;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; ;; ;; RAMDISK functions ;; ;; (C) 2004 Ville Turjanmaa, License: GPL ;; ;; Addings by M.Lisovin ;; ;; LFN support by diamond ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; 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 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 ; \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, '' jmp .doit .yo2: mov al, '' 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, '' jz .yo1 cmp al, '' 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, '' jb .rus1 cmp al, '' ja .ret ; 0xE0-0xEF -> 0x90-0x9F sub al, ''-'' .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 push edi ebp test byte [ebp-4], 1 jnz .unicode_short mov eax, [edi] mov ecx, [edi+4] mov [ebp], eax mov [ebp+4], ecx mov ecx, 8 @@: cmp byte [ebp+ecx-1], ' ' loope @b mov eax, [edi+8] cmp al, ' ' je .done shl eax, 8 mov al, '.' lea ebp, [ebp+ecx+1] mov [ebp], eax mov ecx, 3 @@: rol eax, 8 cmp al, ' ' jne .done loop @b dec ebp .done: and byte [ebp+ecx+1], 0 ; CF=0 pop ebp edi ecx ret .unicode_short: mov ecx, 8 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 @@: 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 bdfe_to_fat_time: push edx mov edx, eax shr eax, 16 and dh, 0x3F shl eax, 6 or al, dh shr dl, 1 and dl, 0x1F shl eax, 5 or al, dl pop edx ret bdfe_to_fat_date: push edx mov edx, eax shr eax, 16 sub ax, 1980 and dh, 0xF shl eax, 4 or al, dh and dl, 0x1F shl eax, 5 or al, dl pop edx ret fat_entry_to_bdfe: ; convert FAT entry at edi to BDFE (block of data of folder entry) at esi, advance esi ; destroys eax mov eax, [ebp-4] mov [esi+4], eax ; ASCII/UNICODE name fat_entry_to_bdfe2: movzx eax, byte [edi+11] mov [esi], eax ; attributes 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) test ebp, ebp jz .ret 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: ret .ansi: mov ecx, 264/4 rep movsd mov [edi-1], al jmp @b bdfe_to_fat_entry: ; convert BDFE at edx to FAT entry at edi ; destroys eax ; attributes byte test byte [edi+11], 8 ; volume label? jnz @f mov al, [edx] and al, 0x27 and byte [edi+11], 0x10 or byte [edi+11], al @@: mov eax, [edx+8] call bdfe_to_fat_time mov [edi+14], ax ; creation time mov eax, [edx+12] call bdfe_to_fat_date mov [edi+16], ax ; creation date mov eax, [edx+20] call bdfe_to_fat_date mov [edi+18], ax ; last access date mov eax, [edx+24] call bdfe_to_fat_time mov [edi+22], ax ; last write time mov eax, [edx+28] call bdfe_to_fat_date mov [edi+24], ax ; last write date ret ramdisk_root_first: mov edi, 0x100000+512*19 clc ret ramdisk_root_next: add edi, 0x20 cmp edi, 0x100000+512*33 cmc ret ramdisk_root_extend_dir: stc ret uglobal ; this is for delete support rd_prev_sector dd ? rd_prev_prev_sector dd ? endg ramdisk_notroot_next: add edi, 0x20 test edi, 0x1FF jz ramdisk_notroot_next_sector ret ; CF=0 ramdisk_notroot_next_sector: push ecx mov ecx, [eax] push [rd_prev_sector] pop [rd_prev_prev_sector] mov [rd_prev_sector], ecx mov ecx, [ecx*2+0x280000] and ecx, 0xFFF cmp ecx, 2849 jae ramdisk_notroot_first.err2 mov [eax], ecx pop ecx ramdisk_notroot_first: mov eax, [eax] cmp eax, 2 jb .err cmp eax, 2849 jae .err shl eax, 9 lea edi, [eax+(31 shl 9)+0x100000] clc ret .err2: pop ecx .err: stc ret ramdisk_notroot_next_write: test edi, 0x1FF jz ramdisk_notroot_next_sector ramdisk_root_next_write: ret ramdisk_notroot_extend_dir: pusha xor eax, eax mov edi, 0x280000 mov ecx, 2849 repnz scasw jnz .notfound mov word [edi-2], 0xFFF sub edi, 0x280000 shr edi, 1 dec edi mov eax, [esp+28] mov ecx, [eax] mov [0x280000+ecx*2], di mov [eax], edi shl edi, 9 add edi, (31 shl 9)+0x100000 mov [esp], edi xor eax, eax mov ecx, 128 rep stosd popa clc ret .notfound: popa stc ret rd_find_lfn: ; in: esi->name ; out: CF=1 - file not found ; else CF=0 and edi->direntry push esi edi push 0 push ramdisk_root_first push ramdisk_root_next .loop: call fat_find_lfn jc .notfound cmp byte [esi], 0 jz .found test byte [edi+11], 10h jz .notfound movzx eax, word [edi+26] mov [esp+8], eax mov dword [esp+4], ramdisk_notroot_first mov dword [esp], ramdisk_notroot_next jmp .loop .notfound: add esp, 12 pop edi esi stc ret .found: mov eax, [esp+8] add esp, 16 ; CF=0 pop 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: push edi cmp byte [esi], 0 jz .root call rd_find_lfn jnc .found pop edi or ebx, -1 mov eax, ERROR_FILE_NOT_FOUND ret .found: test byte [edi+11], 0x10 jnz .found_dir pop edi or ebx, -1 mov eax, ERROR_ACCESS_DENIED ret .found_dir: movzx eax, word [edi+26] add eax, 31 push 0 jmp .doit .root: mov eax, 19 push 14 .doit: push esi ecx ebp sub esp, 262*2 ; reserve space for LFN mov ebp, esp push dword [ebx+4] ; for fat_get_name: read ANSI/UNICODE names mov ebx, [ebx] ; init header push eax ecx mov edi, edx mov ecx, 32/4 xor eax, eax rep stosd mov byte [edx], 1 ; version pop ecx eax mov esi, edi ; esi points to block of data of folder entry (BDFE) .main_loop: mov edi, eax shl edi, 9 add edi, 0x100000 push eax .l1: call fat_get_name jc .l2 cmp byte [edi+11], 0xF jnz .do_bdfe add edi, 0x20 test edi, 0x1FF jnz .do_bdfe pop eax inc eax dec byte [esp+262*2+16] jz .done jns @f ; read next sector from FAT mov eax, [(eax-31-1)*2+0x280000] and eax, 0xFFF cmp eax, 0xFF8 jae .done add eax, 31 mov byte [esp+262*2+16], 0 @@: mov edi, eax shl edi, 9 add edi, 0x100000 push eax .do_bdfe: 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 test edi, 0x1FF jnz .l1 pop eax inc eax dec byte [esp+262*2+16] jz .done jns @f ; read next sector from FAT mov eax, [(eax-31-1)*2+0x280000] and eax, 0xFFF cmp eax, 0xFF8 jae .done add eax, 31 mov byte [esp+262*2+16], 0 @@: jmp .main_loop .done: 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 esi edi edi ret iglobal label fat_legal_chars byte ; 0 = not allowed ; 1 = allowed only in long names ; 3 = allowed times 32 db 0 ; ! " # $ % & ' ( ) * + , - . / db 1,3,0,3,3,3,3,3,3,3,0,1,1,3,3,0 ; 0 1 2 3 4 5 6 7 8 9 : ; < = > ? db 3,3,3,3,3,3,3,3,3,3,0,1,0,1,0,0 ; @ A B C D E F G H I J K L M N O db 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3 ; P Q R S T U V W X Y Z [ \ ] ^ _ db 3,3,3,3,3,3,3,3,3,3,3,1,0,1,3,3 ; ` a b c d e f g h i j k l m n o db 3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3 ; p q r s t u v w x y z { | } ~ db 3,3,3,3,3,3,3,3,3,3,3,3,0,3,3,0 endg fat_name_is_legal: ; in: esi->(long) name ; out: CF set <=> legal ; destroys eax push esi xor eax, eax @@: lodsb test al, al jz .done cmp al, 80h jae .big test [fat_legal_chars+eax], 1 jnz @b .err: pop esi clc ret .big: ; 0x80-0xAF, 0xE0-0xEF cmp al, 0xB0 jb @b cmp al, 0xE0 jb .err cmp al, 0xF0 jb @b jmp .err .done: sub esi, [esp] cmp esi, 257 pop esi ret fat_next_short_name: ; in: edi->8+3 name ; out: name corrected ; CF=1 <=> error pushad mov ecx, 8 mov al, '~' std push edi add edi, 7 repnz scasb pop edi cld jz .tilde ; tilde is not found, insert "~1" at end add edi, 6 cmp word [edi], ' ' jnz .insert_tilde @@: dec edi cmp byte [edi], ' ' jz @b inc edi .insert_tilde: mov word [edi], '~1' popad ; clc ; CF already cleared ret .tilde: push edi add edi, 7 xor ecx, ecx @@: ; after tilde may be only digits and trailing spaces cmp byte [edi], '~' jz .break cmp byte [edi], ' ' jz .space cmp byte [edi], '9' jnz .found dec edi jmp @b .space: dec edi inc ecx jmp @b .found: inc byte [edi] .succ: pop edi popad clc ret .break: jecxz .noplace inc edi mov al, '1' @@: xchg al, [edi] inc edi cmp al, ' ' mov al, '0' jnz @b jmp .succ .noplace: dec edi cmp edi, [esp] jz .err add dword [esp], 8 mov word [edi], '~1' inc edi inc edi @@: mov byte [edi], '0' inc edi cmp edi, [esp] jb @b pop edi popad ;clc ; automatically ret .err: pop edi popad stc ret fat_gen_short_name: ; in: esi->long name ; edi->buffer (8+3=11 chars) ; out: buffer filled pushad mov eax, ' ' push edi stosd stosd stosd pop edi xor eax, eax push 8 pop ebx lea ecx, [edi+8] .loop: lodsb test al, al jz .done call char_toupper cmp al, ' ' jz .space cmp al, 80h ja .big test [fat_legal_chars+eax], 2 jnz .symbol .inv_symbol: mov al, '_' or bh, 1 .symbol: cmp al, '.' jz .dot .normal_symbol: dec bl jns .store mov bl, 0 .space: or bh, 1 jmp .loop .store: stosb jmp .loop .big: cmp al, 0xB0 jb .normal_symbol cmp al, 0xE0 jb .inv_symbol cmp al, 0xF0 jb .normal_symbol jmp .inv_symbol .dot: test bh, 2 jz .firstdot pop ebx add ebx, edi sub ebx, ecx push ebx cmp edi, ecx jbe .skip @@: dec edi mov al, ' ' xchg al, [edi] dec ebx mov [ebx], al cmp edi, ecx ja @b .skip: mov bh, 3 jmp @f .firstdot: cmp bl, 8 jz .space push edi or bh, 2 @@: mov edi, ecx mov bl, 3 jmp .loop .done: test bh, 2 jz @f pop edi @@: lea edi, [ecx-8] test bh, 1 jz @f call fat_next_short_name @@: popad ret ;---------------------------------------------------------------- ; ; fs_RamdiskRewrite - LFN variant for writing ramdisk ; fs_RamdiskCreateFolder - create folder on ramdisk ; ; esi points to file/folder name ; ebx ignored (reserved) ; ecx number of bytes to write, 0+ (ignored for folders) ; edx mem location to data (ignored for folders) ; ; ret ebx = number of written bytes ; eax = 0 ok read or other = errormsg ; ;-------------------------------------------------------------- @@: mov eax, ERROR_ACCESS_DENIED xor ebx, ebx ret fs_RamdiskCreateFolder: mov al, 1 ; create folder jmp fs_RamdiskRewrite.common fs_RamdiskRewrite: xor eax, eax ; create file .common: cmp byte [esi], 0 jz @b pushad xor ebp, ebp push esi @@: lodsb test al, al jz @f cmp al, '/' jnz @b lea ebp, [esi-1] jmp @b @@: pop esi test ebp, ebp jnz .noroot push ramdisk_root_extend_dir push ramdisk_root_next_write push ebp push ramdisk_root_first push ramdisk_root_next jmp .common1 .noroot: ; check existence mov byte [ebp], 0 call rd_find_lfn mov byte [ebp], '/' lea esi, [ebp+1] jnc @f mov eax, ERROR_FILE_NOT_FOUND .ret1: mov [esp+28], eax popad xor ebx, ebx ret @@: test byte [edi+11], 0x10 ; must be directory mov eax, ERROR_ACCESS_DENIED jz .ret1 movzx ebp, word [edi+26] ; ebp=cluster mov eax, ERROR_FAT_TABLE cmp ebp, 2 jb .ret1 cmp ebp, 2849 jae .ret1 push ramdisk_notroot_extend_dir push ramdisk_notroot_next_write push ebp push ramdisk_notroot_first push ramdisk_notroot_next .common1: call fat_find_lfn jc .notfound ; found test byte [edi+11], 10h jz .exists_file ; found directory; if we are creating directory, return OK, ; if we are creating file, say "access denied" add esp, 20 popad test al, al mov eax, ERROR_ACCESS_DENIED jz @f mov al, 0 @@: xor ebx, ebx ret .exists_file: ; found file; if we are creating directory, return "access denied", ; if we are creating file, delete existing file and continue cmp byte [esp+20+28], 0 jz @f add esp, 20 popad mov eax, ERROR_ACCESS_DENIED xor ebx, ebx ret @@: ; delete FAT chain push edi xor eax, eax mov dword [edi+28], eax ; zero size xchg ax, word [edi+26] ; start cluster test eax, eax jz .done1 @@: cmp eax, 0xFF8 jae .done1 lea edi, [RAMDISK_FAT + eax*2] ; position in FAT xor eax, eax xchg ax, [edi] jmp @b .done1: pop edi call get_time_for_file mov [edi+22], ax call get_date_for_file mov [edi+24], ax mov [edi+18], ax or byte [edi+11], 20h ; set 'archive' attribute jmp .doit .notfound: ; file is not found; generate short name call fat_name_is_legal jc @f add esp, 20 popad mov eax, ERROR_FILE_NOT_FOUND xor ebx, ebx ret @@: sub esp, 12 mov edi, esp call fat_gen_short_name .test_short_name_loop: push esi edi ecx mov esi, edi lea eax, [esp+12+12+8] mov [eax], ebp call dword [eax-4] jc .found .test_short_name_entry: cmp byte [edi+11], 0xF jz .test_short_name_cont mov ecx, 11 push esi edi repz cmpsb pop edi esi jz .short_name_found .test_short_name_cont: lea eax, [esp+12+12+8] call dword [eax-8] jnc .test_short_name_entry jmp .found .short_name_found: pop ecx edi esi call fat_next_short_name jnc .test_short_name_loop .disk_full: add esp, 12+20 popad mov eax, ERROR_DISK_FULL xor ebx, ebx ret .found: pop ecx edi esi ; now find space in directory ; we need to save LFN <=> LFN is not equal to short name <=> generated name contains '~' mov al, '~' push ecx edi mov ecx, 8 repnz scasb push 1 pop eax ; 1 entry jnz .notilde ; we need ceil(strlen(esi)/13) additional entries = floor((strlen(esi)+12+13)/13) total xor eax, eax @@: cmp byte [esi], 0 jz @f inc esi inc eax jmp @b @@: sub esi, eax add eax, 12+13 mov ecx, 13 push edx cdq div ecx pop edx .notilde: push -1 push -1 ; find successive entries in directory xor ecx, ecx push eax lea eax, [esp+12+8+12+8] mov [eax], ebp call dword [eax-4] pop eax .scan_dir: cmp byte [edi], 0 jz .free cmp byte [edi], 0xE5 jz .free xor ecx, ecx .scan_cont: push eax lea eax, [esp+12+8+12+8] call dword [eax-8] pop eax jnc .scan_dir push eax lea eax, [esp+12+8+12+8] call dword [eax+8] ; extend directory pop eax jnc .scan_dir add esp, 8+8+12+20 popad mov eax, ERROR_DISK_FULL xor ebx, ebx ret .free: test ecx, ecx jnz @f mov [esp], edi mov ecx, [esp+8+8+12+8] mov [esp+4], ecx xor ecx, ecx @@: inc ecx cmp ecx, eax jb .scan_cont ; found! ; calculate name checksum push esi ecx mov esi, [esp+8+8] mov ecx, 11 xor eax, eax @@: ror al, 1 add al, [esi] inc esi loop @b pop ecx esi pop edi pop dword [esp+8+12+8] ; edi points to last entry in free chunk dec ecx jz .nolfn push esi push eax mov al, 40h .writelfn: or al, cl mov esi, [esp+4] push ecx dec ecx imul ecx, 13 add esi, ecx stosb mov cl, 5 call .read_symbols mov ax, 0xF stosw mov al, [esp+4] stosb mov cl, 6 call .read_symbols xor eax, eax stosw mov cl, 2 call .read_symbols pop ecx lea eax, [esp+8+8+12+8] call dword [eax+4] ; next write xor eax, eax loop .writelfn pop eax pop esi .nolfn: xchg esi, [esp] mov ecx, 11 rep movsb mov word [edi], 20h ; attributes sub edi, 11 pop esi ecx add esp, 12 mov byte [edi+13], 0 ; tenths of a second at file creation time call get_time_for_file mov [edi+14], ax ; creation time mov [edi+22], ax ; last write time call get_date_for_file mov [edi+16], ax ; creation date mov [edi+24], ax ; last write date mov [edi+18], ax ; last access date and word [edi+20], 0 ; high word of cluster and word [edi+26], 0 ; low word of cluster - to be filled and dword [edi+28], 0 ; file size - to be filled cmp byte [esp+20+28], 0 jz .doit ; create directory mov byte [edi+11], 10h ; attributes: folder mov ecx, 32*2 mov edx, edi .doit: push edx push ecx push edi add edi, 26 ; edi points to low word of cluster push edi jecxz .done mov ecx, 2849 mov edi, RAMDISK_FAT .write_loop: ; allocate new cluster xor eax, eax repnz scasw jnz .disk_full2 dec edi dec edi lea eax, [edi-(RAMDISK_FAT)] shr eax, 1 ; eax = cluster mov word [edi], 0xFFF ; mark as last cluster xchg edi, [esp] stosw pop edi push edi inc ecx ; write data cmp byte [esp+16+20+28], 0 jnz .writedir shl eax, 9 add eax, RAMDISK+31*512 .writefile: mov ebx, edx xchg eax, ebx push ecx mov ecx, 512 cmp dword [esp+12], ecx jae @f mov ecx, [esp+12] @@: call memmove add edx, ecx sub [esp+12], ecx pop ecx jnz .write_loop .done: mov ebx, edx pop edi edi ecx edx sub ebx, edx mov [edi+28], ebx add esp, 20 mov [esp+16], ebx popad xor eax, eax ret .disk_full2: mov ebx, edx pop edi edi ecx edx sub ebx, edx mov [edi+28], ebx add esp, 20 mov [esp+16], ebx popad push ERROR_DISK_FULL pop eax ret .writedir: mov edi, eax shl edi, 9 add edi, RAMDISK+31*512 mov esi, edx mov ecx, 32/4 push ecx rep movsd mov dword [edi-32], '. ' mov dword [edi-32+4], ' ' mov dword [edi-32+8], ' ' mov byte [edi-32+11], 10h mov word [edi-32+26], ax mov esi, edx pop ecx rep movsd mov dword [edi-32], '.. ' mov dword [edi-32+4], ' ' mov dword [edi-32+8], ' ' mov byte [edi-32+11], 10h mov eax, [esp+16+8] mov word [edi-32+26], ax pop edi edi ecx edx add esp, 20 popad xor eax, eax xor ebx, ebx ret .read_symbol: or ax, -1 test esi, esi jz .retFFFF lodsb test al, al jnz ansi2uni_char xor eax, eax xor esi, esi .retFFFF: ret .read_symbols: call .read_symbol stosw loop .read_symbols ret ;---------------------------------------------------------------- ; ; fs_RamdiskWrite - LFN variant for writing to 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 write, 0+ ; edx mem location to data ; ; ret ebx = bytes written (maybe 0) ; eax = 0 ok write or other = errormsg ; ;-------------------------------------------------------------- @@: push ERROR_ACCESS_DENIED fs_RamdiskWrite.ret0: pop eax xor ebx, ebx ret fs_RamdiskWrite: cmp byte [esi], 0 jz @b pushad call rd_find_lfn jnc .found popad push ERROR_FILE_NOT_FOUND jmp .ret0 .found: ; must not be directory test byte [edi+11], 10h jz @f popad push ERROR_ACCESS_DENIED jmp .ret0 @@: ; FAT does not support files larger than 4GB test ebx, ebx jz .l1 cmp dword [ebx+4], 0 jz @f .eof: popad push ERROR_END_OF_FILE jmp .ret0 @@: mov ebx, [ebx] .l1: ; now edi points to direntry, ebx=start byte to write, ; ecx=number of bytes to write, edx=data pointer call fat_update_datetime ; extend file if needed add ecx, ebx jc .eof ; FAT does not support files larger than 4GB push 0 ; return value=0 cmp ecx, [edi+28] jbe .length_ok cmp ecx, ebx jz .length_ok call ramdisk_extend_file jnc .length_ok ; ramdisk_extend_file can return two error codes: FAT table error or disk full. ; First case is fatal error, in second case we may write some data mov [esp], eax cmp al, ERROR_DISK_FULL jz .disk_full pop eax mov [esp+28], eax popad xor ebx, ebx ret .disk_full: ; correct number of bytes to write mov ecx, [edi+28] cmp ecx, ebx ja .length_ok .ret: pop eax mov [esp+28], eax ; eax=return value sub edx, [esp+20] mov [esp+16], edx ; ebx=number of written bytes popad ret .length_ok: ; now ebx=start pos, ecx=end pos, both lie inside file sub ecx, ebx jz .ret movzx edi, word [edi+26] ; starting cluster .write_loop: sub ebx, 0x200 jae .next_cluster push ecx neg ebx cmp ecx, ebx jbe @f mov ecx, ebx @@: mov eax, edi shl eax, 9 add eax, 0x100000+31*512+0x200 sub eax, ebx mov ebx, eax mov eax, edx call memmove xor ebx, ebx add edx, ecx sub [esp], ecx pop ecx jz .ret .next_cluster: movzx edi, word [edi*2+0x280000] jmp .write_loop ramdisk_extend_file.zero_size: xor eax, eax jmp ramdisk_extend_file.start_extend ; extends file on ramdisk to given size, new data area is filled by 0 ; in: edi->direntry, ecx=new size ; out: CF=0 => OK, eax=0 ; CF=1 => error, eax=code (ERROR_FAT_TABLE or ERROR_DISK_FULL) ramdisk_extend_file: push ecx ; find the last cluster of file movzx eax, word [edi+26] ; first cluster mov ecx, [edi+28] jecxz .zero_size @@: sub ecx, 0x200 jbe @f mov eax, [eax*2+0x280000] and eax, 0xFFF jz .fat_err cmp eax, 0xFF8 jb @b .fat_err: pop ecx push ERROR_FAT_TABLE pop eax stc ret @@: push eax mov eax, [eax*2+0x280000] and eax, 0xFFF cmp eax, 0xFF8 pop eax jb .fat_err ; set length to full number of sectors and make sure that last sector is zero-padded sub [edi+28], ecx push eax edi mov edi, eax shl edi, 9 lea edi, [edi+0x100000+31*512+0x200+ecx] neg ecx xor eax, eax rep stosb pop edi eax .start_extend: pop ecx ; now do extend push edx esi mov esi, 0x280000+2*2 ; start scan from cluster 2 mov edx, 2847 ; number of clusters to scan .extend_loop: cmp [edi+28], ecx jae .extend_done ; add new sector push ecx mov ecx, edx push edi mov edi, esi jecxz .disk_full push eax xor eax, eax repnz scasw pop eax jnz .disk_full mov word [edi-2], 0xFFF mov esi, edi mov edx, ecx sub edi, 0x280000 shr edi, 1 dec edi ; now edi=new cluster test eax, eax jz .first_cluster mov [0x280000+eax*2], di jmp @f .first_cluster: pop eax ; eax->direntry push eax mov [eax+26], di @@: push edi shl edi, 9 add edi, 0x100000+31*512 xor eax, eax mov ecx, 512/4 rep stosd pop eax ; eax=new cluster pop edi ; edi->direntry pop ecx ; ecx=required size add dword [edi+28], 0x200 jmp .extend_loop .extend_done: mov [edi+28], ecx pop esi edx xor eax, eax ; CF=0 ret .disk_full: pop edi ecx pop esi edx stc push ERROR_DISK_FULL pop eax ret fat_update_datetime: call get_time_for_file mov [edi+22], ax ; last write time call get_date_for_file mov [edi+24], ax ; last write date mov [edi+18], ax ; last access date ret ;---------------------------------------------------------------- ; ; fs_RamdiskSetFileEnd - set end of file on ramdisk ; ; esi points to filename ; ebx points to 64-bit number = new file size ; ecx ignored (reserved) ; edx ignored (reserved) ; ; ret eax = 0 ok or other = errormsg ; ;-------------------------------------------------------------- fs_RamdiskSetFileEnd: cmp byte [esi], 0 jnz @f .access_denied: push ERROR_ACCESS_DENIED jmp .ret @@: push edi call rd_find_lfn jnc @f pop edi push ERROR_FILE_NOT_FOUND .ret: pop eax ret @@: ; must not be directory test byte [edi+11], 10h jz @f pop edi jmp .access_denied @@: ; file size must not exceed 4Gb cmp dword [ebx+4], 0 jz @f pop edi push ERROR_END_OF_FILE jmp .ret @@: ; set file modification date/time to current call fat_update_datetime mov eax, [ebx] cmp eax, [edi+28] jb .truncate ja .expand pop edi xor eax, eax ret .expand: push ecx mov ecx, eax call ramdisk_extend_file pop ecx pop edi ret .truncate: mov [edi+28], eax push ecx movzx ecx, word [edi+26] test eax, eax jz .zero_size ; find new last sector @@: sub eax, 0x200 jbe @f movzx ecx, word [0x280000+ecx*2] jmp @b @@: ; zero data at the end of last sector push ecx mov edi, ecx shl edi, 9 lea edi, [edi+0x100000+31*512+eax+0x200] mov ecx, eax neg ecx xor eax, eax rep stosb pop ecx ; terminate FAT chain lea ecx, [0x280000+ecx+ecx] push dword [ecx] mov word [ecx], 0xFFF pop ecx and ecx, 0xFFF jmp .delete .zero_size: and word [edi+26], 0 .delete: ; delete FAT chain starting with ecx ; mark all clusters as free cmp ecx, 0xFF8 jae .deleted lea ecx, [0x280000+ecx+ecx] push dword [ecx] and word [ecx], 0 pop ecx and ecx, 0xFFF jmp .delete .deleted: pop ecx pop edi xor eax, eax ret fs_RamdiskGetFileInfo: cmp byte [esi], 0 jnz @f mov eax, 2 ; unsupported ret @@: push edi call rd_find_lfn fs_GetFileInfo_finish: jnc @f pop edi mov eax, ERROR_FILE_NOT_FOUND ret @@: push esi ebp xor ebp, ebp mov esi, edx and dword [esi+4], 0 call fat_entry_to_bdfe2 pop ebp esi pop edi xor eax, eax ret fs_RamdiskSetFileInfo: cmp byte [esi], 0 jnz @f mov eax, 2 ; unsupported ret @@: push edi call rd_find_lfn jnc @f pop edi mov eax, ERROR_FILE_NOT_FOUND ret @@: call bdfe_to_fat_entry pop edi xor eax, eax ret ;---------------------------------------------------------------- ; ; fs_RamdiskExecute - LFN variant for executing on sys floppy ; ; esi points to ramdisk filename (e.g. 'launcher') ; ebp points to full filename (e.g. '/rd/1/launcher') ; dword [ebx] = flags ; dword [ebx+4] = cmdline ; ; ret ebx,edx destroyed ; eax > 0 - PID, < 0 - error ; ;-------------------------------------------------------------- fs_RamdiskExecute: mov edx, [ebx] mov ebx, [ebx+4] test ebx, ebx jz @f add ebx, std_application_base_address @@: ;---------------------------------------------------------------- ; ; fs_RamdiskExecute.flags - second entry ; ; esi points to ramdisk filename (kernel address) ; ebp points to full filename ; edx flags ; ebx cmdline (kernel address) ; ; ret eax > 0 - PID, < 0 - error ; ;-------------------------------------------------------------- .flags: cmp byte [esi], 0 jnz @f ; cannot execute root! mov eax, -ERROR_ACCESS_DENIED ret @@: push edi call rd_find_lfn jnc .found pop edi mov eax, -ERROR_FILE_NOT_FOUND ret .found: movzx eax, word [edi+26] ; cluster push eax push dword [edi+28] ; size push .DoRead call fs_execute add esp, 12 pop edi ret .DoRead: ; read next block ; in: eax->parameters, edi->buffer ; out: eax = error code pushad cmp dword [eax], 0 ; file size jz .eof mov edx, [eax+4] ; cluster lea esi, [edx+31] shl esi, 9 add esi, 0x100000 mov ecx, 512/4 rep movsd mov ecx, [eax] sub ecx, 512 jae @f add edi, ecx neg ecx push eax xor eax, eax rep stosb pop eax @@: mov [eax], ecx mov dx, [edx*2+0x280000] mov [eax+4], dx ; high word is already zero popad xor eax, eax ret .eof: popad mov eax, 6 ret ;---------------------------------------------------------------- ; ; fs_RamdiskDelete - delete file or empty folder from ramdisk ; ; esi points to filename ; ; ret eax = 0 ok or other = errormsg ; ;-------------------------------------------------------------- fs_RamdiskDelete: cmp byte [esi], 0 jnz @f ; cannot delete root! .access_denied: push ERROR_ACCESS_DENIED .pop_ret: pop eax ret @@: and [rd_prev_sector], 0 and [rd_prev_prev_sector], 0 push edi call rd_find_lfn jnc .found pop edi push ERROR_FILE_NOT_FOUND jmp .pop_ret .found: cmp dword [edi], '. ' jz .access_denied2 cmp dword [edi], '.. ' jz .access_denied2 test byte [edi+11], 10h jz .dodel ; we can delete only empty folders! movzx eax, word [edi+26] push ebx mov ebx, eax shl ebx, 9 add ebx, RAMDISK + 31*0x200 + 2*0x20 .checkempty: cmp byte [ebx], 0 jz .empty cmp byte [ebx], 0xE5 jnz .notempty add ebx, 0x20 test ebx, 0x1FF jnz .checkempty movzx eax, word [RAMDISK_FAT + eax*2] test eax, eax jz .empty mov ebx, eax shl ebx, 9 add ebx, RAMDISK + 31*0x200 jmp .checkempty .notempty: pop ebx .access_denied2: pop edi jmp .access_denied .empty: pop ebx .dodel: movzx eax, word [edi+26] ; delete folder entry mov byte [edi], 0xE5 ; delete LFN (if present) .lfndel: test edi, 0x1FF jnz @f cmp [rd_prev_sector], 0 jz @f cmp [rd_prev_sector], -1 jz .lfndone mov edi, [rd_prev_sector] push [rd_prev_prev_sector] pop [rd_prev_sector] or [rd_prev_prev_sector], -1 shl edi, 9 add edi, RAMDISK + 31*0x200 + 0x200 @@: sub edi, 0x20 cmp byte [edi], 0xE5 jz .lfndone cmp byte [edi+11], 0xF jnz .lfndone mov byte [edi], 0xE5 jmp .lfndel .lfndone: ; delete FAT chain test eax, eax jz .done lea eax, [RAMDISK_FAT + eax*2] push dword [eax] and word [eax], 0 pop eax and eax, 0xFFF jmp .lfndone .done: pop edi xor eax, eax ret ; \end{diamond}