;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; ;;
;; RAMDISK functions ;;
;; (C) 2004 Ville Turjanmaa, License: GPL ;;
;; Addings by M.Lisovin ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; calculate fat chain
calculatefatchain:
pushad
mov esi,0x100000+512
mov edi,0x280000
fcnew:
mov eax,dword [esi]
mov ebx,dword [esi+4]
mov ecx,dword [esi+8]
mov edx,ecx
shr edx,4 ;8 ok
shr dx,4 ;7 ok
xor ch,ch
shld ecx,ebx,20 ;6 ok
shr cx,4 ;5 ok
shld ebx,eax,12
and ebx,0x0fffffff ;4 ok
shr bx,4 ;3 ok
shl eax,4
and eax,0x0fffffff ;2 ok
shr ax,4 ;1 ok
mov dword [edi],eax
mov dword [edi+4],ebx
mov dword [edi+8],ecx
mov dword [edi+12],edx
add edi,16
add esi,12
cmp edi,0x280000+2856*2 ;2849 clusters
jnz fcnew
popad
ret
restorefatchain: ; restore fat chain
pushad
mov esi,0x280000
mov edi,0x100000+512
fcnew2:
mov eax,dword [esi]
mov ebx,dword [esi+4]
shl ax,4
shl eax,4
shl bx,4
shr ebx,4
shrd eax,ebx,8
shr ebx,8
mov dword [edi],eax
mov word [edi+4],bx
add edi,6
add esi,8
cmp edi,0x100000+512+4278 ;4274 bytes - all used FAT
jb fcnew2
mov esi,0x100000+512 ; duplicate fat chain
mov edi,0x100000+512+0x1200
mov ecx,1069 ;4274/4
cld
rep movsd
popad
ret
ramdisk_free_space:
;---------------------------------------------
;
; returns free space in edi
; rewr.by Mihasik
;---------------------------------------------
push eax ebx ecx
mov edi,0x280000 ;start of FAT
xor ax,ax ;Free cluster=0x0000 in FAT
xor ebx,ebx ;counter
mov ecx,2849 ;2849 clusters
cld
rdfs1:
repne scasw
jnz rdfs2 ;if last cluster not 0
inc ebx
test ecx, ecx
jnz rdfs1
rdfs2:
shl ebx,9 ;free clusters*512
mov edi,ebx
pop ecx ebx eax
ret
expand_filename:
;---------------------------------------------
;
; exapand filename with '.' to 11 character
; eax - pointer to filename
;---------------------------------------------
push esi edi ebx
mov edi,esp ; check for '.' in the name
add edi,12+8
mov esi,eax
mov eax,edi
mov [eax+0],dword ' '
mov [eax+4],dword ' '
mov [eax+8],dword ' '
flr1:
cmp [esi],byte '.'
jne flr2
mov edi,eax
add edi,7
jmp flr3
flr2:
mov bl,[esi]
mov [edi],bl
flr3:
inc esi
inc edi
mov ebx,eax
add ebx,11
cmp edi,ebx
jbe flr1
pop ebx edi esi
ret
fileread:
;----------------------------------------------------------------
;
; fileread - sys floppy
;
; eax points to filename 11 chars
; ebx first wanted block ; 1+ ; if 0 then set to 1
; ecx number of blocks to read ; 1+ ; if 0 then set to 1
; edx mem location to return data
; esi length of filename 12*X 0=root
;
; ret ebx = size or 0xffffffff file not found
; eax = 0 ok read or other = errormsg
;
;--------------------------------------------------------------
test ebx,ebx ;if ebx=0 - set to 1
jnz frfl5
inc ebx
frfl5:
test ecx,ecx ;if ecx=0 - set to 1
jnz frfl6
inc ecx
frfl6:
test esi,esi ; return ramdisk root
jnz fr_noroot ;if not root
cmp ebx,14 ;14 clusters=root dir
ja oorr
cmp ecx,14
ja oorr
jmp fr_do
oorr:
mov eax,5 ;out of root range (fnf)
xor ebx,ebx
dec ebx ;0xffffffff
ret
fr_do: ;reading rootdir
mov edi,edx
dec ebx
push edx
mov edx,ecx
add edx,ebx
cmp edx,15 ;ebx+ecx=14+1
pushf
jbe fr_do1
sub edx,14
sub ecx,edx
fr_do1:
shl ebx,9
mov esi,0x100000+512*19
add esi,ebx
shl ecx,7
cld
rep movsd
popf
pop edx
jae fr_do2
xor eax,eax ; ok read
xor ebx,ebx
ret
fr_do2: ;if last cluster
mov eax,6 ;end of file
xor ebx,ebx
ret
fr_noroot:
sub esp,32
call expand_filename
dec ebx
push eax
push eax ebx ecx edx esi edi
call rd_findfile
je fifound
add esp,32+28 ;if file not found
ret
fifound:
mov ebx,[edi-11+28] ;file size
mov [esp+20],ebx
mov [esp+24],ebx
add edi,0xf
movzx eax,word [edi]
mov edi,eax ;edi=cluster
frnew:
add eax,31 ;bootsector+2*fat+filenames
shl eax,9 ;*512
add eax,0x100000 ;image base
mov ebx,[esp+8]
mov ecx,512 ;[esp+4]
cmp [esp+16],dword 0 ; wanted cluster ?
jne frfl7
call memmove
add [esp+8],dword 512
dec dword [esp+12] ; last wanted cluster ?
je frnoread
jmp frfl8
frfl7:
dec dword [esp+16]
frfl8:
movzx eax,word [edi*2+0x280000] ; find next cluster from FAT
mov edi,eax
cmp edi,4095 ;eof - cluster
jz frnoread2
cmp [esp+24],dword 512 ;eof - size
jb frnoread
sub [esp+24],dword 512
jmp frnew
frnoread2:
cmp [esp+16],dword 0 ; eof without read ?
je frnoread
pop edi esi edx ecx
add esp,4
pop ebx ; ebx <- eax : size of file
add esp,36
mov eax,6 ; end of file
ret
frnoread:
pop edi esi edx ecx
add esp,4
pop ebx ; ebx <- eax : size of file
add esp,36
xor eax,eax ;read ok
ret
filedelete:
;--------------------------------------------
;
; filedelete - sys floppy
; in:
; eax - pointer to filename 11 chars
;
; out:
; eax - 0 = successful, 5 = file not found
;
;--------------------------------------------
sub esp,32
call expand_filename
push eax ebx ecx edx esi edi
call rd_findfile
je fifoundd
pop edi esi edx ecx ebx eax ;file not found
add esp,32
mov eax,5
ret
fifoundd:
mov [edi-11],byte 0xE5 ;mark filename deleted
add edi,0xf
movzx eax,word [edi]
mov edi,eax ;edi = cluster
frnewd:
shl edi,1 ;find next cluster from FAT
add edi,0x280000
movzx eax,word [edi]
mov [edi],word 0x0 ;clear fat chain cluster
mov edi,eax
cmp edi,dword 0xff8 ;last cluster ?
jb frnewd
pop edi esi edx ecx ebx eax
add esp,32
xor eax,eax ; file found
ret
filesave:
;----------------------------------------------------------
;
; filesave - sys floppy
;
; eax points to filename 11 chars
;
; eax ; pointer to file name
; ebx ; buffer
; ecx ; count to write in bytes
; edx ; 0 create new , 1 append
;
;-----------------------------------------------------------
sub esp,32
call expand_filename
test edx,edx
jnz fsdel
pusha
call filedelete
popa
fsdel:
call ramdisk_free_space
cmp ecx,edi
jbe rd_do_save
add esp,32
mov eax,8 ;disk full
ret
rd_do_save:
push eax ebx ecx edx esi edi
mov edi,0x100000+512*18+512 ;Point at directory
mov edx,224 +1
; find an empty spot for filename in the root dir
l20ds:
dec edx
test edx,edx
jz frnoreadds
l21ds:
cmp [edi],byte 0xE5
jz fifoundds
cmp [edi],byte 0x0
jz fifoundds
add edi,32 ; Advance to next entry
jmp l20ds
fifoundds:
push edi ; move the filename to root dir
mov esi,[esp+4+20]
mov ecx,11
cld
rep movsb
pop edi
mov edx,edi
add edx,11+0xf ; edx <- cluster save position
mov ebx,[esp+12] ; save file size
mov [edi+28],ebx
mov [edi+11],byte 0x20 ; attribute
; Ivan Poddubny 11/12/2003:
call get_date_for_file ; from FAT32.INC
mov [edi+24],ax ; date
call get_time_for_file ; from FAT32.INC
mov [edi+22],ax ; time
; End
mov edi,0x280000 ;pointer to first cluster
mov ecx,2849
cld
frnewds:
xor ax,ax
repne scasw
mov ebx,2848
sub ebx,ecx
mov [edx],bx ; save next cluster pos. to prev cl.
mov edx,edi ; next save pos abs mem add
dec edx
dec edx
call fdc_filesave
pusha ; move save to floppy cluster
add ebx,31
shl ebx,9
add ebx,0x100000
mov eax,[esp+32+16]
mov ecx,512
call memmove
popa
mov eax,[esp+12]
cmp eax,512
jbe flnsa
sub eax,512
mov [esp+12],eax
add dword [esp+16], 512
jmp frnewds
flnsa:
mov [edi-2],word 4095 ; mark end of file - last cluster
frnoreadds:
pop edi esi edx ecx ebx eax
add esp,32
; pusha
; cli
; call fdc_commitfile
; sti
; popa
xor eax,eax ;ok write
ret
rd_findfile:
;by Mihasik
;IN: eax - pointer to filename OUT: filestring+11 in edi or notZero in flags and fnf in eax,ebx
mov edi,0x100000+512*18+512 ;Point at directory
cld
rd_newsearch:
mov esi,eax
mov ecx,11
rep cmpsb
je rd_ff
add cl,21
add edi,ecx
cmp edi,0x100000+512*33
jb rd_newsearch
mov eax,5 ;if file not found - eax=5
xor ebx,ebx
dec ebx ;ebx=0xffffffff and zf=0
rd_ff:
ret
rd_getfileinfo:
;get date, time, size or attributes of file
;IN: eax - pointer to file, ebx - type of function: 12-get filesize, 13-get fileattr, 14-get filedate
;ecx - filelengh 0=root
;OUT: eax=0 - Ok or 5 - file not found ebx - date/time, size or attributes
test ecx,ecx
jnz no_getfinfo_root
mov eax,5 ;if root - fnf
xor ebx,ebx
dec ebx
ret
no_getfinfo_root: ;if not root
sub esp,32
call expand_filename
call rd_findfile
je fifoundi
add esp,32 ;if file not found
ret
fifoundi:
cmp ebx,13
jne no_rd_attr
movzx ebx,byte [edi] ;get attributes
jmp rd_getfileinfo_end
no_rd_attr:
cmp ebx,14
jne no_rd_date
mov ebx,dword [edi+11] ;get date/time
jmp rd_getfileinfo_end
no_rd_date:
mov ebx,dword [edi+17] ;get size
rd_getfileinfo_end:
xor eax,eax
add esp,32
ret
; \begin{diamond}
uni2ansi_str:
; convert UNICODE zero-terminated string to ASCII-string (codepage 866)
; in: esi->source, edi->buffer (may be esi=edi)
; destroys: eax,esi,edi
lodsw
test ax, ax
jz .done
cmp ax, 0x80
jb .ascii
cmp ax, 0x401
jz .yo1
cmp ax, 0x451
jz .yo2
cmp ax, 0x410
jb .unk
cmp ax, 0x440
jb .rus1
cmp ax, 0x450
jb .rus2
.unk:
mov al, '_'
jmp .doit
.yo1:
mov al, 'ð'
jmp .doit
.yo2:
mov al, 'ñ'
jmp .doit
.rus1:
; 0x410-0x43F -> 0x80-0xAF
add al, 0x70
jmp .doit
.rus2:
; 0x440-0x44F -> 0xE0-0xEF
add al, 0xA0
.ascii:
.doit:
stosb
jmp uni2ansi_str
.done:
mov byte [edi], 0
ret
ansi2uni_char:
; convert ANSI character in al to UNICODE character in ax, using cp866 encoding
mov ah, 0
; 0x00-0x7F - trivial map
cmp al, 0x80
jb .ret
; 0x80-0xAF -> 0x410-0x43F
cmp al, 0xB0
jae @f
add ax, 0x410-0x80
.ret:
ret
@@:
; 0xE0-0xEF -> 0x440-0x44F
cmp al, 0xE0
jb .unk
cmp al, 0xF0
jae @f
add ax, 0x440-0xE0
ret
; 0xF0 -> 0x401
; 0xF1 -> 0x451
@@:
cmp al, 'ð'
jz .yo1
cmp al, 'ñ'
jz .yo2
.unk:
mov al, '_' ; ah=0
ret
.yo1:
mov ax, 0x401
ret
.yo2:
mov ax, 0x451
ret
char_toupper:
; convert character to uppercase, using cp866 encoding
; in: al=symbol
; out: al=converted symbol
cmp al, 'a'
jb .ret
cmp al, 'z'
jbe .az
cmp al, ' '
jb .ret
cmp al, 'à'
jb .rus1
cmp al, 'ï'
ja .ret
; 0xE0-0xEF -> 0x90-0x9F
sub al, 'à'-''
.ret:
ret
.rus1:
; 0xA0-0xAF -> 0x80-0x8F
.az:
and al, not 0x20
ret
fat_get_name:
; in: edi->FAT entry
; out: CF=1 - no valid entry
; else CF=0 and ebp->ASCIIZ-name
; (maximum length of filename is 255 (wide) symbols without trailing 0,
; but implementation requires buffer 261 words)
; destroys eax
cmp byte [edi], 0
jz .no
cmp byte [edi], 0xE5
jnz @f
.no:
stc
ret
@@:
cmp byte [edi+11], 0xF
jz .longname
push ecx
mov ecx, 8
push edi ebp ecx
test byte [ebp-4], 1
jnz .unicode_short
@@:
mov al, [edi]
inc edi
mov [ebp], al
inc ebp
loop @b
pop ecx
@@:
cmp byte [ebp-1], ' '
jnz @f
dec ebp
loop @b
@@:
mov byte [ebp], '.'
inc ebp
mov ecx, 3
push ecx
@@:
mov al, [edi]
inc edi
mov [ebp], al
inc ebp
loop @b
pop ecx
@@:
cmp byte [ebp-1], ' '
jnz @f
dec ebp
loop @b
dec ebp
@@:
and byte [ebp], 0 ; CF=0
pop ebp edi ecx
ret
.unicode_short:
@@:
mov al, [edi]
inc edi
call ansi2uni_char
mov [ebp], ax
inc ebp
inc ebp
loop @b
pop ecx
@@:
cmp word [ebp-2], ' '
jnz @f
dec ebp
dec ebp
loop @b
@@:
mov word [ebp], '.'
inc ebp
inc ebp
mov ecx, 3
push ecx
@@:
mov al, [edi]
inc edi
call ansi2uni_char
mov [ebp], ax
inc ebp
inc ebp
loop @b
pop ecx
@@:
cmp word [ebp-2], ' '
jnz @f
dec ebp
dec ebp
loop @b
dec ebp
dec ebp
@@:
and word [ebp], 0 ; CF=0
pop ebp edi ecx
ret
.longname:
; LFN
mov al, byte [edi]
and eax, 0x3F
dec eax
cmp al, 20
jae .no ; ignore invalid entries
mov word [ebp+260*2], 0 ; force null-terminating for orphans
imul eax, 13*2
add ebp, eax
test byte [edi], 0x40
jz @f
mov word [ebp+13*2], 0
@@:
push eax
; now copy name from edi to ebp ...
mov eax, [edi+1]
mov [ebp], eax ; symbols 1,2
mov eax, [edi+5]
mov [ebp+4], eax ; 3,4
mov eax, [edi+9]
mov [ebp+8], ax ; 5
mov eax, [edi+14]
mov [ebp+10], eax ; 6,7
mov eax, [edi+18]
mov [ebp+14], eax ; 8,9
mov eax, [edi+22]
mov [ebp+18], eax ; 10,11
mov eax, [edi+28]
mov [ebp+22], eax ; 12,13
; ... done
pop eax
sub ebp, eax
test eax, eax
jz @f
; if this is not first entry, more processing required
stc
ret
@@:
; if this is first entry:
test byte [ebp-4], 1
jnz .ret
; buffer at ebp contains UNICODE name, convert it to ANSI
push esi edi
mov esi, ebp
mov edi, ebp
call uni2ansi_str
pop edi esi
.ret:
clc
ret
fat_compare_name:
; compares ASCIIZ-names, case-insensitive (cp866 encoding)
; in: esi->name, ebp->name
; out: if names match: ZF=1 and esi->next component of name
; else: ZF=0, esi is not changed
; destroys eax
push ebp esi
.loop:
mov al, [ebp]
inc ebp
call char_toupper
push eax
lodsb
call char_toupper
cmp al, [esp]
jnz .done
pop eax
test al, al
jnz .loop
dec esi
pop eax
pop ebp
xor eax, eax ; set ZF flag
ret
.done:
cmp al, '/'
jnz @f
cmp byte [esp], 0
jnz @f
mov [esp+4], esi
@@:
pop eax
pop esi ebp
ret
fat_time_to_bdfe:
; in: eax=FAT time
; out: eax=BDFE time
push ecx edx
mov ecx, eax
mov edx, eax
shr eax, 11
shl eax, 16 ; hours
and edx, 0x1F
add edx, edx
mov al, dl ; seconds
shr ecx, 5
and ecx, 0x3F
mov ah, cl ; minutes
pop edx ecx
ret
fat_date_to_bdfe:
push ecx edx
mov ecx, eax
mov edx, eax
shr eax, 9
add ax, 1980
shl eax, 16 ; year
and edx, 0x1F
mov al, dl ; day
shr ecx, 5
and ecx, 0xF
mov ah, cl ; month
pop edx ecx
ret
fat_entry_to_bdfe:
; convert FAT entry at edi to BDFE (block of data of folder entry) at esi, advance esi
; destroys eax
movzx eax, byte [edi+11]
mov [esi], eax ; attributes
mov eax, [ebp-4]
mov [esi+4], eax ; ASCII/UNICODE name
movzx eax, word [edi+14]
call fat_time_to_bdfe
mov [esi+8], eax ; creation time
movzx eax, word [edi+16]
call fat_date_to_bdfe
mov [esi+12], eax ; creation date
and dword [esi+16], 0 ; last access time is not supported on FAT
movzx eax, word [edi+18]
call fat_date_to_bdfe
mov [esi+20], eax ; last access date
movzx eax, word [edi+22]
call fat_time_to_bdfe
mov [esi+24], eax ; last write time
movzx eax, word [edi+24]
call fat_date_to_bdfe
mov [esi+28], eax ; last write date
mov eax, [edi+28]
mov [esi+32], eax ; file size (low dword)
xor eax, eax
mov [esi+36], eax ; file size (high dword)
push ecx edi
lea edi, [esi+40]
mov esi, ebp
test byte [esi-4], 1
jz .ansi
mov ecx, 260/2
rep movsd
mov [edi-2], ax
@@:
mov esi, edi
pop edi ecx
ret
.ansi:
mov ecx, 264/4
rep movsd
mov [edi-1], al
jmp @b
rd_find_lfn:
; in: esi->name
; out: CF=1 - file not found
; else CF=0 and edi->direntry
push esi ebp edi
sub esp, 262*2 ; allocate space for LFN
mov ebp, esp ; ebp points to buffer
push 0 ; for fat_get_name: read ASCII name
mov edi, 0x100000+512*19 ; to root dir
.l1:
call fat_get_name
jc .l2
call fat_compare_name
jz .found
.l2:
add edi, 0x20
cmp edi, 0x100000+512*33
jb .l1
.notfound:
add esp, 262*2+4
pop edi ebp esi
stc
ret
.found:
; found
; if this is LFN entry, advance to true entry
cmp byte [edi+11], 0xF
jnz @f
add edi, 0x20
@@:
; folders are not supported
cmp byte [esi], 0
jnz .notfound
add esp, 262*2+4+4 ; CF=0
pop ebp esi
ret
;----------------------------------------------------------------
;
; fs_RamdiskRead - LFN variant for reading sys floppy
;
; esi points to filename
; ebx pointer to 64-bit number = first wanted byte, 0+
; may be ebx=0 - start from first byte
; ecx number of bytes to read, 0+
; edx mem location to return data
;
; ret ebx = bytes read or 0xffffffff file not found
; eax = 0 ok read or other = errormsg
;
;--------------------------------------------------------------
fs_RamdiskRead:
cmp byte [esi], 0
jnz @f
or ebx, -1
mov eax, 10 ; access denied
ret
@@:
push edi
call rd_find_lfn
jnc .found
pop edi
or ebx, -1
mov eax, 5 ; file not found
ret
.found:
test ebx, ebx
jz .l1
cmp dword [ebx+4], 0
jz @f
xor ebx, ebx
.reteof:
mov eax, 6 ; EOF
pop edi
ret
@@:
mov ebx, [ebx]
.l1:
push ecx edx
push 0
mov eax, [edi+28]
sub eax, ebx
jb .eof
cmp eax, ecx
jae @f
mov ecx, eax
mov byte [esp], 6 ; EOF
@@:
movzx edi, word [edi+26] ; cluster
.new:
jecxz .done
test edi, edi
jz .eof
cmp edi, 0xFF8
jae .eof
lea eax, [edi+31] ; bootsector+2*fat+filenames
shl eax, 9 ; *512
add eax, 0x100000 ; image base
; now eax points to data of cluster
sub ebx, 512
jae .skip
lea eax, [eax+ebx+512]
neg ebx
push ecx
cmp ecx, ebx
jbe @f
mov ecx, ebx
@@:
mov ebx, edx
call memmove
add edx, ecx
sub [esp], ecx
pop ecx
xor ebx, ebx
.skip:
movzx edi, word [edi*2+0x280000] ; find next cluster from FAT
jmp .new
.eof:
mov ebx, edx
pop eax edx ecx
sub ebx, edx
jmp .reteof
.done:
mov ebx, edx
pop eax edx ecx edi
sub ebx, edx
ret
;----------------------------------------------------------------
;
; fs_RamdiskReadFolder - LFN variant for reading sys floppy folder
;
; esi points to filename; only root is folder on ramdisk
; ebx pointer to structure 32-bit number = first wanted block
; & flags (bitfields)
; flags: bit 0: 0=ANSI names, 1=UNICODE names
; ecx number of blocks to read, 0+
; edx mem location to return data
;
; ret ebx = size or 0xffffffff file not found
; eax = 0 ok read or other = errormsg
;
;--------------------------------------------------------------
fs_RamdiskReadFolder:
cmp byte [esi], 0
jz @f
; ramdisk doesn't support folders
mov eax, ERROR_ACCESS_DENIED
or ebx, -1
ret
@@:
push esi edi ecx
; init header
push ecx
mov edi, edx
mov ecx, 32/4
xor eax, eax
rep stosd
mov byte [edx], 1 ; version
pop ecx
push ebp
sub esp, 262*2 ; allocate space for LFN
mov ebp, esp
push dword [ebx+4] ; for fat_get_name: read ANSI/UNICODE name
mov ebx, [ebx]
; read root
mov esi, edi ; esi points to block of data of folder entry (BDFE)
mov edi, 0x100000+512*19
.l1:
call fat_get_name
jc .l2
cmp byte [edi+11], 0xF
jnz @f
add edi, 0x20
@@:
inc dword [edx+8] ; new file found
dec ebx
jns .l2
dec ecx
js .l2
inc dword [edx+4] ; new file block copied
call fat_entry_to_bdfe
.l2:
add edi, 0x20
cmp edi, 0x100000+512*33
jb .l1
add esp, 262*2+4
pop ebp
mov ebx, [edx+4]
xor eax, eax
dec ecx
js @f
mov al, ERROR_END_OF_FILE
@@:
pop ecx edi esi
ret
; \end{diamond}