forked from KolibriOS/kolibrios
Now correctly loads FAT12 from floppies of any volume into ramdisk, rather than only from 1.44 MB
git-svn-id: svn://kolibrios.org@795 a494cfbc-eb01-0410-851d-a64ba20cac60
This commit is contained in:
Dmitry Kartashov (shurf)
parent
16b20de954
commit
8ca0210b13
@ -99,6 +99,45 @@ sayerr_plain:
|
||||
pop si
|
||||
ret
|
||||
|
||||
; convert abs. sector number (AX) to BIOS T:H:S
|
||||
; sector number = (abs.sector%BPB_SecPerTrk)+1
|
||||
; pre.track number = (abs.sector/BPB_SecPerTrk)
|
||||
; head number = pre.track number%BPB_NumHeads
|
||||
; track number = pre.track number/BPB_NumHeads
|
||||
; Return: cl - sector number
|
||||
; ch - track number
|
||||
; dl - drive number (0 = a:)
|
||||
; dh - head number
|
||||
conv_abs_to_THS:
|
||||
push bx
|
||||
mov bx,word [BPB_SecPerTrk]
|
||||
xor dx,dx
|
||||
div bx
|
||||
inc dx
|
||||
mov cl, dl ; cl = sector number
|
||||
mov bx,word [BPB_NumHeads]
|
||||
xor dx,dx
|
||||
div bx
|
||||
; !!!!!!! ax = track number, dx = head number
|
||||
mov ch,al ; ch=track number
|
||||
xchg dh,dl ; dh=head number
|
||||
mov dl,0 ; dl=0 (drive 0 (a:))
|
||||
pop bx
|
||||
retn
|
||||
; needed variables
|
||||
BPB_SecPerTrk dw 0 ; sectors per track
|
||||
BPB_NumHeads dw 0 ; number of heads
|
||||
BPB_FATSz16 dw 0 ; size of FAT
|
||||
BPB_RootEntCnt dw 0 ; count of root dir. entries
|
||||
BPB_BytsPerSec dw 0 ; bytes per sector
|
||||
BPB_RsvdSecCnt dw 0 ; number of reserved sectors
|
||||
BPB_TotSec16 dw 0 ; count of the sectors on the volume
|
||||
BPB_SecPerClus db 0 ; number of sectors per cluster
|
||||
BPB_NumFATs db 0 ; number of FAT tables
|
||||
abs_sector_adj dw 0 ; adjustment to make abs. sector number
|
||||
end_of_FAT dw 0 ; end of FAT table
|
||||
FirstDataSector dw 0 ; begin of data
|
||||
|
||||
;=========================================================================
|
||||
;
|
||||
; 16 BIT CODE
|
||||
@ -803,6 +842,11 @@ end if
|
||||
pop ds
|
||||
jz .nocd
|
||||
; yes - read all floppy by 18 sectors
|
||||
|
||||
; TODO: !!!! read only first sector and set variables !!!!!
|
||||
; ...
|
||||
; TODO: !!! then read flippy image track by track
|
||||
|
||||
mov cx, 0x0001 ; startcyl,startsector
|
||||
.a1:
|
||||
push cx dx
|
||||
@ -844,20 +888,68 @@ end if
|
||||
; no - read only used sectors from floppy
|
||||
; now load floppy image to memory
|
||||
; at first load boot sector and first FAT table
|
||||
mov cx, 0x0001 ; startcyl,startsector
|
||||
xor dx, dx ; starthead,drive
|
||||
mov al, 1+9 ; no of sectors to read
|
||||
|
||||
; read only first sector and fill variables
|
||||
mov cx, 0x0001 ; first logical sector
|
||||
xor dx, dx ; head = 0, drive = 0 (a:)
|
||||
mov al, 1 ; read one sector
|
||||
mov bx, 0xB000 ; es:bx -> data area
|
||||
call boot_read_floppy
|
||||
; fill the necessary parameters to work with a floppy
|
||||
mov ax, word [es:bx+24]
|
||||
mov word [BPB_SecPerTrk], ax
|
||||
mov ax, word [es:bx+26]
|
||||
mov word [BPB_NumHeads], ax
|
||||
mov ax, word [es:bx+22]
|
||||
mov word [BPB_FATSz16], ax
|
||||
mov ax, word [es:bx+17]
|
||||
mov word [BPB_RootEntCnt], ax
|
||||
mov ax, word [es:bx+11]
|
||||
mov word [BPB_BytsPerSec], ax
|
||||
mov ax, word [es:bx+14]
|
||||
mov word [BPB_RsvdSecCnt], ax
|
||||
mov ax, word [es:bx+19]
|
||||
mov word [BPB_TotSec16], ax
|
||||
mov al, byte [es:bx+13]
|
||||
mov byte [BPB_SecPerClus], al
|
||||
mov al, byte [es:bx+16]
|
||||
mov byte [BPB_NumFATs], al
|
||||
; count of clusters in FAT12 ((size_of_FAT*2)/3)
|
||||
mov ax, word [BPB_FATSz16]
|
||||
mov cx, word [BPB_BytsPerSec]
|
||||
xor dx, dx
|
||||
mul cx
|
||||
shl ax, 1
|
||||
mov cx, 3
|
||||
div cx ; now ax - number of clusters in FAT12
|
||||
mov word [end_of_FAT], ax
|
||||
|
||||
; load first FAT table
|
||||
mov cx, 0x0002 ; startcyl,startsector ; TODO!!!!!
|
||||
xor dx, dx ; starthead,drive
|
||||
mov al, byte [BPB_FATSz16] ; no of sectors to read
|
||||
add bx, word [BPB_BytsPerSec] ; es:bx -> data area
|
||||
call boot_read_floppy
|
||||
mov bx, 0xB000
|
||||
|
||||
; and copy them to extended memory
|
||||
mov si, movedesc
|
||||
mov [si+8*2+3], bh
|
||||
mov [si+8*2+3], bh ; from
|
||||
|
||||
mov ax, word [BPB_BytsPerSec]
|
||||
shr ax, 1 ; words per sector
|
||||
mov cx, word [BPB_RsvdSecCnt]
|
||||
add cx, word [BPB_FATSz16]
|
||||
mul cx
|
||||
push ax ; save to stack count of words in boot+FAT
|
||||
xchg ax, cx
|
||||
|
||||
push es
|
||||
push ds
|
||||
pop es
|
||||
mov cx, 256*10
|
||||
mov ah, 0x87
|
||||
int 0x15
|
||||
pop es
|
||||
test ah, ah
|
||||
jz @f
|
||||
sayerr_floppy:
|
||||
@ -867,89 +959,153 @@ sayerr_floppy:
|
||||
mov si, memmovefailed
|
||||
jmp sayerr_plain
|
||||
@@:
|
||||
add dword [si+8*3+2], 512*10
|
||||
; copy FAT to second copy
|
||||
mov byte [si+8*2+3], 0xB2
|
||||
mov cx, 256*9
|
||||
pop ax ; restore from stack count of words in boot+FAT
|
||||
shl ax, 1 ; make bytes count from count of words
|
||||
and eax, 0ffffh
|
||||
add dword [si+8*3+2], eax
|
||||
|
||||
; copy first FAT to second copy
|
||||
; TODO: BPB_NumFATs !!!!!
|
||||
add bx, word [BPB_BytsPerSec] ; !!! TODO: may be need multiply by BPB_RsvdSecCnt !!!
|
||||
mov byte [si+8*2+3], bh ; bx - begin of FAT
|
||||
|
||||
mov ax, word [BPB_BytsPerSec]
|
||||
shr ax, 1 ; words per sector
|
||||
mov cx, word [BPB_FATSz16]
|
||||
mul cx
|
||||
mov cx, ax ; cx - count of words in FAT
|
||||
|
||||
push es
|
||||
push ds
|
||||
pop es
|
||||
mov ah, 0x87
|
||||
int 0x15
|
||||
pop es
|
||||
test ah, ah
|
||||
jnz sayerr_floppy
|
||||
add dword [si+8*3+2], 512*9
|
||||
; calculate total number of sectors to read
|
||||
mov ax, 1+9+14 ; boot+FAT+root
|
||||
mov di, 0xB203
|
||||
.calc_loop:
|
||||
test word [es:di], 0xFFF
|
||||
jz @f
|
||||
inc ax
|
||||
@@:
|
||||
test word [es:di+1], 0xFFF0
|
||||
jz @f
|
||||
inc ax
|
||||
@@:
|
||||
add di, 3
|
||||
cmp di, 0xB200+1440*3
|
||||
jb .calc_loop
|
||||
|
||||
mov ax, cx
|
||||
shl ax, 1
|
||||
and eax, 0ffffh ; ax - count of bytes in FAT
|
||||
add dword [si+8*3+2], eax
|
||||
|
||||
; reading RootDir
|
||||
; TODO: BPB_NumFATs
|
||||
add bx, ax
|
||||
add bx, 100h
|
||||
and bx, 0ff00h ; bx - place in buffer to write RootDir
|
||||
push bx
|
||||
|
||||
mov bx, word [BPB_BytsPerSec]
|
||||
shr bx, 5 ; divide bx by 32
|
||||
mov ax, word [BPB_RootEntCnt]
|
||||
xor dx, dx
|
||||
div bx
|
||||
push ax ; ax - count of RootDir sectors
|
||||
|
||||
mov ax, word [BPB_FATSz16]
|
||||
xor cx, cx
|
||||
mov cl, byte [BPB_NumFATs]
|
||||
mul cx
|
||||
add ax, word [BPB_RsvdSecCnt] ; ax - first sector of RootDir
|
||||
|
||||
mov word [FirstDataSector], ax
|
||||
pop bx
|
||||
push bx
|
||||
add word [FirstDataSector], bx ; Begin of data region of floppy
|
||||
|
||||
; read RootDir
|
||||
call conv_abs_to_THS
|
||||
pop ax
|
||||
pop bx ; place in buffer to write
|
||||
push ax
|
||||
mov bp, 1+9 ; already read sectors
|
||||
; now read rest
|
||||
mov byte [si+8*2+3], 0xA0
|
||||
mov di, 2-14 ; absolute sector-31
|
||||
mov cx, 0x0002 ; cylinder=0, sector=2
|
||||
mov dx, 0x0100 ; head=1, disk=0
|
||||
call boot_read_floppy ; read RootDir into buffer
|
||||
; copy RootDir
|
||||
mov byte [si+8*2+3], bh ; from buffer
|
||||
pop ax ; ax = count of RootDir sectors
|
||||
mov cx, word [BPB_BytsPerSec]
|
||||
mul cx
|
||||
shr ax, 1
|
||||
mov cx, ax ; count of words to copy
|
||||
push es
|
||||
push ds
|
||||
pop es
|
||||
mov ah, 0x87
|
||||
int 0x15
|
||||
pop es
|
||||
|
||||
mov ax, cx
|
||||
shl ax, 1
|
||||
and eax, 0ffffh ; ax - count of bytes in RootDir
|
||||
add dword [si+8*3+2], eax ; add count of bytes copied
|
||||
|
||||
; Reading data clusters from floppy
|
||||
mov byte [si+8*2+3], bh
|
||||
push bx
|
||||
|
||||
mov di, 2 ; First data cluster
|
||||
.read_loop:
|
||||
; determine whether sector must be read
|
||||
cmp di, 2
|
||||
jl .read
|
||||
mov bx, di
|
||||
shr bx, 1
|
||||
shr bx, 1 ; bx+di = di*1.5
|
||||
jnc .even
|
||||
test word [es:bx+di+0xB200], 0xFFF0
|
||||
test word [es:bx+di+0xB200], 0xFFF0 ; TODO: may not be 0xB200 !!!
|
||||
jmp @f
|
||||
.even:
|
||||
test word [es:bx+di+0xB200], 0xFFF
|
||||
test word [es:bx+di+0xB200], 0xFFF ; TODO: may not be 0xB200 !!!
|
||||
|
||||
@@:
|
||||
jz .skip
|
||||
.read:
|
||||
mov bx, 0xA000
|
||||
mov al, 1 ; 1 sector
|
||||
; read cluster di
|
||||
;.read:
|
||||
;conv cluster di to abs. sector ax
|
||||
; ax = (N-2) * BPB_SecPerClus + FirstDataSector
|
||||
mov ax, di
|
||||
sub ax, 2
|
||||
xor bx, bx
|
||||
mov bl, byte [BPB_SecPerClus]
|
||||
mul bx
|
||||
add ax, word [FirstDataSector]
|
||||
call conv_abs_to_THS
|
||||
pop bx
|
||||
push bx
|
||||
mov al, byte [BPB_SecPerClus] ; number of sectors in cluster
|
||||
call boot_read_floppy
|
||||
inc bp
|
||||
push es
|
||||
push ds
|
||||
pop es
|
||||
pusha
|
||||
mov cx, 256
|
||||
;
|
||||
mov ax, word [BPB_BytsPerSec]
|
||||
xor cx, cx
|
||||
mov cl, byte [BPB_SecPerClus]
|
||||
mul cx
|
||||
shr ax, 1 ; ax = (BPB_BytsPerSec * BPB_SecPerClus)/2
|
||||
mov cx, ax ; number of words to copy (count words in cluster)
|
||||
;
|
||||
mov ah, 0x87
|
||||
int 0x15
|
||||
int 0x15 ; copy data
|
||||
test ah, ah
|
||||
popa
|
||||
pop es
|
||||
jnz sayerr_floppy
|
||||
; skip cluster di
|
||||
.skip:
|
||||
add dword [si+8*3+2], 512
|
||||
inc cx
|
||||
cmp cl, 19
|
||||
jnz @f
|
||||
mov cl, 1
|
||||
inc dh
|
||||
cmp dh, 2
|
||||
jnz @f
|
||||
mov dh, 0
|
||||
inc ch
|
||||
@@:
|
||||
pop ax
|
||||
push ax
|
||||
mov ax, word [BPB_BytsPerSec]
|
||||
xor cx, cx
|
||||
mov cl, byte [BPB_SecPerClus]
|
||||
mul cx
|
||||
and eax, 0ffffh ; ax - count of bytes in cluster
|
||||
add dword [si+8*3+2], eax
|
||||
|
||||
mov ax, word [end_of_FAT] ; max cluster number
|
||||
pusha
|
||||
; draw percentage
|
||||
; total sectors: ax
|
||||
; read sectors: bp
|
||||
xchg ax, bp
|
||||
; total clusters: ax
|
||||
; read clusters: di
|
||||
xchg ax, di
|
||||
mov cx, 100
|
||||
mul cx
|
||||
div bp
|
||||
div di
|
||||
aam
|
||||
xchg al, ah
|
||||
add ax, '00'
|
||||
@ -961,76 +1117,9 @@ sayerr_floppy:
|
||||
@@:
|
||||
popa
|
||||
inc di
|
||||
cmp di, 2880-31
|
||||
cmp di, word [end_of_FAT] ; max number of cluster
|
||||
jnz .read_loop
|
||||
|
||||
; mov cx, 0x0001 ; startcyl,startsector
|
||||
; xor dx, dx ; starthead,drive
|
||||
; push word 80*2 ; read no of sect
|
||||
; reads:
|
||||
; pusha
|
||||
; xor si,si
|
||||
; newread:
|
||||
; mov bx,0xa000 ; es:bx -> data area
|
||||
; mov ax,0x0200+18 ; read, no of sectors to read
|
||||
; int 0x13
|
||||
; test ah, ah
|
||||
; jz goodread
|
||||
; inc si
|
||||
; cmp si,10
|
||||
; jnz newread
|
||||
; mov si,badsect-0x10000
|
||||
;sayerr_plain:
|
||||
; call printplain
|
||||
; jmp $
|
||||
; goodread:
|
||||
; ; move -> 1mb
|
||||
; mov si,movedesc-0x10000
|
||||
; push es
|
||||
; push ds
|
||||
; pop es
|
||||
; mov cx,256*18
|
||||
; mov ah,0x87
|
||||
; int 0x15
|
||||
; pop es
|
||||
;
|
||||
; test ah,ah ; was the move successfull ?
|
||||
; je goodmove
|
||||
; mov dx,0x3f2 ; floppy motor off
|
||||
; mov al,0
|
||||
; out dx,al
|
||||
; mov si,memmovefailed-0x10000
|
||||
; jmp sayerr_plain
|
||||
; goodmove:
|
||||
;
|
||||
; add dword [movedesc-0x10000+0x18+2], 512*18
|
||||
; popa
|
||||
; inc dh
|
||||
; cmp dh,2
|
||||
; jnz bb2
|
||||
; mov dh,0
|
||||
; inc ch
|
||||
; pusha ; print prosentage
|
||||
; mov si,pros-0x10000
|
||||
; shr ch, 2
|
||||
; mov al, '5'
|
||||
; test ch, 1
|
||||
; jnz @f
|
||||
; mov al, '0'
|
||||
;@@:
|
||||
; mov [si+1], al
|
||||
; shr ch, 1
|
||||
; add ch, '0'
|
||||
; mov [si], ch
|
||||
; call printplain
|
||||
; popa
|
||||
; bb2:
|
||||
; pop ax
|
||||
; dec ax
|
||||
; push ax
|
||||
; jnz reads
|
||||
; readdone:
|
||||
; pop ax
|
||||
pop bx ; clear stack
|
||||
|
||||
ok_sys_on_floppy:
|
||||
mov si, backspace2
|
||||
|
||||
Loading…
Reference in New Issue
Block a user