kolibrios-gitea/kernel/trunk/core/sys32.inc

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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; ;;
;; Copyright (C) KolibriOS team 2004-2011. All rights reserved. ;;
;; Distributed under terms of the GNU General Public License ;;
;; ;;
;; ;;
;; MenuetOS process management, protected ring3 ;;
;; ;;
;; Distributed under GPL. See file COPYING for details. ;;
;; Copyright 2003 Ville Turjanmaa ;;
;; ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
$Revision$
align 4 ;3A08
build_interrupt_table:
mov edi, idts
mov esi, sys_int
mov ecx, 0x40
mov eax, (10001110b shl 24) + os_code
@@:
movsw ;low word of code-entry
stosd ;interrupt gate type : os_code selector
movsw ;high word of code-entry
loop @b
movsd ;copy low dword of trap gate for int 0x40
movsd ;copy high dword of trap gate for int 0x40
lidt [esi]
ret
iglobal
align 4
sys_int:
;exception handlers addresses (for interrupt gate construction)
dd e0,e1,e2,e3,e4,e5,e6,except_7 ; SEE: core/fpu.inc
dd e8,e9,e10,e11,e12,e13,page_fault_exc,e15
dd e16, e17,e18, e19
times 12 dd unknown_interrupt ;int_20..int_31
;interrupt handlers addresses (for interrupt gate construction)
; 0x20 .. 0x2F - IRQ handlers
dd irq0, irq_serv.irq_1, irq_serv.irq_2
dd irq_serv.irq_3, irq_serv.irq_4
dd irq_serv.irq_5, irq_serv.irq_6, irq_serv.irq_7
dd irq_serv.irq_8, irq_serv.irq_9, irq_serv.irq_10
dd irq_serv.irq_11, irq_serv.irq_12, irqD, irq_serv.irq_14, irq_serv.irq_15
dd irq_serv.irq_16
dd irq_serv.irq_17
dd irq_serv.irq_18
dd irq_serv.irq_19
dd irq_serv.irq_20
dd irq_serv.irq_21
dd irq_serv.irq_22
dd irq_serv.irq_23
times 32 - IRQ_RESERVED dd unknown_interrupt
;int_0x40 gate trap (for directly copied)
dw i40 and 0xFFFF, os_code, 11101111b shl 8, i40 shr 16
idtreg: ; data for LIDT instruction (!!! must be immediately below sys_int data)
dw 2*($-sys_int-4)-1
dd idts ;0x8000B100
dw 0 ;<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
msg_fault_sel dd msg_exc_8,msg_exc_u,msg_exc_a,msg_exc_b
dd msg_exc_c,msg_exc_d,msg_exc_e
msg_exc_8 db "Double fault", 0
msg_exc_u db "Undefined Exception", 0
msg_exc_a db "Invalid TSS", 0
msg_exc_b db "Segment not present", 0
msg_exc_c db "Stack fault", 0
msg_exc_d db "General protection fault", 0
msg_exc_e db "Page fault", 0
msg_sel_ker db "kernel", 0
msg_sel_app db "application", 0
endg
macro save_ring3_context {
pushad
}
macro restore_ring3_context {
popad
}
macro exc_wo_code [num] {
e#num :
save_ring3_context
mov bl, num
jmp exc_c
} exc_wo_code 0,1,2,3,4,5,6,15,16,19
macro exc_w_code [num] {
e#num :
add esp, 4
save_ring3_context
mov bl, num
jmp exc_c
} exc_w_code 8,9,10,11,12,13,17,18
uglobal
pf_err_code dd ?
endg
page_fault_exc: ; <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>: <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>...
pop [ss:pf_err_code]; <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <EFBFBD><EFBFBD> <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> #PF
save_ring3_context
mov bl, 14
exc_c: ; <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> (<EFBFBD><EFBFBD><EFBFBD>, <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 7-<EFBFBD><EFBFBD> - #NM)
; <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <EFBFBD><EFBFBD><EFBFBD> <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>/<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <EFBFBD><EFBFBD> 3-<EFBFBD><EFBFBD> <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> + pushad (<EFBFBD>.<EFBFBD>., <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
reg_ss equ esp+0x30
reg_esp3 equ esp+0x2C
reg_eflags equ esp+0x28
reg_cs3 equ esp+0x24
reg_eip equ esp+0x20
; <EFBFBD><EFBFBD><EFBFBD> <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <EFBFBD><EFBFBD> pushad
reg_eax equ esp+0x1C
reg_ecx equ esp+0x18
reg_edx equ esp+0x14
reg_ebx equ esp+0x10
reg_esp0 equ esp+0x0C
reg_ebp equ esp+0x08
reg_esi equ esp+0x04
reg_edi equ esp+0x00
mov ax, app_data ;<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
mov ds, ax ;<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
mov es, ax ;<EFBFBD> <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
cld ; <EFBFBD> <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> DF <EFBFBD> <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
movzx ebx, bl
; redirect to V86 manager? (EFLAGS & 0x20000) != 0?
test byte[reg_eflags+2], 2
jnz v86_exc_c
cmp bl, 14 ; #PF
jne @f
call page_fault_handler ; SEE: core/memory.inc
@@:
mov esi, [current_slot]
btr [esi+APPDATA.except_mask], ebx
jnc @f
mov eax, [esi+APPDATA.exc_handler]
test eax, eax
jnz IRetToUserHook
@@:
cli
mov eax, [esi+APPDATA.debugger_slot]
test eax, eax
jnz .debug
sti
; not debuggee => say error and terminate
call show_error_parameters ;; only ONE using, inline ???
;mov edx, [TASK_BASE]
mov [edx + TASKDATA.state], byte 4 ; terminate
jmp change_task ; stack - here it does not matter at all, SEE: core/shed.inc
.debug:
; we are debugged process, notify debugger and suspend ourself
; eax=debugger PID
mov ecx, 1 ; debug_message code=other_exception
cmp bl, 1 ; #DB
jne .notify ; notify debugger and suspend ourself
mov ebx, dr6 ; debug_message data=DR6_image
xor edx, edx
mov dr6, edx
mov edx, dr7
mov cl, not 8
.l1:
shl dl, 2
jc @f
and bl, cl
@@:
sar cl, 1
jc .l1
mov cl, 3 ; debug_message code=debug_exception
.notify:
push ebx ; debug_message data
mov ebx, [TASK_BASE]
push [ebx+TASKDATA.pid] ; PID
push ecx ; debug_message code ((here: ecx==1/3))
mov cl, 12 ; debug_message size
call debugger_notify ;; only ONE using, inline ??? SEE: core/debug.inc
add esp, 12
mov edx, [TASK_BASE]
mov byte [edx+TASKDATA.state], 1 ; suspended
call change_task ; SEE: core/shed.inc
restore_ring3_context
iretd
IRetToUserHook:
xchg eax, [reg_eip]
sub dword[reg_esp3], 8
mov edi, [reg_esp3]
stosd
mov [edi], ebx
restore_ring3_context
; simply return control to interrupted process
unknown_interrupt:
iretd
;-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
; bl - error vector
show_error_parameters:
cmp bl, 0x06
jnz .no_ud
push ebx
mov ebx, ud_user_message
mov ebp, notifyapp
call fs_execute_from_sysdir_param
pop ebx
.no_ud:
mov edx, [TASK_BASE];not scratched below
DEBUGF 1, "K : Process - forced terminate PID: %x [%s]\n", [edx+TASKDATA.pid], [current_slot]
cmp bl, 0x08
jb .l0
cmp bl, 0x0e
jbe .l1
.l0:
mov bl, 0x09
.l1:
mov eax, [msg_fault_sel+ebx*4 - 0x08*4]
DEBUGF 1, "K : %s\n", eax
mov eax, [reg_cs3+4]
mov edi, msg_sel_app
mov ebx, [reg_esp3+4]
cmp eax, app_code
je @f
mov edi, msg_sel_ker
mov ebx, [reg_esp0+4]
@@:
DEBUGF 1, "K : EAX : %x EBX : %x ECX : %x\n", [reg_eax+4], [reg_ebx+4], [reg_ecx+4]
DEBUGF 1, "K : EDX : %x ESI : %x EDI : %x\n", [reg_edx+4], [reg_esi+4], [reg_edi+4]
DEBUGF 1, "K : EBP : %x EIP : %x ESP : %x\n", [reg_ebp+4], [reg_eip+4], ebx
DEBUGF 1, "K : Flags : %x CS : %x (%s)\n", [reg_eflags+4], eax, edi
ret
;-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
restore reg_ss
restore reg_esp3
restore reg_eflags
restore reg_cs
restore reg_eip
restore reg_eax
restore reg_ecx
restore reg_edx
restore reg_ebx
restore reg_esp0
restore reg_ebp
restore reg_esi
restore reg_edi
align 4
set_application_table_status:
push eax
mov eax, [CURRENT_TASK]
shl eax, 5
add eax, CURRENT_TASK+TASKDATA.pid
mov eax, [eax]
mov [application_table_status], eax
pop eax
ret
align 4
clear_application_table_status:
push eax
mov eax, [CURRENT_TASK]
shl eax, 5
add eax, CURRENT_TASK+TASKDATA.pid
mov eax, [eax]
cmp eax, [application_table_status]
jne apptsl1
xor eax, eax
mov [application_table_status], eax
apptsl1:
pop eax
ret
; * eax = 64 - <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; * ebx = 1 - <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; * ecx = <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
;<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>:
; * eax = 0 - <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
; * eax = 1 - <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
align 4
sys_resize_app_memory:
; ebx = 1 - resize
; ecx = new amount of memory
; cmp eax,1
dec ebx
jnz .no_application_mem_resize
stdcall new_mem_resize, ecx
mov [esp+32], eax
.no_application_mem_resize:
ret
iglobal
; process_terminating db 'K : Process - terminating',13,10,0
; process_terminated db 'K : Process - done',13,10,0
msg_obj_destroy db 'K : destroy app object',13,10,0
endg
; param
; esi= slot
align 4
terminate: ; terminate application
.slot equ esp ;locals
push esi ;save .slot
shl esi, 8
cmp [SLOT_BASE+esi+APPDATA.dir_table], 0
jne @F
pop esi
shl esi, 5
mov [CURRENT_TASK+esi+TASKDATA.state], 9
ret
@@:
;mov esi,process_terminating
;call sys_msg_board_str
@@:
cli
cmp [application_table_status], 0
je term9
sti
call change_task
jmp @b
term9:
call set_application_table_status
; if the process is in V86 mode...
mov eax, [.slot]
shl eax, 8
mov esi, [eax+SLOT_BASE+APPDATA.pl0_stack]
add esi, RING0_STACK_SIZE
cmp [eax+SLOT_BASE+APPDATA.saved_esp0], esi
jz .nov86
; ...it has page directory for V86 mode
mov esi, [eax+SLOT_BASE+APPDATA.saved_esp0]
mov ecx, [esi+4]
mov [eax+SLOT_BASE+APPDATA.dir_table], ecx
; ...and I/O permission map for V86 mode
mov ecx, [esi+12]
mov [eax+SLOT_BASE+APPDATA.io_map], ecx
mov ecx, [esi+8]
mov [eax+SLOT_BASE+APPDATA.io_map+4], ecx
.nov86:
mov esi, [.slot]
shl esi, 8
add esi, SLOT_BASE+APP_OBJ_OFFSET
@@:
mov eax, [esi+APPOBJ.fd]
test eax, eax
jz @F
cmp eax, esi
je @F
push esi
call [eax+APPOBJ.destroy]
DEBUGF 1,"%s",msg_obj_destroy
pop esi
jmp @B
@@:
mov eax, [.slot]
shl eax, 8
stdcall destroy_app_space, [SLOT_BASE+eax+APPDATA.dir_table], [SLOT_BASE+eax+APPDATA.dlls_list_ptr]
mov esi, [.slot]
cmp [fpu_owner], esi ; if user fpu last -> fpu user = 1
jne @F
mov [fpu_owner], 1
mov eax, [256+SLOT_BASE+APPDATA.fpu_state]
clts
bt [cpu_caps], CAPS_SSE
jnc .no_SSE
fxrstor [eax]
jmp @F
.no_SSE:
fnclex
frstor [eax]
@@:
mov [KEY_COUNT], byte 0 ; empty keyboard buffer
mov [BTN_COUNT], byte 0 ; empty button buffer
; remove defined hotkeys
mov eax, hotkey_list
.loop:
cmp [eax+8], esi
jnz .cont
mov ecx, [eax]
jecxz @f
push dword [eax+12]
pop dword [ecx+12]
@@:
mov ecx, [eax+12]
push dword [eax]
pop dword [ecx]
xor ecx, ecx
mov [eax], ecx
mov [eax+4], ecx
mov [eax+8], ecx
mov [eax+12], ecx
.cont:
add eax, 16
cmp eax, hotkey_list+256*16
jb .loop
; get process PID
mov eax, esi
shl eax, 5
mov eax, [eax+CURRENT_TASK+TASKDATA.pid]
; compare current lock input with process PID
cmp eax, [PID_lock_input]
jne @f
xor eax, eax
mov [PID_lock_input], eax
@@:
; remove hotkeys in buffer
mov eax, hotkey_buffer
.loop2:
cmp [eax], esi
jnz .cont2
and dword [eax+4], 0
and dword [eax], 0
.cont2:
add eax, 8
cmp eax, hotkey_buffer+120*8
jb .loop2
mov ecx, esi ; remove buttons
bnewba2:
mov edi, [BTN_ADDR]
mov eax, edi
cld
movzx ebx, word [edi]
inc bx
bnewba:
dec bx
jz bnmba
add eax, 0x10
cmp cx, [eax]
jnz bnewba
pusha
mov ecx, ebx
inc ecx
shl ecx, 4
mov ebx, eax
add eax, 0x10
call memmove
dec dword [edi]
popa
jmp bnewba2
bnmba:
pusha ; save window coordinates for window restoring
cld
shl esi, 5
add esi, window_data
mov eax, [esi+WDATA.box.left]
mov [draw_limits.left], eax
add eax, [esi+WDATA.box.width]
mov [draw_limits.right], eax
mov eax, [esi+WDATA.box.top]
mov [draw_limits.top], eax
add eax, [esi+WDATA.box.height]
mov [draw_limits.bottom], eax
xor eax, eax
mov [esi+WDATA.box.left], eax
mov [esi+WDATA.box.width], eax
mov [esi+WDATA.box.top], eax
mov [esi+WDATA.box.height], eax
mov [esi+WDATA.cl_workarea], eax
mov [esi+WDATA.cl_titlebar], eax
mov [esi+WDATA.cl_frames], eax
mov dword [esi+WDATA.reserved], eax; clear all flags: wstate, redraw, wdrawn
lea edi, [esi-window_data+draw_data]
mov ecx, 32/4
rep stosd
popa
; debuggee test
pushad
mov edi, esi
shl edi, 5
mov eax, [SLOT_BASE+edi*8+APPDATA.debugger_slot]
test eax, eax
jz .nodebug
push 8
pop ecx
push dword [CURRENT_TASK+edi+TASKDATA.pid]; PID
push 2
call debugger_notify
pop ecx
pop ecx
.nodebug:
popad
mov ebx, [.slot]
shl ebx, 8
push ebx
mov ebx, [SLOT_BASE+ebx+APPDATA.pl0_stack]
stdcall kernel_free, ebx
pop ebx
mov ebx, [SLOT_BASE+ebx+APPDATA.cur_dir]
stdcall kernel_free, ebx
mov edi, [.slot]
shl edi, 8
add edi, SLOT_BASE
mov eax, [edi+APPDATA.io_map]
cmp eax, [SLOT_BASE+256+APPDATA.io_map]
je @F
call free_page
@@:
mov eax, [edi+APPDATA.io_map+4]
cmp eax, [SLOT_BASE+256+APPDATA.io_map+4]
je @F
call free_page
@@:
mov eax, 0x20202020
stosd
stosd
stosd
mov ecx, 244/4
xor eax, eax
rep stosd
; activate window
movzx eax, word [WIN_STACK + esi*2]
cmp eax, [TASK_COUNT]
jne .dont_activate
pushad
.check_next_window:
dec eax
cmp eax, 1
jbe .nothing_to_activate
lea esi, [WIN_POS+eax*2]
movzx edi, word [esi] ; edi = process
shl edi, 5
cmp [CURRENT_TASK + edi + TASKDATA.state], byte 9 ; skip dead slots
je .check_next_window
add edi, window_data
; \begin{diamond}[19.09.2006]
; skip minimized windows
test [edi + WDATA.fl_wstate], WSTATE_MINIMIZED
jnz .check_next_window
; \end{diamond}
call waredraw
.nothing_to_activate:
popad
.dont_activate:
push esi ; remove hd1 & cd & flp reservation
shl esi, 5
mov esi, [esi+CURRENT_TASK+TASKDATA.pid]
cmp [hd1_status], esi
jnz @f
call free_hd_channel
and [hd1_status], 0
@@:
cmp [cd_status], esi
jnz @f
call free_cd_channel
and [cd_status], 0
@@:
cmp [flp_status], esi
jnz @f
and [flp_status], 0
@@:
pop esi
cmp [bgrlockpid], esi
jnz @f
and [bgrlockpid], 0
and [bgrlock], 0
@@:
pusha ; remove all port reservations
mov edx, esi
shl edx, 5
add edx, CURRENT_TASK
mov edx, [edx+TASKDATA.pid]
rmpr0:
mov esi, [RESERVED_PORTS]
test esi, esi
jz rmpr9
rmpr3:
mov edi, esi
shl edi, 4
add edi, RESERVED_PORTS
cmp edx, [edi]
je rmpr4
dec esi
jnz rmpr3
jmp rmpr9
rmpr4:
mov ecx, 256
sub ecx, esi
shl ecx, 4
mov esi, edi
add esi, 16
cld
rep movsb
dec dword [RESERVED_PORTS]
jmp rmpr0
rmpr9:
popa
mov edi, esi ; do not run this process slot
shl edi, 5
mov [edi+CURRENT_TASK + TASKDATA.state], byte 9
; debugger test - terminate all debuggees
mov eax, 2
mov ecx, SLOT_BASE+2*0x100+APPDATA.debugger_slot
.xd0:
cmp eax, [TASK_COUNT]
ja .xd1
cmp dword [ecx], esi
jnz @f
and dword [ecx], 0
pushad
xchg eax, ecx
mov ebx, 2
call sys_system
popad
@@:
inc eax
add ecx, 0x100
jmp .xd0
.xd1:
; call systest
sti ; .. and life goes on
mov eax, [draw_limits.left]
mov ebx, [draw_limits.top]
mov ecx, [draw_limits.right]
mov edx, [draw_limits.bottom]
call calculatescreen
xor eax, eax
xor esi, esi
call redrawscreen
mov [MOUSE_BACKGROUND], byte 0; no mouse background
mov [DONT_DRAW_MOUSE], byte 0; draw mouse
and [application_table_status], 0
;mov esi,process_terminated
;call sys_msg_board_str
add esp, 4
ret
restore .slot
;iglobal
;if lang eq ru
; boot_sched_1 db '<27><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> GDT TSS 㪠<><E3AAA0><EFBFBD>',0
; boot_sched_2 db '<27><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> IDT ⠡<><E2A0A1><EFBFBD><EFBFBD>',0
;else
; boot_sched_1 db 'Building gdt tss pointer',0
; boot_sched_2 db 'Building IDT table',0
;end if
;endg
;build_scheduler:
; mov esi, boot_sched_1
; call boot_log
; call build_process_gdt_tss_pointer
; mov esi,boot_sched_2
; call boot_log
; ret
; Three following procedures are used to guarantee that
; some part of kernel code will not be terminated from outside
; while it is running.
; Note: they do not protect a thread from terminating due to errors inside
; the thread; accessing a nonexisting memory would still terminate it.
; First two procedures must be used in pair by thread-to-be-protected
; to signal the beginning and the end of an important part.
; It is OK to have nested areas.
; The last procedure must be used by outside wanna-be-terminators;
; if it is safe to terminate the given thread immediately, it returns eax=1;
; otherwise, it returns eax=0 and notifies the target thread that it should
; terminate itself when leaving a critical area (the last critical area if
; they are nested).
; Implementation. Those procedures use one dword in APPDATA for the thread,
; APPDATA.terminate_protection.
; * The upper bit is 1 during normal operations and 0 when terminate is requested.
; * Other bits form a number = depth of critical regions,
; plus 1 if the upper bit is 1.
; * When this dword goes to zero, the thread should be destructed,
; and the procedure in which it happened becomes responsible for destruction.
; Enter critical area. Called by thread which wants to be protected.
proc protect_from_terminate
mov edx, [current_slot]
; Atomically increment depth of critical areas and get the old value.
mov eax, 1
lock xadd [edx+APPDATA.terminate_protection], eax
; If the old value was zero, somebody has started to terminate us,
; so we are destructing and cannot do anything protected.
; Otherwise, return to the caller.
test eax, eax
jz @f
ret
@@:
; Wait for somebody to finish us.
call change_task
jmp @b
endp
; Leave critical area. Called by thread which wants to be protected.
proc unprotect_from_terminate
mov edx, [current_slot]
; Atomically decrement depth of critical areas.
lock dec [edx+APPDATA.terminate_protection]
; If the result of decrement is zero, somebody has requested termination,
; but at that moment we were inside a critical area; terminate now.
jz sys_end
; Otherwise, return to the caller.
ret
endp
; Request termination of thread identified by edx = SLOT_BASE + slot*256.
; Called by anyone.
proc request_terminate
xor eax, eax ; set return value
; Atomically clear the upper bit. If it was already zero, then
; somebody has requested termination before us, so just exit.
lock btr [edx+APPDATA.terminate_protection], 31
jnc .unsafe
; Atomically decrement depth of critical areas.
lock dec [edx+APPDATA.terminate_protection]
; If the result of decrement is nonzero, the target thread is inside a
; critical area; leave termination to leaving that area.
jnz .unsafe
; Otherwise, it is safe to kill the target now and the caller is responsible
; for this. Return eax=1.
inc eax
.unsafe:
ret
endp