -1 on error
  * ebx = Number of bytes received since device start (higher dword)

---------------------- Constants for registers: ----------------------
  eax - SF_NETWORK_GET (74)
   bl - SSF_RX_BYTE_COUNT (9)
======================================================================
========== Function 74, Subfunction 10, Get link status. =============
======================================================================
Parameters:
  * eax = 74 - function number
  * bl = 10 - subfunction number
  * bh = device number
Returned value:
  * eax = link status, -1 on error

  Link status:
    ETH_LINK_DOWN   =    0b         ; Link is down
    ETH_LINK_UNKNOWN=    1b         ; There could be an active link
    ETH_LINK_FD     =   10b         ; full duplex flag
    ETH_LINK_10M    =  100b         ; 10 mbit
    ETH_LINK_100M   = 1000b         ; 100 mbit
    ETH_LINK_1G     = 1100b         ; gigabit

---------------------- Constants for registers: ----------------------
  eax - SF_NETWORK_GET (74)
   bl - SSF_LINK_STATUS (10)
======================================================================
============== Function 75, Subfunction 0, Open socket. ==============
======================================================================
Parameters:
  * eax = 75 - function number
  * bl = 0 - subfunction number
  * ecx = domain
  * edx = type
  * esi = protocol
Returned value:
  * eax = socket number, -1 on error
  * ebx = errorcode

---------------------- Constants for registers: ----------------------
  eax - SF_NETWORK_SOCKET (75)
   bl - SSF_OPEN (0)
======================================================================
============= Function 75, Subfunction 1, Close socket. ==============
======================================================================
Parameters:
  * eax = 75 - function number
  * bl = 1 - subfunction number
  * ecx = socket number
Returned value:
  * eax = -1 on error
  * ebx = errorcode

---------------------- Constants for registers: ----------------------
  eax - SF_NETWORK_SOCKET (75)
   bl - SSF_CLOSE (1)
======================================================================
================== Function 75, Subfunction 2, Bind. =================
======================================================================
Parameters:
  * eax = 75 - function number
  * bl = 2 - subfunction number
  * ecx = socket number
  * edx = pointer to sockaddr structure
  * esi = length of sockaddr structure
Returned value:
  * eax = -1 on error
  * ebx = errorcode

---------------------- Constants for registers: ----------------------
  eax - SF_NETWORK_SOCKET (75)
   bl - SSF_BIND (2)
======================================================================
================= Function 75, Subfunction 3, Listen. ================
======================================================================
Parameters:
  * eax = 75 - function number
  * bl = 3 - subfunction number
  * ecx = socket number
  * edx = backlog
Returned value:
  * eax = -1 on error
  * ebx = errorcode

---------------------- Constants for registers: ----------------------
  eax - SF_NETWORK_SOCKET (75)
   bl - SSF_LISTEN (3)
======================================================================
================ Function 75, Subfunction 4, Connect. ================
======================================================================
Parameters:
  * eax = 75 - function number
  * bl = 4 - subfunction number
  * ecx = socket number
  * edx = pointer to sockaddr structure
  * esi = length of sockaddr structure
Returned value:
  * eax = -1 on error
  * ebx = errorcode

---------------------- Constants for registers: ----------------------
  eax - SF_NETWORK_SOCKET (75)
   bl - SSF_CONNECT (4)
======================================================================
================= Function 75, Subfunction 5, Accept. ================
======================================================================
Parameters:
  * eax = 75 - function number
  * bl = 5 - subfunction number
  * ecx = socket number
  * edx = pointer to sockaddr structure
  * esi = length of sockaddr structure
Returned value:
  * eax = socket number of accepted socket, -1 on error
  * ebx = errorcode

---------------------- Constants for registers: ----------------------
  eax - SF_NETWORK_SOCKET (75)
   bl - SSF_ACCEPT (5)
======================================================================
================== Function 75, Subfunction 6, Send. =================
======================================================================
Parameters:
  * eax = 75 - function number
  * bl = 6 - subfunction number
  * ecx = socket number
  * edx = pointer to buffer
  * esi = length of buffer
  * edi = flags
Returned value:
  * eax = number of bytes copied, -1 on error
  * ebx = errorcode

---------------------- Constants for registers: ----------------------
  eax - SF_NETWORK_SOCKET (75)
   bl - SSF_SEND (6)
======================================================================
================ Function 75, Subfunction 7, Receive. ================
======================================================================
Parameters:
  * eax = 75 - function number
  * bl = 7 - subfunction number
  * ecx = socket number
  * edx = pointer to buffer
  * esi = length of buffer
  * edi = flags
Returned value:
  * eax = number of bytes copied, -1 on error
  * ebx = errorcode

---------------------- Constants for registers: ----------------------
  eax - SF_NETWORK_SOCKET (75)
   bl - SSF_RECEIVE (7)
======================================================================
=========== Function 75, Subfunction 8, Set socket options. ==========
======================================================================
Parameters:
  * eax = 75 - function number
  * bl = 8 - subfunction number
  * ecx = socket number
  * edx = pointer to optstruct
Returned value:
  * eax = -1 on error
  * ebx = errorcode
Remarks:

  Optstruct: 
    dd level
    dd optionname
    dd optlength
    db options...

---------------------- Constants for registers: ----------------------
  eax - SF_NETWORK_SOCKET (75)
   bl - SSF_SET_OPTIONS (8)
======================================================================
=========== Function 75, Subfunction 9, Get socket options. ==========
======================================================================
Parameters:
  * eax = 75 - function number
  * bl = 9 - subfunction number
  * ecx = socket number
  * edx = pointer to optstruct
Returned value:
  * eax = -1 on error
  * ebx = errorcode
Remarks:

  Optstruct: 
    dd level
    dd optionname
    dd optlength
    db options...

---------------------- Constants for registers: ----------------------
  eax - SF_NETWORK_SOCKET (75)
   bl - SSF_GET_OPTIONS (9)
======================================================================
============ Function 75, Subfunction 10, Get socketpair. ===========
======================================================================
Parameters:
  * eax = 75 - function number
  * bl = 10 - subfunction number
Returned value:
  * eax = socketnum1, -1 on error
  * ebx = socketnum2, errorcode on error

---------------------- Constants for registers: ----------------------
  eax - SF_NETWORK_SOCKET (75)
   bl - SSF_GET_PAIR (10)
======================================================================
============ Function 76, Network options and statistics. ============
======================================================================
Parameters:
  * eax = 76 - function number
  * high half of ebx = protocol number
  * bh = device number
  * bl = subfunction number

Ethernet (0)
        0 - Read MAC
        
IPv4 (1)
        0 - Read # IP packets sent
        1 - Read # IP packets received
        2 - Read IP
        3 - Write IP
        4 - Read DNS
        5 - Write DNS
        6 - Read subnet
        7 - Write subnet
        8 - Read gateway
        9 - Write gateway
        
ICMP (2)
        0 - Read # ICMP packets sent
        1 - Read # ICMP packets received
        3 - enable/disable ICMP echo reply

UDP (3)
        0 - Read # UDP packets sent
        1 - Read # UDP packets received

TCP (4)
        0 - Read # TCP packets sent
        1 - Read # TCP packets received 
        
ARP (5)
        0 - Read # ARP packets sent
        1 - Read # ARP packets received
        2 - Read # ARP entry's
        3 - Read ARP entry
        4 - Add static ARP entry
        5 - Remove ARP entry (-1 = remove all)
        6 - Send ARP announce on specified interface
        7 - Read # ARP conflicts (IP address conflicts) 

---------------------- Constants for registers: ----------------------
  eax - SF_NETWORK_PROTOCOL (76)
======================================================================
=============== Function -1 - terminate thread/process ===============
======================================================================
Parameters:
  * eax = -1 - function number
Returned value:
  * function does not return neither value nor control
Remarks:
  * If the process did not create threads obviously, it has only
    one thread, which termination results in process termination.
  * If the current thread is last in the process, its termination
    also results in process terminates.
  * This function terminates the current thread. Other thread can be
    killed by call to subfunction 2 of function 18.

======================================================================
=========================== List of events ===========================
======================================================================
Next event can be retrieved by the call of one from functions 10
(to wait for event), 11 (to check without waiting), 23
(to wait during the given time).
These functions return only those events, which enter into a mask set
by function 40. By default it is first three,
there is enough for most applications.
Codes of events:
  * 1 = redraw event (is reset by call to function 0)
  * 2 = key on keyboard is pressed (acts, only when the window is
    active) or hotkey is pressed; is reset, when all keys from
    the buffer are read out by function 2
  * 3 = button is pressed, defined earlier by function 8
    (or close button, created implicitly by function 0;
    minimize button is handled by the system and sends no message;
    acts, only when the window is active;
    is reset when all buttons from the buffer
    are read out by function 17)
  * 4 = reserved (in current implementation never comes even after
    unmasking by function 40)
  * 5 = kernel finished redrawing of the desktop background
  * 6 = mouse event (something happened - button pressing or moving;
    is reset at reading)
  * 7 = IPC event (see function 60 -
    Inter Process Communication; is reset at reading)
  * 8 = network event (is reset at reading)
  * 9 = debug event (is reset at reading; see
    debug subsystem)
  * 16..31 = event with appropriate IRQ
    (16=IRQ0, 31=IRQ15) (is reset after reading all IRQ data)

======================================================================
=================== Error codes of the file system ===================
======================================================================
  * 0 = success
  * 1 = base and/or partition of a hard disk is not defined
    (by subfunctions 7, 8 of function 21)
  * 2 = function is not supported for the given file system
  * 3 = unknown file system
  * 4 = reserved, is never returned in the current implementation
  * 5 = file not found
  * 6 = end of file, EOF
  * 7 = pointer lies outside of application memory
  * 8 = disk is full
  * 9 = FAT table is destroyed
  * 10 = access denied
  * 11 = device error
Application start functions can return also following errors:
  * 30 = 0x1E = not enough memory
  * 31 = 0x1F = file is not executable
  * 32 = 0x20 = too many processes