support for PnP disks: add exports and docs

git-svn-id: svn://kolibrios.org@2120 a494cfbc-eb01-0410-851d-a64ba20cac60
This commit is contained in:
CleverMouse 2011-08-25 19:58:37 +00:00
parent 1eb4e63e51
commit cdeeb6be66
3 changed files with 88 additions and 3 deletions

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@ -85,6 +85,10 @@ iglobal
szStrchr db 'strchr',0
szStrrchr db 'strrchr',0
szDiskAdd db 'DiskAdd',0
szDiskDel db 'DiskDel',0
szDiskMediaChanged db 'DiskMediaChanged',0
align 16
kernel_export:
@ -160,6 +164,10 @@ kernel_export:
dd szStrchr , strchr
dd szStrrchr , strrchr
dd szDiskAdd , disk_add
dd szDiskDel , disk_del
dd szDiskMediaChanged, disk_media_changed
exp_lfb:
dd szLFBAddress , 0
dd 0 ;terminator, must be zero

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@ -0,0 +1,75 @@
All functions are stdcall unless mentioned otherwise.
=== Disk ===
The kernel exports the functions 'DiskAdd', 'DiskMediaChanged', 'DiskDel' for
drivers. They must be called in the following order: DiskAdd, then zero or
more DiskMediaChanged, then optionally DiskDel. The driver must not call
two functions in parallel, including two calls to DiskMediaChanged.
void* DiskAdd(DISKFUNC* functions, const char* name, void* userdata, int flags);
; The pointer 'functions' must be valid at least until the disk will be deleted
; (until DISKFUNC.close is called).
; The pointer 'name' can be invalid after this function returns.
; It should point to ASCIIZ-string without leading '/' in latin lowercase and
; digits, like 'usbhd0'.
; The value 'userdata' is any pointer-sized data, passed as is to all
; callbacks.
DISK_NO_INSERT_NOTIFICATION = 1
; The bitfield 'flags' has currently only one bit defined. If it is set, the
; driver will never call DiskMediaChanged(hDisk, true), so the kernel must scan
; for media insertion when the operation is requested.
struc DISKFUNC
{
.strucsize dd ?
.close dd ?
; void close(void* userdata);
; Optional.
; The last function that is called for the given disk. The kernel calls it when
; the kernel has finished all operations with the disk and it is safe to free
; all driver-specific data identified by 'userdata'.
.closemedia dd ?
; void closemedia(void* userdata);
; Optional.
; The kernel calls this function when it finished all processing with the
; current media. If media is removed, the driver should decline all requests
; to that media with DISK_STATUS_NO_MEDIA, even if new media is inserted,
; until this function is called. If media is removed, a new call to
; DiskMediaChanged(hDisk, true) is not allowed until this function is called.
.querymedia dd ?
; int querymedia(void* userdata, DISKMEDIAINFO* info);
; return value: 0 = success, otherwise = error
.read dd ?
; int read(void* userdata, void* buffer, __int64 startsector,
; int* numsectors);
; return value: 0 = success, otherwise = error
.write dd ?
; int write(void* userdata, const void* buffer, __int64 startsector,
; int* numsectors);
; Optional.
; return value: 0 = success, otherwise = error
.flush dd ?
; int flush(void* userdata);
; Optional.
; Flushes the hardware cache, if it exists. Note that a driver should not
; implement a software cache for read/write, since they are called from the
; kernel cache manager.
}
struc DISKMEDIAINFO
{
.flags dd ?
DISK_MEDIA_READONLY = 1
.sectorsize dd ?
.capacity dq ?
}
void DiskDel(void* hDisk);
; This function informs the kernel that the disk should be deleted from the
; system. This function removes the disk from the global file system; however,
; it is possible that active operations with the disk are still running. When
; the disk is actually removed, the kernel calls the 'close' function, which
; can free all device-related resources.
void DiskMediaChanged(void* hDisk, int newstate);
; This function informs the kernel that a media has been inserted, removed or
; changed. 'newstate' should be zero if currently there is no media inserted
; and nonzero in the other case. This function must not be called with nonzero
; 'newstate' from any of callbacks. This function must not be called if another
; call to this function is active.

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@ -633,10 +633,12 @@ lock dec [partition_buffer_users] ; no, we must allocate
; Note that 'read' callback operates with 64-bit sector numbers, so we must
; push additional zero as a high dword of sector number.
mov al, DISKFUNC.read
stdcall disk_call_driver, ebx, ebp, 0, 1
push 1
stdcall disk_call_driver, ebx, ebp, 0, esp
pop ecx
; 6. If the read has failed, abort the loop.
test eax, eax
jz .mbr_failed
dec ecx
jnz .mbr_failed
; 7. Check the MBR/EBR signature. If it is wrong, abort the loop.
; Soon we will access the partition table which starts at ebx+0x1BE,
; so we can fill its address right now. If we do it now, then the addressing