;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; ;; ;; 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 ? 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 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 ; \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: ; 0x440-0x450 -> 0xE0-0xEF add al, 0xA0 .ascii: .doit: stosb jmp uni2ansi_str .done: mov byte [edi], 0 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 mov ecx, 8 push edi ebp 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 @@: 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 .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: ; 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 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 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 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 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 ; 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 = size 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 mov ebx, [edi+28] .reteof: mov eax, 6 ; EOF pop edi ret @@: mov ebx, [ebx] .l1: push dword [edi+28] ; file size push dword [edi+28] movzx edi, word [edi+26] ; cluster push ecx edx .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 @@: cmp ecx, [esp+12] jbe @f mov ecx, [esp+12] @@: mov ebx, edx call memmove add edx, ecx sub [esp], ecx sub [esp+12], ecx pop ecx xor ebx, ebx cmp [esp+8], ebx jnz .skip jecxz .done jmp .eof .skip: movzx edi, word [edi*2+0x280000] ; find next cluster from FAT jmp .new .eof: pop edx ecx ebx ebx jmp .reteof .done: pop edx ecx ebx ebx edi xor eax, eax ret ; \end{diamond}