; ***************************************************************************** ; ; DRV_FAT.ASM [ TRDOS Kernel FAT12, FAT16, FAT32 FS Procedures ] ; Copyright (C) 2009 Erdogan TAN [11/07/2010] ; ; 06/06/2010 proc_get_last_cluster ; 18/04/2010 ; 28/02/2010 proc_update_cluster ; 27/09/2009 ; 23/09/2009 proc_get_next_cluster modif. ; ; 22/09/2009 proc_load_FAT_root_directory & proc_load_FAT_sub_directory modif. ; 20/09/2009 ; 05/09/2009 ; 23/08/2009 proc_load_FAT_root_directory ; 23/08/2009 proc_load_FAT_sub_directory ; ; 07/07/2009 proc_get_next_cluster ; ; TRDOS.ASM (include drv_fat.asm) ; ; ***************************************************************************** proc_get_next_cluster proc near ; 12/06/2010 -> BX:CX = Current (Previous) Cluster Retn ; 27/09/2009 fat sector limits check, bx (fat_buffer) > 0 check ; 23/09/2009 ; 07/07/2009 ; 2005 ; INPUT -> AX = Cluster Number, low 16 bit ; INPUT -> DX = Cluster Number, high 16 bit ; INPUT -> DS:SI = Logical Dos Drive Parameters Table ; OUTPUT -> clc -> No Error, DX:AX valid ; OUTPUT -> stc & AX=0 -> End Of Cluster Chain ; OUTPUT -> stc & AX>0 -> Error ; OUTPUT -> BX:CX = Current/Previous cluster if clc ; AX: Next Cluster Number, low 16 bit ; DX: Next Cluster Number, high 16 bit ; stc -> Error mov word ptr [FAT_CurrentCluster], ax mov word ptr [FAT_CurrentCluster]+2, dx ; 23/09/2009 mov bx, word ptr [FAT_Buffer] cmp bx, 0 ja short gnc_pass_allocate_FAT_buffer ;mov word ptr [FAT_BuffSector], bx ;mov word ptr [FAT_BuffSector]+2, bx ;mov byte ptr [FAT_BuffValidData], bx mov al, byte ptr [SI][LD_Name] mov byte ptr [FAT_BuffDrvName], al ; bx = 0 => Allocate the first free segment mov cx, 1536 ; FAT Buffer contains 3 FAT sectors mov ax, 0103h ; Buffer, AL= 3, FAT buffer allocation call proc_allocate_memory jc short loc_gnc_allocate_FAT_buffer_stc_retn mov word ptr [FAT_Buffer], bx push es mov es, bx xor ax, ax xor dx, dx jmp load_FAT_sectors3 loc_gnc_allocate_FAT_buffer_stc_retn: mov ax, 8 ; No space to allocate fat buffer ! mov dx, 0 retn gnc_pass_allocate_FAT_buffer: push es check_next_cluster_fat_type_0: ; 23/09/2009 ; mov bx, word ptr [FAT_Buffer] mov es, bx ; check_next_cluster_fat_type_1: cmp byte ptr [SI][LD_FATType], 2 jb short get_FAT12_next_cluster ja get_FAT32_next_cluster get_FAT16_next_cluster: mov bx, 300h ;768 div bx ; AX = Count of 3 FAT sectors ; DX = Cluster Offset shl dx, 1 ; Multiply by 2 mov bx, dx ; Byte Offset mov dx, 3 mul dx ; AX = FAT Sector ; DX = 0 mov cl, byte ptr [SI][LD_Name] cmp byte ptr [FAT_BuffValidData], 0 jna load_FAT_sectors0 cmp cl, byte ptr [FAT_BuffDrvName] jne load_FAT_sectors0 cmp ax, word ptr [FAT_BuffSector] jne load_FAT_sectors1 mov ax, word ptr ES:[BX] cmp al, 0F7h jb short loc_pass_gnc_FAT16_eoc_check cmp ah, 0Fh jb short loc_pass_gnc_FAT16_eoc_check ; 12/06/2010 jmp short loc_pass_gnc_FAT16_eoc_check_xor_ax_ax get_FAT12_next_cluster: mov bx, 400h ;1024 div bx ; AX = Count of 3 FAT sectors ; DX = Cluster Offset push ax mov ax, 3 mul dx ; Multiply by 3 shr ax, 1 ; Divide by 2 mov bx, ax ; Byte Offset pop ax mov dx, 3 mul dx ; AX = FAT Beginning Sector ; DX = 0 mov cl, byte ptr [SI][LD_Name] cmp byte ptr [FAT_BuffValidData], 0 jna load_FAT_sectors0 cmp cl, byte ptr [FAT_BuffDrvName] jne short load_FAT_sectors0 cmp ax, word ptr [FAT_BuffSector] jne short load_FAT_sectors1 mov ax, word ptr [FAT_CurrentCluster] shr ax, 1 mov ax, word ptr ES:[BX] jnc short get_FAT12_nc_even shr ax, 1 shr ax, 1 shr ax, 1 shr ax, 1 loc_gnc_fat12_eoc_check: cmp al, 0F7h jb short loc_pass_gnc_FAT16_eoc_check cmp ah, 0Fh jb short loc_pass_gnc_FAT16_eoc_check loc_pass_gnc_FAT16_eoc_check_xor_ax_ax: ; 12/06/2010 xor ax, ax loc_pass_gnc_FAT16_eoc_check: ; 12/06/2010 loc_pass_gnc_FAT32_eoc_check: ; 12/06/2010 mov cx, word ptr [FAT_CurrentCluster] mov bx, word ptr [FAT_CurrentCluster]+2 ; cmc pop es retn get_FAT12_nc_even: and ah,0Fh jmp short loc_gnc_fat12_eoc_check get_FAT32_next_cluster: mov cx, 180h ;384 call Rx_Dos_Div32 ; DX:AX = Count of 3 FAT sectors ; BX = Cluster Offset shl bx, 1 shl bx, 1 ; Multiply by 4 push bx mov bx, 3 call proc_mul32 pop bx ; Byte Offset ; DX:AX = FAT Sector mov cl, byte ptr [SI][LD_Name] cmp byte ptr [FAT_BuffValidData], 0 jna short load_FAT_sectors0 cmp cl, byte ptr [FAT_BuffDrvName] jne short load_FAT_sectors0 cmp dx, word ptr [FAT_BuffSector]+2 jne short load_FAT_sectors1 cmp ax, word ptr [FAT_BuffSector] jne short load_FAT_sectors2 mov ax, word ptr ES:[BX] mov dx, word ptr ES:[BX]+2 and dh, 0Fh ; 28 bit Cluster cmp al, 0F7h jb short loc_pass_gnc_FAT32_eoc_check cmp ah, 0FFh jb short loc_pass_gnc_FAT32_eoc_check cmp dx, 0FFFh jb short loc_pass_gnc_FAT32_eoc_check loc_pass_gnc_FAT32_eoc_check_xor_dx_dx: ; 12/06/2010 xor dx, dx jmp short loc_pass_gnc_FAT16_eoc_check_xor_ax_ax load_FAT_sectors0: mov byte ptr [FAT_BuffDrvName], cl load_FAT_sectors1: mov word ptr [FAT_BuffSector]+2, dx load_FAT_sectors2: mov word ptr [FAT_BuffSector], ax load_FAT_sectors3: add ax, word ptr [SI][LD_FATbegin] adc dx, word ptr [SI][LD_FATbegin]+2 cmp byte ptr [SI][LD_FATType], 2 ja short pass_FAT_load_scount_0 mov cx, word ptr [SI][LD_BPB][BPB_FATSz16] sub cx, word ptr [FAT_BuffSector] cmp cx, 3 jna short pass_FAT_load_scount_2 jmp short pass_FAT_load_scount_1 pass_FAT_load_scount_0: push ax push dx mov ax, word ptr [SI][LD_BPB][BPB_FATSz32] mov dx, word ptr [SI][LD_BPB][BPB_FATSz32]+2 sub ax, word ptr [FAT_BuffSector] sbb dx, word ptr [FAT_BuffSector]+2 ;jnc short pass_FAT_sector_negative_check ;pop dx ;pop ax ;xor cx, cx ;jmp short loc_FAT_sectors_load_error ;pass_FAT_sector_negative_check: cmp dx, 0 ja short pass_FAT32_load_scount cmp ax, 3 ja short pass_FAT32_load_scount mov cx, ax pop dx pop ax ;or cx, cx ;jz short loc_FAT_sectors_load_error jmp short pass_FAT_load_scount_2 pass_FAT32_load_scount: pop dx pop ax pass_FAT_load_scount_1: mov cx, 3 pass_FAT_load_scount_2: xor bx, bx call proc_disk_read jnc short pass_FAT_sectors_load_error mov byte ptr [FAT_BuffValidData], 0 loc_FAT_sectors_load_error: jmp short loc_pass_gnc_FAT32_eoc_check_xor_dx_dx pass_FAT_sectors_load_error: mov byte ptr [FAT_BuffValidData], 1 mov ax, word ptr [FAT_CurrentCluster] mov dx, word ptr [FAT_CurrentCluster]+2 jmp check_next_cluster_fat_type_1 proc_get_next_cluster endp proc_load_FAT_root_directory proc near ; 22/09/2009 ; 05/09/2009 ; 22/08/2009 ; INPUT -> ; DS:SI = DOS Drive Description Table ; OUTPUT -> STC = Root directory could not be loaded ; Error number is in AX (AL) ; BX = 0 (BX > 0 -> sectors are loaded but not all) ; DS:SI = DOS Drive Description Table ; CX = Directory buffer size in sectors ; NOTE: DirBuffer_Size is in bytes ! ; BX = Directory Buffer Segment xor ax, ax ; Error No. 0 = Not a valid FAT FS ;xor bh, bh mov bl, byte ptr [SI][LD_FATType] ;cmp bl, 1 ;jnb short loc_check_FAT12_FAT16 ;retn ;loc_check_FAT12_FAT16: mov bh, byte ptr [SI][LD_Name] ;cmp bl, 2 ; FAT12 = 1, FAT16 = 2, FAT32 = 3 ;ja short loc_plrd_FAT_xor_cmc_stc_retn1 mov cx, word ptr [SI][LD_BPB][RootDirEnts] ;or cx, cx ;jz short loc_plrd_FAT_xor_cmc_stc_retn2 cmp cx, 512 ;ja short loc_plrd_FAT_xor_cmc_stc_retn1 je short pass_plrd_movcx_512 ;cmp cx, 112 ; 224 ;jb short loc_plrd_FAT_xor_cmc_stc_retn1 mov ax, 32 ; Root dir entry size in bytes mul cx push cx ; Number of Root Dir Entries ;mov cx, word ptr [SI][LD_BPB][BytesPerSec] ;dec cx ;add ax, cx ;adc dx, 0 ;inc cx mov cx, 512 add ax, 511 div cx xchg cx, ax mul cx ; ax = Directy Buffer Size in bytes pop dx ; Number of Root Dir Entries dec dx ; Last entry number of root dir ; cx = Dir Buffer sector count jmp short loc_plrd_check_dir_buffer ;loc_plrd_FAT_xor_cmc_stc_retn1: ; xor cx, cx ;loc_plrd_FAT_xor_cmc_stc_retn2: ; xor bx, bx ; cmc ; retn pass_plrd_movcx_512: mov cx, 32 mov dx, 511 mov ax, 32*512 loc_plrd_check_dir_buffer: push cx ; Directory Buffer sector Count mov cx, ax ; Directory Buffer Size in bytes mov byte ptr [DirBuff_DRV], bh mov byte ptr [DirBuff_FATType], bl mov byte ptr [DirBuff_ValidData], 0 mov word ptr [DirBuff_LastEntry], dx mov word ptr [Dirbuff_Cluster], 0 mov word ptr [Dirbuff_Cluster]+2, 0 mov bx, word ptr [Directory_Buffer] ; Segment or bx, bx jz short pass_plrd_deallocate_dirbuff cmp word ptr [DirBuffer_Size], cx je short pass_plrd_reallocate_directory_buffer mov word ptr [DirBuffer_Size], cx mov ax, 0104h ;Consequently for 04h allocation call proc_deallocate_memory mov cx, word ptr [DirBuffer_Size] xor bx, bx mov word ptr [Directory_Buffer], bx ; 0 pass_plrd_deallocate_dirbuff: mov ax, 0104h ;Consequently allocate Directory Buffer call proc_allocate_memory jc short loc_plrd_dir_buff_alloc_err_1 mov word ptr [Directory_Buffer], bx pass_plrd_reallocate_directory_buffer: ; DS:SI = DOS Drive Description Table mov ax, word ptr [SI][LD_ROOTbegin] mov dx, word ptr [SI][LD_ROOTbegin]+2 pop cx ; Directory Buffer sector Count push cx push es mov es, bx xor bx, bx call proc_disk_read pop es mov bx, word ptr [Directory_Buffer] jnc short validate_RDirBuff_and_return pop ax ; pushed cx sub ax, cx or ax, ax jnz short pass_plrd_reset_bx xor bx, bx pass_plrd_reset_bx: mov cx, 15h ; DRV NOT READY OR READ ERROR ! xchg ax, cx ; CX = Number of loaded sectors stc retn validate_RDirBuff_and_return: pop cx mov byte ptr [DirBuff_ValidData], 1 xor ax, ax retn loc_plrd_dir_buff_alloc_err_1: pop cx mov ax, 8 ; NO SPACE TO ALLOCATE DIRECTORY BUFFER ! xor bx, bx stc retn proc_load_FAT_root_directory endp proc_load_FAT_sub_directory proc near ; 22/09/2009 ; 05/09/2009 ; 23/08/2009 ; INPUT -> ; DS:SI = DOS Drive Description Table ; DX:AX = Cluster Number ; OUTPUT -> STC = Sub directory could not be loaded ; Error number is in AX (AL) ; BX = 0 (BX > 0 -> sectors are loaded but not all) ; DS:SI = DOS Drive Description Table ; CX = Directory buffer size in sectors ; NOTE: DirBuffer_Size is in bytes ! ; BX = Directory Buffer Segment xor ch, ch mov cl, byte ptr [SI][LD_BPB][SecPerClust] ;or cl, cl ;jnz short loc_plsd_reset_dir_buff_decs ;xor bx, bx ;stc ;retn ;loc_plsd_reset_dir_buff_decs: mov byte ptr [DirBuff_ValidData], ch ; 0 mov word ptr [Dirbuff_Cluster], ax mov word ptr [Dirbuff_Cluster]+2, dx mov al, byte ptr [SI][LD_Name] mov ah, byte ptr [SI][LD_FATType] ;mov byte ptr [DirBuff_DRV], al ;mov byte ptr [DirBuff_FATType], ah mov word ptr [DirBuff_DRV], ax mov ax, word ptr [SI][LD_BPB][BytesPerSec] mul cx push ax mov cx, 32 ; Entry size in Bytes div cx dec ax pop cx mov word ptr [DirBuff_LastEntry], ax loc_plsd_check_dir_buffer: mov bx, word ptr [Directory_Buffer] or bx, bx jz short pass_plsd_deallocate_dirbuff cmp word ptr [DirBuffer_Size], cx je short pass_plsd_reallocate_directory_buffer mov word ptr [DirBuffer_Size], cx mov ax, 0104h ;Consequently for 04h allocation call proc_deallocate_memory mov cx, word ptr [DirBuffer_Size] xor bx, bx mov word ptr [Directory_Buffer], bx ; 0 pass_plsd_deallocate_dirbuff: mov ax, 0104h ;Consequently allocate Directory Buffer call proc_allocate_memory jc short loc_plsd_dir_buff_alloc_err_1 mov word ptr [Directory_Buffer], bx pass_plsd_reallocate_directory_buffer: ; DS:SI = DOS Drive Description Table mov ax, word ptr [DirBuff_Cluster] mov dx, word ptr [DirBuff_Cluster]+2 sub ax, 2 sbb dx, 0 push bx xor bh, bh mov bl, byte ptr [SI][LD_BPB][SecPerClust] mov cx, bx call proc_mul32 add ax, word ptr [SI][LD_DATAbegin] adc dx, word ptr [SI][LD_DATAbegin]+2 pop bx push cx push es mov es, bx xor bx, bx call proc_disk_read pop es mov bx, word ptr [Directory_Buffer] jnc short validate_SDirBuff_and_return pop ax sub ax, cx or ax, ax jnz short pass_plsd_reset_bx xor bx, bx pass_plsd_reset_bx: mov cx, 15h ; DRV NOT READY OR READ ERROR xchg ax, cx ; CX = Number of loaded sectors stc retn validate_SDirBuff_and_return: pop cx mov byte ptr [DirBuff_ValidData], 1 xor ax, ax retn loc_plsd_dir_buff_alloc_err_1: mov ax, 8 ; NO SPACE TO ALLOCATE DIRECTORY BUFFER xor bx, bx stc retn proc_load_FAT_sub_directory endp proc_update_cluster proc near ; 13/06/2010 loc_FAT_sectors_rw_error (common) ; 10/04/2010 ; 04/04/2010 ; 09/02/2005 ; INPUT -> AX = Cluster Number, low 16 bit ; INPUT -> DX = Cluster Number, high 16 bit ; INPUT -> BX = New Cluster Value, low 16 bit ; INPUT -> CX = New Cluster Value, high 16 bit ; INPUT -> DS:SI = Logical Dos Drive Parameters Table ; OUTPUT -> clc -> No Error, DX:AX valid ; OUTPUT -> stc & AX=0 -> End Of Cluster Chain ; OUTPUT -> stc & AX>0 -> Error ; AX: Next Cluster, low 16 bit ; DX: Next Cluster, high 16 bit ; BX: New Cluster Value, low 16 bit ; CX: New Cluster Value, high 16 bit ; stc -> Error mov word ptr [FAT_CurrentCluster], ax mov word ptr [FAT_CurrentCluster]+2, dx mov word ptr [ClusterValue], bx mov word ptr [ClusterValue]+2, cx ; 28/02/2010 ; 23/09/2009 mov bx, word ptr [FAT_Buffer] cmp bx, 0 ja short loc_update_cluster_check_fat_buffer ;mov word ptr [FAT_BuffSector], bx ;mov word ptr [FAT_BuffSector]+2, bx ;mov byte ptr [FAT_BuffValidData], bx mov al, byte ptr [SI][LD_Name] mov byte ptr [FAT_BuffDrvName], al ; bx = 0 => Allocate the first free segment mov cx, 1536 ; FAT Buffer contains 3 FAT sectors mov ax, 0103h ; Buffer, AL= 3, FAT buffer allocation call proc_allocate_memory jnc short loc_uc_allocate_FAT_buffer_stc_retn mov word ptr [FAT_Buffer], bx xor ax, ax xor dx, dx jmp load_uc_FAT_sectors_zero loc_uc_allocate_FAT_buffer_stc_retn: mov ax, 8 ; No space to allocate fat buffer ! mov dx, 0 retn loc_update_cluster_check_fat_buffer: ; 10/04/2010 push ax mov al, byte ptr [SI][LD_Name] cmp byte ptr [FAT_BuffDrvName], al je short loc_uc_check_fat_type_pop_ax cmp byte ptr [FAT_BuffValidData],1 ja loc_uc_save_fat_buffer_pop_ax jb short loc_uc_check_fat_type_reset_drvname mov byte ptr [FAT_BuffValidData],0 loc_uc_check_fat_type_reset_drvname: mov byte ptr [FAT_BuffDrvName], al loc_uc_check_fat_type_pop_ax: pop ax loc_update_cluster_check_fat_type: cmp byte ptr [SI][LD_FATType], 2 ja update_FAT32_cluster jb update_FAT12_cluster update_FAT16_cluster: cmp ax, 2 jb short return_uc_FAT_stc push word ptr [SI][LD_Clusters] pop word ptr [LastCluster] inc word ptr [LastCluster] cmp ax, word ptr [LastCluster] jna short pass_uc_fat16_errc return_uc_FAT_stc: xor ax, ax xor dx, dx stc retn pass_uc_fat16_errc: mov bx, 300h ;768 div bx ; AX = Count of 3 FAT sectors ; DX = Sector Offset shl dx, 1 ; Multiply by 2 push dx mov bx, 3 mul bx pop bx ; Sector Offset ; AX = FAT Sector ; DX = 0 cmp byte ptr [FAT_BuffValidData], 0 jna loc_uc_load_FAT_sectors cmp byte ptr [FAT_BuffValidData], 2 jne short loc_uc_check_fat16_buff_sector_load loc_uc_check_fat16_buff_sector_save: cmp ax, word ptr [FAT_BuffSector] jne short loc_uc_save_FAT_Buffer jmp short loc_update_fat16_cell loc_uc_check_fat16_buff_sector_load: cmp ax, word ptr [FAT_BuffSector] jne loc_uc_load_FAT_sectors loc_update_fat16_cell: push es mov ax, word ptr [FAT_Buffer] mov es, ax mov ax, word ptr ES:[BX] xor dx, dx mov word ptr [FAT_CurrentCluster], ax mov word ptr [FAT_CurrentCluster]+2, dx mov cx, word ptr [ClusterValue] mov word ptr ES:[BX],cx inc word ptr [FAT_ClusterCounter] mov byte ptr [FAT_BuffValidData], 2 pop es cmp ax, 2 jb short return_uc_FAT_stc cmp ax, word ptr [LastCluster] ja short return_uc_FAT_stc loc_fat_buffer_updated: mov cx, word ptr [ClusterValue]+2 loc_fat_buffer_updated_1: mov bx, word ptr [ClusterValue] clc retn loc_uc_save_fat_buffer_pop_ax: pop ax loc_uc_save_fat_buffer: call proc_save_fat_buffer jc short loc_FAT_sectors_rw_error mov byte ptr [FAT_BuffValidData], 1 mov ax, word ptr [FAT_CurrentCluster] mov dx, word ptr [FAT_CurrentCluster]+2 mov bx, word ptr [ClusterValue] mov cx, word ptr [ClusterValue]+2 jmp loc_update_cluster_check_fat_buffer loc_FAT_sectors_rw_error: mov byte ptr [FAT_BuffValidData], 0 ; mov ax, error code mov dx, 0 mov bx, word ptr [ClusterValue] mov cx, word ptr [ClusterValue]+2 retn update_FAT12_cluster: cmp ax, 2 jb return_uc_FAT_stc push word ptr [SI][LD_Clusters] pop word ptr [LastCluster] inc word ptr [LastCluster] cmp ax, word ptr [LastCluster] ja return_uc_FAT_stc mov bx, 400h ;1024 div bx ; AX = Count of 3 FAT sectors ; DX = Buffer Entry Offset push ax mov ax, 3 mul dx ; Multiply by 3 shr ax, 1 ; Divide by 2 mov dx, ax pop ax push dx mov bx, 3 mul bx pop bx ; Buffer Byte Offset ; AX = FAT Beginning Sector ; DX = 0 cmp byte ptr [FAT_BuffValidData], 0 jna loc_uc_load_FAT_sectors cmp byte ptr [FAT_BuffValidData], 2 jne short loc_uc_check_fat12_buff_sector_load loc_uc_check_fat12_buff_sector_save: cmp ax, word ptr [FAT_BuffSector] jne loc_uc_save_FAT_Buffer jmp short loc_update_fat12_cell loc_uc_check_fat12_buff_sector_load: cmp ax, word ptr [FAT_BuffSector] jne loc_uc_load_FAT_sectors loc_update_fat12_cell: push es mov cx, word ptr [FAT_Buffer] mov es, cx mov cx, word ptr [FAT_CurrentCluster] shr cx, 1 mov ax, word ptr ES:[BX] jnc short uc_FAT12_nc_even push ax and ax, 0Fh mov cx, word ptr [ClusterValue] shl cx, 1 shl cx, 1 shl cx, 1 shl cx, 1 or cx, ax pop ax mov word ptr ES:[BX],cx shr ax, 1 shr ax, 1 shr ax, 1 shr ax, 1 update_FAT12_buffer: pop es inc word ptr [FAT_ClusterCounter] mov word ptr [FAT_CurrentCluster], ax xor dx,dx mov word ptr [FAT_CurrentCluster]+2, dx mov byte ptr [FAT_BuffValidData], 2 cmp ax,2 jb return_uc_FAT_stc cmp ax, word ptr [LastCluster] ja return_uc_FAT_stc jmp loc_fat_buffer_updated uc_FAT12_nc_even: push ax and ax, 0F000h mov cx, word ptr [ClusterValue] and ch, 0Fh or cx, ax pop ax mov word ptr ES:[BX],cx and ah, 0Fh jmp short update_fat12_buffer update_FAT32_cluster: cmp dx,0 ja short pass_uc_FAT32_c_zero_check_1 cmp ax,2 jb return_uc_FAT_stc pass_uc_FAT32_c_zero_check_1: push word ptr [SI][LD_Clusters] pop word ptr [LastCluster] push word ptr [SI][LD_Clusters]+2 pop word ptr [LastCluster]+2 add word ptr [LastCluster],1 adc word ptr [LastCluster]+2,0 cmp dx, word ptr [LastCluster]+2 jb short pass_uc_fat32_errc ja return_uc_FAT_stc cmp ax, word ptr [LastCluster] ja return_uc_FAT_stc pass_uc_fat32_errc: mov cx, 180h ;384 call Rx_Dos_Div32 ; DX:AX = Count of 3 FAT sectors ; BX = Sector Offset shl bx, 1 shl bx, 1 ; Multiply by 4 push bx mov bx, 3 call proc_mul32 pop bx ; Sector Offset ; DX:AX = FAT Sector cmp byte ptr [FAT_BuffValidData], 0 jna loc_uc_load_FAT_sectors cmp byte ptr [FAT_BuffValidData], 2 je short loc_uc_check_fat32_buff_sector_load loc_uc_check_fat32_buff_sector_save: cmp ax, word ptr [FAT_BuffSector] jne loc_uc_save_FAT_Buffer cmp dx, word ptr [FAT_BuffSector]+2 jne loc_uc_save_FAT_Buffer jmp short loc_update_fat32_cell loc_uc_check_fat32_buff_sector_load: cmp ax, word ptr [FAT_BuffSector] jne short loc_uc_load_FAT_sectors cmp dx, word ptr [FAT_BuffSector]+2 jne short loc_uc_load_FAT_sectors loc_update_fat32_cell: push es mov ax, word ptr [FAT_Buffer] mov es, bx mov ax, word ptr ES:[BX] mov dx, word ptr ES:[BX]+2 and dh, 0Fh ; 28 bit Cluster mov word ptr [FAT_CurrentCluster], ax mov word ptr [FAT_CurrentCluster]+2, dx mov cx, word ptr [ClusterValue] mov word ptr ES:[BX],cx mov cx, word ptr [ClusterValue]+2 mov word ptr ES:[BX]+2,cx add word ptr [FAT_ClusterCounter],1 adc word ptr [FAT_ClusterCounter]+2,0 mov byte ptr [FAT_BuffValidData], 2 pop es cmp dx,0 ja short pass_uc_FAT32_c_zero_check_2 cmp ax,2 jb return_uc_FAT_stc pass_uc_FAT32_c_zero_check_2: cmp dx, word ptr [LastCluster]+2 jb loc_fat_buffer_updated_1 ja return_uc_FAT_stc cmp ax, word ptr [LastCluster] ja return_uc_FAT_stc jmp loc_fat_buffer_updated_1 loc_uc_load_FAT_sectors: mov word ptr [FAT_BuffSector]+2, dx mov word ptr [FAT_BuffSector], ax load_uc_FAT_sectors_zero: add ax, word ptr [SI][LD_FATbegin] adc dx, word ptr [SI][LD_FATbegin]+2 push es mov bx, word ptr [FAT_Buffer] mov es, bx xor bx, bx mov cx, 3 call proc_disk_read pop es jc loc_FAT_sectors_rw_error mov byte ptr [FAT_BuffValidData], 1 mov ax, word ptr [FAT_CurrentCluster] mov dx, word ptr [FAT_CurrentCluster]+2 mov bx, word ptr [ClusterValue] mov cx, word ptr [ClusterValue]+2 jmp loc_update_cluster_check_fat_type ClusterValue: dd 0 proc_update_cluster endp proc_save_FAT_buffer proc near ; 18/04/2010 ; 10/04/2010 ; 28/02/2010 ; 09/02/2005 ; INPUT: None ; OUTPUT: stc -> error code in AL ; AX, DX, CX, BX is modified ; 10/04/2010 ; ; ; mov cx, 0FFh (if stc then check cx) ; mov bx, word ptr [FAT_Buffer] ;or bx, bx ;jz short loc_save_fat_buffer_id_stc_retn xor dl, dl mov ah, byte ptr [FAT_BuffDrvName] mov dh, ah sub dh, 'A' ;jc short loc_save_fat_buffer_id_stc_retn ;cmp byte ptr [FAT_BuffValidData], bl ;0 ;jna short loc_save_fat_buffer_id_stc_retn push si mov si, offset Logical_DOSDisks add si, dx ; mov ax, word ptr [FAT_BuffSector] cmp byte ptr [SI][LD_FATType], 2 ja short loc_save_fat32_buff xor dh, dh mov cx, word ptr [SI][LD_BPB][FATSecs] sub cx, ax cmp cx, 3 jna short loc_save_fat_buff_cont jmp short pass_save_fat_buff_remain_sectors_3 ;loc_save_fat_buffer_id_stc_retn: ; mov ax, 0Dh ; Invalid DATA ! ; stc ; retn loc_save_fat32_buff: mov dx, word ptr [FAT_BuffSector]+2 mov bx, Word Ptr [SI][LD_BPB][FAT32_FAT_Size]+2 mov cx, Word Ptr [SI][LD_BPB][FAT32_FAT_Size] sub cx, ax sbb bx, dx cmp bx, 0 ja short pass_save_fat_buff_remain_sectors_3 cmp cx, 3 jna short loc_save_fat_buff_cont pass_save_fat_buff_remain_sectors_3: mov cx, 3 loc_save_fat_buff_cont: ; 18/04/2010 mov bx, word ptr [FAT_Buffer] add ax, word ptr [SI][LD_FATbegin] adc dx, word ptr [SI][LD_FATbegin]+2 mov es, bx xor bx, bx push cx call proc_disk_write pop cx push ds pop es jc short loc_save_FAT_buff_write_err cmp byte ptr [SI][LD_FATType], 2 jna short pass_calc_2nd_fat32_addr mov ax, Word Ptr [SI][LD_BPB][FAT32_FAT_Size] mov dx, Word Ptr [SI][LD_BPB][FAT32_FAT_Size]+2 jmp short pass_calc_2nd_fat_addr pass_calc_2nd_fat32_addr: mov ax, word ptr [SI][LD_BPB][FATSecs] xor dx, dx pass_calc_2nd_fat_addr: add ax, word ptr [SI][LD_FATbegin] adc dx, word ptr [SI][LD_FATbegin]+2 add ax, word ptr [FAT_BuffSector] adc dx, word ptr [FAT_BuffSector]+2 mov bx, word ptr [FAT_Buffer] mov es, bx xor bx, bx call proc_disk_write push ds pop es jc short loc_save_FAT_buff_write_err mov byte ptr [FAT_BuffValidData], 1 ; Valid (but do not save) loc_save_FAT_buff_write_err: ; 10/04/2010 pop si retn proc_save_FAT_buffer endp proc_calculate_FAT_freespace proc near ; 10/04/2010 BugFix ; 03/04/2010 modification ; 2005 ; ; INPUT: DX:AX = Cluster count to be added or subtracted ; If BH = FFh, DS:SI = TR-DOS Logical Drive Description Table ; If BH < FFh, BH = TR-DOS Logical Drive Number ; BL: 0= Calculate, 1= Add, 2= Subtract, 3= Get (Not Set/Calc) ; OUTPUT: DX:AX = Free Space in sectors ; SI= Logical Dos Drive Table Offset ; BH= Logical Dos Drive Number (same with input value of BH) ; BL= Performed operation (same with input value of BL) ; CX = 0 -> no error ; 10/04/2010 mov word ptr [CFS_OPType], bx mov word ptr [CFS_CC], ax mov word ptr [CFS_CC]+2, dx cmp bh, 0FFh je short pass_calculate_freespace_get_drive_dt_offset mov ah, bh xor al, al mov si, offset Logical_DOSdisks add si, ax pass_calculate_freespace_get_drive_dt_offset: cmp bl, 3 jae loc_get_free_sectors cmp byte ptr [SI][LD_FATType], 2 jna short loc_set_fcc mov ax, word ptr [SI][LD_StartSector] mov dx, word ptr [SI][LD_StartSector]+2 add ax, word ptr [SI][LD_BPB][FAT32_FSInfoSec] adc dx, 0 mov word ptr [CFS_FAT32FSINFOSEC], ax mov word ptr [CFS_FAT32FSINFOSEC]+2, dx ; 10/04/2010 ; cmp bl, 0 or bl, bl jz short loc_reset_fcc ; jmp short loc_set_free_sectors jmp loc_update_FAT32_fs_info_fcc loc_set_fcc: ;cmp bl, 0 or bl, bl jz short loc_reset_fcc ; 10/04/2010 mov ax, word ptr [SI][LD_FreeSectors] mov dx, word ptr [SI][LD_FreeSectors]+2 mov cl, byte ptr [SI][LD_BPB][SecPerClust] ; cmp cl, 1 ; jna short pass_set_fcc_div32 xor ch, ch call Rx_Dos_Div32 ; or bx, bx ; ; BX -> Remain sectors < SecPerClust ; ; BX > 0 -> invalid free sector count ; jnz short loc_reset_fcc ; or dx, dx ; jnz short loc_reset_fcc ;pass_set_fcc_div32: mov word ptr [FreeClusterCount], ax ; mov word ptr [FreeClusterCount]+2, dx jmp loc_set_free_sectors_FAT12_FAT16 loc_get_free_sectors: mov ax, word ptr [SI][LD_FreeSectors] mov dx, word ptr [SI][LD_FreeSectors]+2 xor cx, cx retn loc_reset_fcc: ; 03/04/2010 xor ax, ax mov word ptr [FreeClusterCount], ax ; 0 mov word ptr [FreeClusterCount]+2, ax ; 0 push word ptr [SI][LD_Clusters] pop word ptr [LastCluster] push word ptr [SI][LD_Clusters]+2 pop word ptr [LastCluster]+2 add word ptr [LastCluster],1 adc word ptr [LastCluster]+2, ax ; 0 cmp byte ptr [SI][LD_FATType],2 jna short loc_count_free_fat_clusters_0 dec ax ; FFFFh mov word ptr [CFS_FAT32FC], ax ;FFFFh mov word ptr [CFS_FAT32FC]+2, ax ;FFFFh mov ax, 2 mov dx, 0 loc_count_fc_next_cluster_0: push ax push dx call proc_get_next_cluster jnc short loc_check_fat32_ff_cluster cmp ax, 0 ja short loc_put_fcc_unknown_sign cmp dx, 0 jna short pass_inc_cfs_fcc_0 loc_put_fcc_unknown_sign: pop dx pop ax ; "Free count is Unknown" sign mov word ptr [FreeClusterCount], 0FFFFh mov word ptr [FreeClusterCount]+2, 0FFFFh jmp loc_update_FAT32_fs_info_fcc loc_check_fat32_ff_cluster: cmp ax, 0 ja short pass_inc_cfs_fcc_0 cmp dx, 0 ja short pass_inc_cfs_fcc_0 pop dx pop ax mov word ptr [CFS_FAT32FC], ax mov word ptr [CFS_FAT32FC]+2, dx mov word ptr [FreeClusterCount], 1 jmp short pass_inc_cfs_fcc_1 pass_inc_cfs_fcc_0: pop dx pop ax pass_inc_cfs_fcc_0c: add ax,1 adc dx,0 cmp dx, word ptr [LastCluster]+2 jb short loc_count_fc_next_cluster_0 ja loc_update_FAT32_fs_info_fcc cmp ax, word ptr [LastCluster] jna short loc_count_fc_next_cluster_0 jmp loc_update_FAT32_fs_info_fcc loc_count_free_fat_clusters_0: mov ax, 2 mov dx, 0 loc_count_fc_next_cluster: push ax push dx call proc_get_next_cluster jnc short loc_count_free_clusters_1 cmp ax, 0 ja short loc_count_fcc_stc cmp dx, 0 jna short pass_inc_cfs_fcc loc_count_fcc_stc: pop dx pop ax ; "Free count is Unknown" sign mov word ptr [FreeClusterCount], 0FFFFh mov word ptr [FreeClusterCount]+2, 0FFFFh jmp loc_update_FAT32_fs_info_fcc loc_count_free_clusters_1: cmp ax, 0 ja short pass_inc_cfs_fcc cmp dx, 0 ja short pass_inc_cfs_fcc add word ptr [FreeClusterCount],1 adc word ptr [FreeClusterCount]+2,0 pass_inc_cfs_fcc: pop dx pop ax pass_inc_cfs_fcc_1: add ax,1 adc dx,0 cmp dx, word ptr [LastCluster]+2 jb short loc_count_fc_next_cluster ja short loc_set_free_sectors cmp ax, word ptr [LastCluster] jna short loc_count_fc_next_cluster loc_set_free_sectors: cmp byte ptr [SI][LD_FATType], 2 ja short loc_update_FAT32_fs_info_fcc loc_set_free_sectors_FAT12_FAT16: cmp byte ptr [CFS_OPtype], 0 jna short pass_FAT_add_sub_fcc mov ax, word ptr [CFS_CC] cmp byte ptr [CFS_OPtype], 1 ja short pass_FAT_add_fcc add word ptr [FreeClusterCount], ax jmp short pass_FAT_add_sub_fcc pass_FAT_add_fcc: sub word ptr [FreeClusterCount], ax pass_FAT_add_sub_fcc: xor ah, ah mov al, byte ptr [SI][LD_BPB][SecPerClust] mov dx, word ptr [FreeClusterCount] mul dx loc_cfs_retn_params: mov word ptr [SI][LD_FreeSectors], ax mov word ptr [SI][LD_FreeSectors]+2, dx mov bx, word ptr [CFS_OPType] or cx, cx retn loc_update_FAT32_fs_info_fcc: mov ax, word ptr [CFS_FAT32FSINFOSEC] mov dx, word ptr [CFS_FAT32FSINFOSEC]+2 ;push ds ;pop es mov bx, offset DOSBootSectorBuff mov cx, 1 call proc_disk_read jnc short loc_check_fcc_FSINFO_signs loc_put_fcc_invalid_sign: mov word ptr [FreeClusterCount], 0FFFFh mov word ptr [FreeClusterCount]+2, 0FFFFh jmp loc_set_FAT32_free_sectors loc_check_fcc_FSINFO_signs: cmp word ptr [DOSBootSectorBuff], 5252h jne short loc_put_fcc_invalid_sign cmp word ptr [DOSBootSectorBuff]+2, 4161h jne short loc_put_fcc_invalid_sign mov bx, offset DOSBootSectorBuff add bx, 484 cmp word ptr [BX], 7272h jne short loc_put_fcc_invalid_sign cmp word ptr [BX]+2, 6141h jne short loc_put_fcc_invalid_sign add bx, 4 cmp byte ptr [CFS_OPtype], 0 jna short pass_FAT32_add_sub_fcc_0 mov ax, word ptr [BX] mov dx, word ptr [BX]+2 cmp byte ptr [CFS_OPtype], 1 ja short pass_FAT32_add_fcc add ax, word ptr [CFS_CC] adc dx, word ptr [CFS_CC]+2 mov word ptr [FreeClusterCount], ax mov word ptr [FreeClusterCount]+2, dx ; Folllowing "FFFFFFFFh" replacement is a sign ; for the first free cluster reset, later ; This is only for bl=1 status (after deleting a file) mov word ptr [BX]+4, 0FFFFh ; Next free Cluster Low Word mov word ptr [BX]+6, 0FFFFh ; Next free Cluster High Word jmp short pass_FAT32_add_sub_fcc pass_FAT32_add_fcc: sub ax, word ptr [CFS_CC] sbb dx, word ptr [CFS_CC]+2 mov word ptr [FreeClusterCount], ax mov word ptr [FreeClusterCount]+2, dx jmp short pass_FAT32_add_sub_fcc pass_FAT32_add_sub_fcc_0: push word ptr [CFS_FAT32FC] pop word ptr [BX]+4 push word ptr [CFS_FAT32FC]+2 pop word ptr [BX]+6 pass_FAT32_add_sub_fcc: push word ptr [FreeClusterCount] pop word ptr [BX] push word ptr [FreeClusterCount]+2 pop word ptr [BX]+2 mov ax, word ptr [CFS_FAT32FSINFOSEC] mov dx, word ptr [CFS_FAT32FSINFOSEC]+2 ;push ds ;pop es mov bx, offset DOSBootSectorBuff mov cx, 1 call proc_disk_write jnc short loc_set_FAT32_free_sectors ; If Free Cluster Count = FFFFFFFFh, it is INVALID/UNKNOWN ; That is an error sign which will be checked/corrected later mov word ptr [FreeClusterCount], 0FFFFh mov word ptr [FreeClusterCount]+2, 0FFFFh loc_set_FAT32_free_sectors: xor bh, bh mov bl, byte ptr [SI][LD_BPB][SecPerClust] mov ax, word ptr [FreeClusterCount] mov dx, word ptr [FreeClusterCount]+2 call proc_mul32 jmp loc_cfs_retn_params CFS_OPType: db 0 CFS_Drv: db 0 CFS_CC: dd 0 CFS_FAT32FSINFOSEC: dd 0 CFS_FAT32FC: dd 0 proc_calculate_FAT_freespace endp proc_get_last_cluster proc near ; 12/06/2010 BX:CX -> previous cluster retn ; 06/06/2010 ; INPUT -> AX = First Cluster Number, low 16 bit ; INPUT -> DX = First Cluster Number, high 16 bit ; INPUT -> DS:SI = Logical Dos Drive Parameters Table ; OUTPUT -> clc -> No Error, DX:AX valid ; OUTPUT -> stc & AX>0 -> Error ; AX: Last Cluster Number, low 16 bit ; DX: Last Cluster Number, high 16 bit ; stc -> Error mov cx, ax mov bx, dx loc_glc_get_next_cluster_1: mov word ptr [glc_prevcluster], cx mov word ptr [glc_prevcluster]+2, bx loc_glc_get_next_cluster_2: call proc_get_next_cluster ; cx:bx = previous cluster ; dx:ax = the last cluster jnc short loc_glc_get_next_cluster_1 or ax, ax jnz short loc_glc_stc_retn ; cx:bx = previous Cluster mov dx, bx mov ax, cx loc_glc_prev_cluster_retn: mov cx, word ptr [glc_prevcluster] mov bx, word ptr [glc_prevcluster]+2 retn loc_glc_stc_retn: cmc ;stc jmp short loc_glc_prev_cluster_retn ;12/06/2010 glc_prevcluster: dd 0 proc_get_last_cluster endp proc_get_first_free_cluster proc near ; 10/07/2010 ; INPUT -> DS:SI = DOS Drive Description Table ; OUTPUT -> ES=DS ; stc -> Error code in AL ; clc -> DX:AX = FFFFFFFFh if no free space ; BX = FAT32 FSI sector buffer address if > 0 ; DX:AX >= 0 and DX:AX < FFFFFFFFh is valid ; but DX:AX >= 2 is expected for FAT/FAT32 push ds pop es ; 11/07/2010 mov ax, word ptr [SI][LD_Clusters] mov dx, word ptr [SI][LD_Clusters]+2 add ax, 1 adc dx, 0 mov word ptr [gffc_last_free_cluster], ax mov word ptr [gffc_last_free_cluster]+2, dx ; xor ax, ax xor dx, dx cmp byte ptr [SI][LD_FATType], 2 jna short loc_gffc_get_first_fat_free_cluster mov ax, word ptr [SI][LD_StartSector] mov dx, word ptr [SI][LD_StartSector]+2 add ax, word ptr [SI][LD_BPB][BPB_FSInfo] adc dx, 0 mov bx, offset DOSBootSectorBuff call proc_disk_read jnc short loc_gffc_check_fsinfo_signs retn_gffc_get_fsinfo_sec: retn retn_gffc_get_fsinfo_stc: ; 11/07/2010 xor bx, bx ; xor dx, dx mov ax, 0Bh ; Invalid format stc retn loc_gffc_check_FSINFO_signs: cmp word ptr [DOSBootSectorBuff], 5252h jne short retn_gffc_get_fsinfo_stc cmp word ptr [DOSBootSectorBuff]+2, 4161h jne short retn_gffc_get_fsinfo_stc ;mov bx, offset DOSBootSectorBuff add bx, 484 cmp word ptr [BX], 7272h jne short retn_gffc_get_fsinfo_stc cmp word ptr [BX]+2, 6141h jne short retn_gffc_get_fsinfo_stc add bx, 8 ; FSI_Next_Free push word ptr [BX] pop ax push word ptr [BX]+2 pop dx ;DX:AX = First free cluster ;(from FAT 32 FS Info sector) xor bx, bx ; 0 dec bx ;FFFFh cmp dx, bx jb short loc_gffc_get_first_fat32_free_cluster cmp ax, bx jb short loc_gffc_get_first_fat32_free_cluster inc dx ; 0 inc ax ; 0 inc ax ; 1 inc ax ; 2 loc_gffc_get_first_fat32_free_cluster: loc_gffc_get_first_fat_free_cluster: mov word ptr [gffc_first_free_cluster], ax mov word ptr [gffc_first_free_cluster]+2, dx mov word ptr [gffc_next_free_cluster], ax mov word ptr [gffc_next_free_cluster]+2, dx loc_gffc_loop_get_next_cluster: call proc_get_next_cluster jnc short loc_gffc_first_free_fat_cluster_cont or ax, ax jz short loc_gffc_first_free_fat_cluster_next cmc retn loc_gffc_first_free_fat_cluster_cont: cmp ax, 0 ja short loc_gffc_first_free_fat_cluster_next cmp dx, 0 ja short loc_gffc_first_free_fat_cluster_next mov dx, bx mov ax, cx jmp short loc_gffc_check_for_set loc_gffc_first_free_fat_cluster_next: mov ax, word ptr [gffc_next_free_cluster] mov dx, word ptr [gffc_next_free_cluster]+2 cmp dx, word ptr [gffc_last_free_cluster]+2 ja short retn_stc_from_get_first_free_cluster jb short pass_gffc_last_cluster_ax_check cmp ax, word ptr [gffc_last_free_cluster] jnb short retn_stc_from_get_first_free_cluster pass_gffc_last_cluster_ax_check: add ax, 1 adc dx, 0 mov word ptr [gffc_next_free_cluster], ax mov word ptr [gffc_next_free_cluster]+2, dx jmp short loc_gffc_loop_get_next_cluster retn_stc_from_get_first_free_cluster: mov ax, word ptr [gffc_first_free_cluster] mov dx, word ptr [gffc_first_free_cluster]+2 cmp dx, 0 ja short loc_gffc_check_previous_clusters cmp ax, 2 ja short loc_gffc_check_previous_clusters ; xor dx, dx ; 0 dec dx mov ax, dx ; FFFFh loc_gffc_check_for_set: cmp byte ptr [SI][LD_FATType], 3 jnb short loc_gffc_set_first_fat32_cluster_1 xor bx, bx retn loc_gffc_set_first_fat32_cluster_1: mov bx, offset DOSBootSectorBuff cmp ax, word ptr [BX]+492 ; FSI_Next_Free jne short loc_gffc_set_first_fat32_cluster_2 cmp dx, word ptr [BX]+494 je short retn_gffc_set_first_fat32_cluster loc_gffc_set_first_fat32_cluster_2: call proc_set_first_free_cluster retn_gffc_set_first_fat32_cluster: retn loc_gffc_check_previous_clusters: ; 11/07/2010 sub ax, 1 sbb dx, 0 mov word ptr [gffc_last_free_cluster], ax mov word ptr [gffc_last_free_cluster]+2, dx mov ax, 2 xor dx, dx jmp loc_gffc_get_first_fat_free_cluster gffc_next_free_cluster: dd 0 gffc_first_free_cluster: dd 0 gffc_last_free_cluster: dd 0 proc_get_first_free_cluster endp proc_set_first_free_cluster proc near ; 10/07/2010 -> only for FAT32 file system ; INPUT -> DS:SI = DOS Drive Description Table ; ES=DS ; DX:AX = First cluster ; IF BX > 0 it isn FSINFO sector buffer address ; BX must be 0 is FSINFO sector is not loaded ; ; OUTPUT-> DS:SI = DOS Drive Description Table ; ES=DS ; IF BX > 0 it is FSINFO sector buffer address ; BX is 0 if FSINFO sector could not be loaded ; stc -> Error code in AL ; clc -> first free cluster is succelfully updated or bx, bx jnz short loc_sffc_check_FSINFO_signs_2 cmp byte ptr [SI][LD_FATType], 3 jnb short loc_sffc_read_fsinfo_sector mov ax, 0Fh ; MSDOS Error : Invalid drive retn loc_sffc_read_fsinfo_sector: push ax push dx mov ax, word ptr [SI][LD_StartSector] mov dx, word ptr [SI][LD_StartSector]+2 add ax, word ptr [SI][LD_BPB][BPB_FSInfo] adc dx, 0 mov bx, offset DOSBootSectorBuff mov cx, 1 call proc_disk_read pop dx jnc short loc_sffc_check_fsinfo_signs_1 pop dx mov bx, 0 retn loc_sffc_check_FSINFO_signs_1: pop ax loc_sffc_check_FSINFO_signs_2: cmp word ptr [BX], 5252h jne short retn_sffc_get_fsinfo_stc cmp word ptr [BX]+2, 4161h jne short retn_sffc_get_fsinfo_stc cmp word ptr [BX]+484, 7272h jne short retn_sffc_get_fsinfo_stc cmp word ptr [BX]+486, 6141h jne short retn_sffc_get_fsinfo_stc mov word ptr [BX]+492, ax mov word ptr [BX]+494, dx mov ax, word ptr [SI][LD_StartSector] mov dx, word ptr [SI][LD_StartSector]+2 add ax, word ptr [SI][LD_BPB][BPB_FSInfo] adc dx, 0 ;mov bx, offset DOSBootSectorBuff ;mov cx, 1 call proc_disk_write mov ax, word ptr [BX]+492 mov dx, word ptr [BX]+494 retn retn_sffc_get_fsinfo_stc: ; 11/07/2010 xor bx, bx ; xor dx, dx mov ax, 0Bh ; Invalid format stc retn proc_set_first_free_cluster endp FAT_BuffDescriptor: FAT_CurrentCluster: dd 0 FAT_BuffValidData: db 0 FAT_BuffDrvName: db 0 FAT_BuffSector: dd 0 FAT_Buffer: dw 0 Dir_BuffDescriptor: DirBuff_DRV: db 0 DirBuff_FATType: db 0 DirBuff_ValidData: db 0 DirBuff_CurrentEntry: dw 0 DirBuff_LastEntry: dw 0 DirBuff_Cluster: dd 0 DirBuffer_Size: dw 0 Directory_Buffer: dw 0 DirBuff_EntryCounter: dw 0 ; 28/02/2010 FAT_ClusterCounter: dd 0 LastCluster: dd 0