Subversion Repositories Kolibri OS

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;;                                                                 ;;

;; Copyright (C) KolibriOS team 2004-2015. All rights reserved.    ;;

;; Distributed under terms of the GNU General Public License       ;;

;;                                                                 ;;

;;  FAT functions for KolibriOS                                    ;;

;;                                                                 ;;

;;  Copyright 2002 Paolo Minazzi, paolo.minazzi@inwind.it          ;;

;;                                                                 ;;

;;  See file COPYING for details                                   ;;

;;  06.2015 fs_read64 - pathoswithin                            ;;

;;  04.02.2007 LFN create folder - diamond                         ;;

;;  08.10.2006 LFN delete file/folder - diamond                    ;;

;;  20.08.2006 LFN set file size (truncate/extend) - diamond       ;;

;;  17.08.2006 LFN write/append to file - diamond                  ;;

;;  23.06.2006 LFN start application - diamond                     ;;

;;  15.06.2006 LFN get/set file/folder info - diamond              ;;

;;  27.05.2006 LFN create/rewrite file - diamond                   ;;

;;  04.05.2006 LFN read folder - diamond                           ;;

;;  29.04.2006 Elimination of hangup after the                     ;;

;;             expiration hd_wait_timeout -  Mario79               ;;

;;  23.04.2006 LFN read file - diamond                             ;;

;;  28.01.2006 find all Fat16/32 partition in all input point      ;;

;;             to MBR, see file part_set.inc - Mario79             ;;

;;  15.01.2005 get file size/attr/date, file_append - ATV          ;;

;;  04.12.2004 skip volume label, file delete bug fixed - ATV      ;;

;;  29.11.2004 get_free_FAT changed, append dir bug fixed - ATV    ;;

;;  23.11.2004 don't allow overwrite dir with file - ATV           ;;

;;  18.11.2004 get_disk_info and more error codes - ATV            ;;

;;  17.11.2004 set_FAT/get_FAT and disk cache rewritten - ATV      ;;

;;  10.11.2004 removedir clear whole directory structure - ATV     ;;

;;  08.11.2004 rename - ATV                                        ;;

;;  30.10.2004 file_read return also dirsize in bytes - ATV        ;;

;;  20.10.2004 Makedir/Removedir - ATV                             ;;

;;  14.10.2004 Partition chain/Fat16 - ATV (thanks drh3xx)         ;;

;;  06.09.2004 Fix free space - Mario79                         ;;

;;  24.05.2004 Write back buffer for File_write - VT            ;;

;;  20.05.2004 File_read function to work with syscall 58 - VT  ;;

;;  30.03.2004 Error parameters at function return - VT         ;;

;;  29.06.2002 Improved fat32 verification - VT                 ;;

;;  20.05.2002 Hd status check - VT                             ;;

;;  01.05.2002 Bugfix in device write - VT                      ;;

;;                                                                 ;;

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cache_max equ 1919      ; max. is 1919*512+0x610000=0x6ffe00

PUSHAD_EAX equ [esp+28]

PUSHAD_ECX equ [esp+24]

PUSHAD_EDX equ [esp+20]

PUSHAD_EBX equ [esp+16]

PUSHAD_EBP equ [esp+8]

PUSHAD_ESI equ [esp+4]

PUSHAD_EDI equ [esp+0]

; Internal data for every FAT partition.

struct FAT PARTITION

fs_type              db ?

fat16_root           db 0       ; flag for fat16 rootdir

fat_change           db 0       ; 1=fat has changed

                     rb 1

Lock                 MUTEX ?    ; currently operations with one partition

; can not be executed in parallel since the legacy code is not ready

SECTORS_PER_FAT      dd 0x1f3a

NUMBER_OF_FATS       dd 0x2

SECTORS_PER_CLUSTER  dd 0x8

BYTES_PER_SECTOR     dd 0x200   ; Note: if BPS <> 512 need lots of changes

ROOT_CLUSTER         dd 2       ; first rootdir cluster

FAT_START            dd 0       ; start of fat table

ROOT_START           dd 0       ; start of rootdir (only fat16)

ROOT_SECTORS         dd 0       ; count of rootdir sectors (only fat16)

DATA_START           dd 0       ; start of data area (=first cluster 2)

LAST_CLUSTER         dd 0       ; last availabe cluster

ADR_FSINFO           dd 0       ; used only by fat32

fatRESERVED          dd 0x0FFFFFF6

fatBAD               dd 0x0FFFFFF7

fatEND               dd 0x0FFFFFF8

fatMASK              dd 0x0FFFFFFF

fatStartScan         dd 2

cluster_tmp          dd 0       ; used by analyze_directory

                                ; and analyze_directory_to_write

longname_sec1        dd 0       ; used by analyze_directory to save 2 previous

longname_sec2        dd 0       ; directory sectors for delete long filename

fat_in_cache         dd -1

; For FAT16/FAT32, this points to 512-byte buffer for the current sector of FAT.

; For FAT12, the entire FAT structure is read

; and unpacked from 12bit per cluster to word per cluster.

; Note: work with unpacked copy of FAT12 means

; additional memory and additional code for packing/unpacking.

; I'm not sure that the economy justifies the cost, but anyway,

; there is how work was done before my edits, and I'm just keeping the principle.

fat_cache_ptr        dd ?

fat12_unpacked_ptr   dd ?

buffer               rb 512

fsinfo_buffer        rb 512

ends

uglobal

align 4

partition_count      dd 0       ; partitions found by set_FAT32_variables

hd_error             dd 0

hd_setup             dd 0

hd_wait_timeout      dd 0

cache_search_start   dd 0       ; used by find_empty_slot

endg

uglobal

align 4

Sector512:      ; label for dev_hdcd.inc

buffer:

rb 512

endg

iglobal

align 4

fat_user_functions:

        dd      fat_free

        dd      (fat_user_functions_end - fat_user_functions - 4) / 4

        dd      fat_Read

        dd      fat_ReadFolder

        dd      fat_Rewrite

        dd      fat_Write

        dd      fat_SetFileEnd

        dd      fat_GetFileInfo

        dd      fat_SetFileInfo

        dd      0

        dd      fat_Delete

        dd      fat_CreateFolder

fat_user_functions_end:

endg

; these labels are located before the main function to make

; most of jumps to these be short

fat_create_partition.free_return0:

        mov     eax, ebp

        call    free

        pop     ebp

fat_create_partition.return0:

        xor     eax, eax

        ret

fat_create_partition:

; sector size must be 512

        cmp     dword [esi+DISK.MediaInfo.SectorSize], 512

        jnz     .return0

; bootsector must have been successfully read

        cmp     dword [esp+4], 0

        jnz     .return0

; bootsector signature must be correct

        cmp     word [ebx+0x1fe], 0xaa55

        jnz     .return0

; sectors per cluster must be nonzero

        cmp     byte [ebx+0xd], 0

        jz      .return0

; bytes per sector must be 0x200

        cmp     word [ebx+0xb], 0x200

        jnz     .return0

; number of fats must be nonzero

        cmp     byte [ebx+0x10], 0

        jz      .return0

; The only reason to be invalid partition now is FAT12. Since the test for

; FAT size requires knowledge of some calculated values, which are also used

; in the normal operation, let's hope for the best and allocate data now; if

; it will prove wrong, just deallocate it.

        movi    eax, sizeof.FAT

        call    malloc

        test    eax, eax

        jz      .return0

        mov     ecx, dword [ebp+PARTITION.FirstSector]

        mov     dword [eax+FAT.FirstSector], ecx

        mov     ecx, dword [ebp+PARTITION.FirstSector+4]

        mov     dword [eax+FAT.FirstSector+4], ecx

        mov     ecx, dword [ebp+PARTITION.Length]

        mov     dword [eax+FAT.Length], ecx

        mov     ecx, dword [ebp+PARTITION.Length+4]

        mov     dword [eax+FAT.Length+4], ecx

        mov     ecx, [ebp+PARTITION.Disk]

        mov     [eax+FAT.Disk], ecx

        mov     [eax+FAT.FSUserFunctions], fat_user_functions

        or      [eax+FAT.fat_in_cache], -1

        mov     [eax+FAT.fat_change], 0

        push    ebp

        mov     ebp, eax

        lea     ecx, [ebp+FAT.Lock]

        call    mutex_init

        movzx   eax, word [ebx+0xe]     ; sectors reserved

        mov     [ebp+FAT.FAT_START], eax

        movzx   eax, byte [ebx+0xd]     ; sectors per cluster

        mov     [ebp+FAT.SECTORS_PER_CLUSTER], eax

        movzx   ecx, word [ebx+0xb]     ; bytes per sector

        mov     [ebp+FAT.BYTES_PER_SECTOR], ecx

        movzx   eax, word [ebx+0x11]    ; count of rootdir entries (=0 fat32)

        shl     eax, 5                  ; mul 32

        dec     ecx

        add     eax, ecx                ; round up if not equal count

        inc     ecx                     ; bytes per sector

        xor     edx, edx

        div     ecx

        mov     [ebp+FAT.ROOT_SECTORS], eax     ; count of rootdir sectors

        movzx   eax, word [ebx+0x16]    ; sectors per fat <65536

        test    eax, eax

        jnz     @f

        mov     eax, [ebx+0x24]         ; sectors per fat

@@:

        mov     [ebp+FAT.SECTORS_PER_FAT], eax

        movzx   eax, byte [ebx+0x10]    ; number of fats

        mov     [ebp+FAT.NUMBER_OF_FATS], eax

        mul     [ebp+FAT.SECTORS_PER_FAT]

        test    edx, edx

        jnz     .free_return0

        add     eax, [ebp+FAT.FAT_START]

        jc      .free_return0

        mov     [ebp+FAT.ROOT_START], eax       ; rootdir = fat_start + fat_size * fat_count

        add     eax, [ebp+FAT.ROOT_SECTORS]     ; rootdir sectors should be 0 on fat32

        jc      .free_return0

        mov     [ebp+FAT.DATA_START], eax       ; data area = rootdir + rootdir_size

        movzx   eax, word [ebx+0x13]    ; total sector count <65536

        test    eax, eax

        jnz     @f

        mov     eax, [ebx+0x20]         ; total sector count

@@:

; total sector count must not exceed partition size

        cmp     dword [ebp+FAT.Length+4], 0