;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; ;;
;; 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
add edi,4
mov dword [edi],ebx
add edi,4
mov dword [edi],ecx
add edi,4
mov dword [edi],edx
add edi,4
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
add edi,4
mov word [edi],bx
add edi,2
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
jcxz rdfs2 ;if last cluster=0
jmp rdfs1 ;if not last
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 ?
cmp [esp+12],dword 0
je frnoread
jmp frfl8
frfl7:
dec dword [esp+16]
frfl8:
shl edi,1 ;find next cluster from FAT
add edi,0x280000
movzx eax,word [edi]
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
mov eax,[esp+16]
add eax,512
mov [esp+16],eax
jmp frnewds
flnsa:
dec edi
dec edi
mov [edi],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