WebSVN – Kolibri OS – Diff – /kernel/branches/Kolibri-acpi/blkdev/disk.inc



;; Copyright (C) KolibriOS team 2011. All rights reserved.      ;;
;; Distributed under terms of the GNU General Public License    ;;
;;                                                              ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

 

$Revision: 2257 $
 
; =============================================================================
; ================================= Constants =================================

; Driver flags. Represent bits in DISK.DriverFlags.
DISK_NO_INSERT_NOTIFICATION = 1
; Media flags. Represent bits in DISKMEDIAINFO.Flags.
DISK_MEDIA_READONLY = 1

 
; If too many partitions are detected,there is probably an error on the disk.
; 256 partitions should be enough for any reasonable use.
; Also, the same number is limiting the number of MBRs to process; if
; too many MBRs are visible,there probably is a loop in the MBR structure.

MAX_NUM_PARTITIONS = 256
 
; =============================================================================

; Optional, may be NULL.
; unsigned int adjust_cache_size(unsigned int suggested_size);
; Return value: 0 = disable cache, otherwise = used cache size in bytes.
ends

 
; This structure holds information on a medium.
; Objects with this structure are allocated by the kernel as a part of the DISK
; structure and are filled by a driver in the 'querymedia' callback.
struct DISKMEDIAINFO
.Flags		dd	?
; Combination of DISK_MEDIA_* bits.
.SectorSize	dd	?
; Size of the sector.
.Capacity	dq	?
; Size of the media in sectors.

ends
 
; This structure represents the disk cache. To follow the old implementation,
; there are two distinct caches for a disk, one for "system" data,and the other
; for "application" data.
struct DISKCACHE
.Lock		MUTEX

; Count of active references to the media object. One reference is kept during
; the lifetime of the media between two calls to 'disk_media_changed'.
; Another reference is taken during any filesystem operation for this media.
; The callback 'closemedia' is called when the reference count decrements to
; zero: this usually occurs in 'disk_media_changed', but can be delayed to the
; end of the last filesystem operation, if one is active.
.MediaInfo		DISKMEDIAINFO
; This field keeps information on the current media.
.NumPartitions	dd	?
; Number of partitions on this media.
.Partitions	dd	?
; Pointer to array of .NumPartitions pointers to PARTITION structures.
.cache_size	dd	?

	dd	disk_list
endg
uglobal
; This mutex guards all operations with the global list of DISK structures.
disk_list_mutex MUTEX
; * There are two dependent objects, a disk and a media. In the simplest case,
;   disk and media are both non-removable. However, in the general case both
;   can be removed at any time, simultaneously or only media,and this makes things
;   complicated.
; * For efficiency, both disk and media objects are located in the one
;   structure named DISK. However, logically they are different.
; * The following operations use data of disk object: adding (disk_add);
;   deleting (disk_del); filesystem (fs_lfn which eventually calls

	pop	eax
	call	malloc
; 1b. Check the result. If allocation failed, return (go to 9) with eax = 0.
	test	eax, eax
	jz	.nothing
; 2. Copy the disk name to the DISK structure.
; 2a. Get length of the name, including the terminating zero.
	mov	ebx, [esp+8+8]	; ebx = pointer to name
	push	eax		; save allocated pointer to DISK
	xor	eax, eax	; the argument of malloc() is in eax
@@:

; The default implementation of DISKFUNC.adjust_cache_size.
disk_default_adjust_cache_size:
	mov	eax, [esp+4]
	ret	4

 
; This is an internal function called from 'disk_media_changed' when a new media
; is detected. It creates the list of partitions for the media.
; If media is not partitioned, then the list consists of one partition which
; covers all the media.
; esi = pointer to the DISK structure.

	jnz	.mbr_failed
; 8. The MBR is treated differently from EBRs. For MBR we additionally need to
; execute step 9 and possibly step 10.
	test	ebp, ebp
	jnz	.mbr
; The partition table can be present or not present. In the first case, we just
; read the MBR. In the second case, we just read the bootsector for a
; filesystem.
; The following algorithm is used to distinguish between these cases.
; A. If at least one entry of the partition table is invalid, this is
;    a bootsector. See the description of 'is_partition_table_entry' for
;    definition of validity.
; B. If all entries are empty (filesystem type field is zero) and the first
;    byte is jmp opcode (0EBh or 0E9h), this is a bootsector which happens to
;    have zeros in the place of partition table.
; C. Otherwise, this is an MBR.
; 9. Test for MBR vs bootsector.
; 9a. Check entries. If any is invalid, go to 10 (rule A).
	call	is_partition_table_entry
	jc	.notmbr
	add	ecx, 10h

	cmp	byte [ebx], 0EBh
	jz	.notmbr
	cmp	byte [ebx], 0E9h
	jnz	.mbr
.notmbr:
; 10. This is not an  MBR. The media is not partitioned. Create one partition
; which covers all the media and abort the loop.
	stdcall disk_add_partition, 0, 0, \
		dword [esi+DISK.MediaInfo.Capacity], dword [esi+DISK.MediaInfo.Capacity+4]
	jmp	.done
.mbr:

Rev 2150	Rev 2268
Line 3...	Line 3...
3	;; Copyright (C) KolibriOS team 2011. All rights reserved. ;;	3	;; Copyright (C) KolibriOS team 2011. All rights reserved. ;;
4	;; Distributed under terms of the GNU General Public License ;;	4	;; Distributed under terms of the GNU General Public License ;;
5	;; ;;	5	;; ;;
6	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;	6	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
Line 7...	Line 7...
7		7
Line 8...	Line 8...
8	$Revision: 2140 $	8	$Revision: 2257 $
9		9
10	; =============================================================================	10	; =============================================================================
11	; ================================= Constants =================================	11	; ================================= Constants =================================
Line 19...	Line 19...
19	; Driver flags. Represent bits in DISK.DriverFlags.	19	; Driver flags. Represent bits in DISK.DriverFlags.
20	DISK_NO_INSERT_NOTIFICATION = 1	20	DISK_NO_INSERT_NOTIFICATION = 1
21	; Media flags. Represent bits in DISKMEDIAINFO.Flags.	21	; Media flags. Represent bits in DISKMEDIAINFO.Flags.
22	DISK_MEDIA_READONLY = 1	22	DISK_MEDIA_READONLY = 1
Line 23...	Line 23...
23		23
24	; If we see too many partitions, probably there is some error on the disk.	24	; If too many partitions are detected,there is probably an error on the disk.
25	; 256 partitions should be enough for any reasonable use.	25	; 256 partitions should be enough for any reasonable use.
26	; Also, the same number is limiting the number of MBRs to process; if we see	26	; Also, the same number is limiting the number of MBRs to process; if
27	; too many MBRs, probably there is a loop in the MBR structure.	27	; too many MBRs are visible,there probably is a loop in the MBR structure.
Line 28...	Line 28...
28	MAX_NUM_PARTITIONS = 256	28	MAX_NUM_PARTITIONS = 256
29		29
30	; =============================================================================	30	; =============================================================================
Line 83...	Line 83...
83	; Optional, may be NULL.	83	; Optional, may be NULL.
84	; unsigned int adjust_cache_size(unsigned int suggested_size);	84	; unsigned int adjust_cache_size(unsigned int suggested_size);
85	; Return value: 0 = disable cache, otherwise = used cache size in bytes.	85	; Return value: 0 = disable cache, otherwise = used cache size in bytes.
86	ends	86	ends
Line 87...	Line 87...
87		87
88	; This structure holds an information about a media.	88	; This structure holds information on a medium.
89	; Objects with this structure are allocated by the kernel as a part of DISK	89	; Objects with this structure are allocated by the kernel as a part of the DISK
90	; structure and filled by a driver in the 'querymedia' callback.	90	; structure and are filled by a driver in the 'querymedia' callback.
91	struct DISKMEDIAINFO	91	struct DISKMEDIAINFO
92	.Flags dd ?	92	.Flags dd ?
93	; Combination of DISK_MEDIA_* bits.	93	; Combination of DISK_MEDIA_* bits.
94	.SectorSize dd ?	94	.SectorSize dd ?
95	; Size of the sector.	95	; Size of the sector.
96	.Capacity dq ?	96	.Capacity dq ?
97	; Size of the media in sectors.	97	; Size of the media in sectors.
Line 98...	Line 98...
98	ends	98	ends
99		99
100	; This structure represents disk cache. To follow the old implementation,	100	; This structure represents the disk cache. To follow the old implementation,
101	; there are two distinct caches for a disk, one for "system" data, other	101	; there are two distinct caches for a disk, one for "system" data,and the other
102	; for "application" data.	102	; for "application" data.
103	struct DISKCACHE	103	struct DISKCACHE
104	.Lock MUTEX	104	.Lock MUTEX
Line 158...	Line 158...
158	; Count of active references to the media object. One reference is kept during	158	; Count of active references to the media object. One reference is kept during
159	; the lifetime of the media between two calls to 'disk_media_changed'.	159	; the lifetime of the media between two calls to 'disk_media_changed'.
160	; Another reference is taken during any filesystem operation for this media.	160	; Another reference is taken during any filesystem operation for this media.
161	; The callback 'closemedia' is called when the reference count decrements to	161	; The callback 'closemedia' is called when the reference count decrements to
162	; zero: this usually occurs in 'disk_media_changed', but can be delayed to the	162	; zero: this usually occurs in 'disk_media_changed', but can be delayed to the
163	; end of last filesystem operation, if one is active.	163	; end of the last filesystem operation, if one is active.
164	.MediaInfo DISKMEDIAINFO	164	.MediaInfo DISKMEDIAINFO
165	; This field keeps an information about the current media.	165	; This field keeps information on the current media.
166	.NumPartitions dd ?	166	.NumPartitions dd ?
167	; Number of partitions on this media.	167	; Number of partitions on this media.
168	.Partitions dd ?	168	.Partitions dd ?
169	; Pointer to array of .NumPartitions pointers to PARTITION structures.	169	; Pointer to array of .NumPartitions pointers to PARTITION structures.
170	.cache_size dd ?	170	.cache_size dd ?
Line 225...	Line 225...
225	dd disk_list	225	dd disk_list
226	endg	226	endg
227	uglobal	227	uglobal
228	; This mutex guards all operations with the global list of DISK structures.	228	; This mutex guards all operations with the global list of DISK structures.
229	disk_list_mutex MUTEX	229	disk_list_mutex MUTEX
230	; * There are two dependent objects, a disk and a media. In the simplest case	230	; * There are two dependent objects, a disk and a media. In the simplest case,
231	; disk and media are both non-removable. However, in the general case both	231	; disk and media are both non-removable. However, in the general case both
232	; can be removed at any time, simultaneously or only media, this makes things	232	; can be removed at any time, simultaneously or only media,and this makes things
233	; complicated.	233	; complicated.
234	; * For efficiency, both disk and media objects are located in the one	234	; * For efficiency, both disk and media objects are located in the one
235	; structure named DISK. However, logically they are different.	235	; structure named DISK. However, logically they are different.
236	; * The following operations use data of disk object: adding (disk_add);	236	; * The following operations use data of disk object: adding (disk_add);
237	; deleting (disk_del); filesystem (fs_lfn which eventually calls	237	; deleting (disk_del); filesystem (fs_lfn which eventually calls
Line 339...	Line 339...
339	pop eax	339	pop eax
340	call malloc	340	call malloc
341	; 1b. Check the result. If allocation failed, return (go to 9) with eax = 0.	341	; 1b. Check the result. If allocation failed, return (go to 9) with eax = 0.
342	test eax, eax	342	test eax, eax
343	jz .nothing	343	jz .nothing
344	; 2. Copy disk name to the DISK structure.	344	; 2. Copy the disk name to the DISK structure.
345	; 2a. Get length of the name, including the terminating zero.	345	; 2a. Get length of the name, including the terminating zero.
346	mov ebx, [esp+8+8] ; ebx = pointer to name	346	mov ebx, [esp+8+8] ; ebx = pointer to name
347	push eax ; save allocated pointer to DISK	347	push eax ; save allocated pointer to DISK
348	xor eax, eax ; the argument of malloc() is in eax	348	xor eax, eax ; the argument of malloc() is in eax
349	@@:	349	@@:
Line 625...	Line 625...
625	; The default implementation of DISKFUNC.adjust_cache_size.	625	; The default implementation of DISKFUNC.adjust_cache_size.
626	disk_default_adjust_cache_size:	626	disk_default_adjust_cache_size:
627	mov eax, [esp+4]	627	mov eax, [esp+4]
628	ret 4	628	ret 4
Line 629...	Line 629...
629		629
630	; This is an internal function called from 'disk_media_changed' when new media	630	; This is an internal function called from 'disk_media_changed' when a new media
631	; is detected. It creates the list of partitions for the media.	631	; is detected. It creates the list of partitions for the media.
632	; If media is not partitioned, then the list consists of one partition which	632	; If media is not partitioned, then the list consists of one partition which
633	; covers all the media.	633	; covers all the media.
634	; esi = pointer to the DISK structure.	634	; esi = pointer to the DISK structure.
Line 686...	Line 686...
686	jnz .mbr_failed	686	jnz .mbr_failed
687	; 8. The MBR is treated differently from EBRs. For MBR we additionally need to	687	; 8. The MBR is treated differently from EBRs. For MBR we additionally need to
688	; execute step 9 and possibly step 10.	688	; execute step 9 and possibly step 10.
689	test ebp, ebp	689	test ebp, ebp
690	jnz .mbr	690	jnz .mbr
691	; Partition table can be present or not present. In the first case, we just	691	; The partition table can be present or not present. In the first case, we just
692	; read the MBR. In the second case, we just read the bootsector for some	692	; read the MBR. In the second case, we just read the bootsector for a
693	; filesystem.	693	; filesystem.
694	; We use the following algorithm to distinguish between these cases.	694	; The following algorithm is used to distinguish between these cases.
695	; A. If at least one entry of the partition table is invalid, this is	695	; A. If at least one entry of the partition table is invalid, this is
696	; a bootsector. See the description of 'is_partition_table_entry' for	696	; a bootsector. See the description of 'is_partition_table_entry' for
697	; definition of validity.	697	; definition of validity.
698	; B. If all entries are empty (filesystem type field is zero) and the first	698	; B. If all entries are empty (filesystem type field is zero) and the first
699	; byte is jmp opcode (0EBh or 0E9h), this is a bootsector which happens to	699	; byte is jmp opcode (0EBh or 0E9h), this is a bootsector which happens to
700	; have zeros in the place of partition table.	700	; have zeros in the place of partition table.
701	; C. Otherwise, this is a MBR.	701	; C. Otherwise, this is an MBR.
702	; 9. Test for MBR vs bootsector.	702	; 9. Test for MBR vs bootsector.
703	; 9a. Check entries. If any is invalid, go to 10 (rule A).	703	; 9a. Check entries. If any is invalid, go to 10 (rule A).
704	call is_partition_table_entry	704	call is_partition_table_entry
705	jc .notmbr	705	jc .notmbr
706	add ecx, 10h	706	add ecx, 10h
Line 722...	Line 722...
722	cmp byte [ebx], 0EBh	722	cmp byte [ebx], 0EBh
723	jz .notmbr	723	jz .notmbr
724	cmp byte [ebx], 0E9h	724	cmp byte [ebx], 0E9h
725	jnz .mbr	725	jnz .mbr
726	.notmbr:	726	.notmbr:
727	; 10. This is not MBR. The media is not partitioned. Create one partition	727	; 10. This is not an MBR. The media is not partitioned. Create one partition
728	; which covers all the media and abort the loop.	728	; which covers all the media and abort the loop.
729	stdcall disk_add_partition, 0, 0, \	729	stdcall disk_add_partition, 0, 0, \
730	dword [esi+DISK.MediaInfo.Capacity], dword [esi+DISK.MediaInfo.Capacity+4]	730	dword [esi+DISK.MediaInfo.Capacity], dword [esi+DISK.MediaInfo.Capacity+4]
731	jmp .done	731	jmp .done
732	.mbr:	732	.mbr:

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(root)/kernel/branches/Kolibri-acpi/blkdev/disk.inc – Rev 2150 → 2268