diff options
Diffstat (limited to 'contrib/syslinux/syslinux-4.03/dosutil/eltorito.asm')
| -rw-r--r-- | contrib/syslinux/syslinux-4.03/dosutil/eltorito.asm | 1099 |
1 files changed, 0 insertions, 1099 deletions
diff --git a/contrib/syslinux/syslinux-4.03/dosutil/eltorito.asm b/contrib/syslinux/syslinux-4.03/dosutil/eltorito.asm deleted file mode 100644 index d6b6b50..0000000 --- a/contrib/syslinux/syslinux-4.03/dosutil/eltorito.asm +++ /dev/null @@ -1,1099 +0,0 @@ - -;----------------------------------------------------------------------------- -; ElTorito.asm -; -; El Torito Bootable CD-ROM driver which does not reset the CD-ROM drive upon -; loading, but instead accesses the drive through BIOS system calls -; -; MIT License -; -; (c) 2000 by Gary Tong -; (c) 2001-2009 by Bart Lagerweij -; -; Permission is hereby granted, free of charge, to any person obtaining a copy -; of this software and associated documentation files (the "Software"), to deal -; in the Software without restriction, including without limitation the rights -; to use, copy, modify, merge, publish, distribute, sublicense, and/or sell -; copies of the Software, and to permit persons to whom the Software is -; furnished to do so, subject to the following conditions: -; -; The above copyright notice and this permission notice shall be included in -; all copies or substantial portions of the Software. -; -; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR -; IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, -; FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE -; AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER -; LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, -; OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN -; THE SOFTWARE. -; -;----------------------------------------------------------------------------- - -; To assemble and link, use these commands with NASM 2.x: -; nasm -Ox -f bin -o eltorito.sys eltorito.asm - -; To enable Trace markers uncomment the line below -; DEBUG_TRACERS=1 - -; To enable debug info uncomment the line below -; DEBUG=1 - -%ifdef DEBUG_TRACERS - %macro TRACER 1 - call debug_tracer - db %1 - %endmacro -%else - %macro TRACER 1 - %endmacro -%endif ; DEBUG_TRACERS - -%define Ver '1.5' -%define CR 0DH, 0Ah -RPolyH equ 0EDB8h -RPolyL equ 08320h - - section .text align=16 - org 0 - -;============================================================================= - -Cdrom: - -NextDriver dd -1 ;-+ -Attributes dw 0C800h ; | -Pointers dw Strategy ; | - dw Commands ; | MSCDEX requires this -DeviceName db 'ELTORITO' ; | data in these locations - dw 0 ; | -DriveLetter db 0 ; | -NumUnitsSupp db 1 ;-+ - -DriverName db 'El-Torito CD-ROM Device Driver',0 - align 4, db 0 -ReqHdrLoc dd 0 -XferAddr dd 0 -Checksum dd -1 -DriveNumber db 0 -ReadBytes db 0 ;0 --> 2048 bytes/sector - ;1 --> 1024 bytes/sector - ;2 --> 512 bytes/sector - -Routines dw Init ;Init ;0 - dw Unsupported ;MediaCheck ;1 - dw Unsupported ;BuildBPB ;2 - dw IoctlInput ;IoctlInput ;3 - dw Unsupported ;Input ;4 - dw Unsupported ;NonDesInput ;5 - dw Unsupported ;InputStatus ;6 - dw Unsupported ;InputFlush ;7 - dw Unsupported ;Output ;8 - dw Unsupported ;OutputVerify ;9 - dw Unsupported ;OutputStatus ;10 - dw Unsupported ;OutputFlush ;11 - dw IoctlOutput ;IoctlOutput ;12 - dw DoNothing ;DeviceOpen ;13 - dw DoNothing ;DeviceClose ;14 - dw ReadL ;ReadL ;128 - -IoctlICtrl dw Raddr ;Raddr ;0 - dw Unsupported ;LocHead ;1 - dw Unsupported ;(Reserved) ;2 - dw Unsupported ;ErrStat ;3 - dw Unsupported ;AudInfo ;4 - dw DrvBytes ;DrvBytes ;5 - dw DevStat ;DevStat ;6 - dw SectSize ;SectSize ;7 - dw VolSize ;VolSize ;8 - dw MedChng ;MedChng ;9 - -SpecPkt times 19 db 0 ; offset 77h in 1.4 - times 13 db 0 ; unknown extra 00s in 1.4 - -Greeting db 'El-Torito Bootable CD-ROM Driver for Dos v',Ver,', http://www.nu2.nu/eltorito/',CR - db ' (c) 2000 by Gary Tong',CR - db ' (c) 2001-2002 by Bart Lagerweij',CR,0 -DblSpace db ' ',0 - -;============================================================================= - -Strategy: - - mov word [cs:ReqHdrLoc],bx - mov word [cs:ReqHdrLoc+2],es - retf - - -;============================================================================= - -Commands: - - push ax - push bx - push cx - push dx - push si - push di - push bp -; pushad - push ds - push es - TRACER 'C' - - cld ;Clear direction - sti ;Enable interrupts - - mov ax, cs ;ds=cs - mov ds, ax - - les bx,[ReqHdrLoc] ;seg:offset ptr into es:bx - xor ax,ax - mov al,[es:bx+2] ;Get Command code -%ifdef DEBUG - call print_hex8 -%endif - cmp al,15 - jb Mult2 ;If 0-14 - cmp al,128 - jb UnknownCmd ;If 15-127 - cmp al,129 - jb ShiftDown ;If 128 -UnknownCmd: mov al,121 ;8 = Unsupported (Reserved) -ShiftDown: sub al,113 ;128 --> 15, 121 --> 8 -Mult2: shl al,1 ;Convert into offset (*2) - mov di,Routines - add di,ax - call word [di] ;Execute desired command - or ax,100h ;Set Return Status's Done bit - lds bx,[ReqHdrLoc] ;seg:offset ptr into ds:bx - mov [bx+3],ax ;Save Status - -%ifdef DEBUG - cmp byte [cs:buffer+2048], 96h - je buffer_ok - mov al, '!' - call print_char - jmp $ -buffer_ok: -%endif - - TRACER 'c' - pop es - pop ds -; popad - pop bp - pop di - pop si - pop dx - pop cx - pop bx - pop ax - retf - - -;============================================================================= - -Unsupported: ;Unsupported Command - - mov ax,8003h ;Set Status Error bit, - TRACER 'U' - TRACER 'C' - retn ; Error 3 = Unknown Command - - -;============================================================================= - -IoctlInput: ;IOCTL Input Routine - - mov di,[es:bx+14] ;es:bx --> Request Header - mov es,[es:bx+16] ;Get Xfer Address into es:di - xor ax,ax ;Get Control Block Code - mov al,[es:di] -%ifdef DEBUG - TRACER 'I' - TRACER 'O' - call print_hex8 -%endif - cmp al,10 - jb UnkIoctlI ;If 0-9 - mov al,2 ;Map to Unsupported -UnkIoctlI: shl al,1 ;Convert into offset (*2) - mov si,IoctlICtrl - add si,ax - call word [si] ;Execute desired command - retn - - -;============================================================================= - -Raddr: ;Return Device Header Address - - TRACER 'A' - mov word [es:di+1],0 - mov [es:di+3],cs - xor ax, ax ;Set Return Status = success - TRACER 'a' - retn - - -;============================================================================= - -DrvBytes: ;Read Drive Bytes - - TRACER 'B' - push di ;Save original Xfer Addr - add di,2 ;Point to 1st dest byte - mov si,Greeting ;Point to Greeting -DrvB: movsb ;Copy over a byte - cmp byte [si],13 ;Is next char a CR? - jne DrvB ;Loop if not - - sub di,2 ;Get #bytes copied into ax - mov ax,di - pop di ;Retrieve original Xfer Addr - sub ax,di - mov byte [es:di+1],al ;and save it - mov ax,0 ;Set Return Status = success - TRACER 'b' - retn - - -;============================================================================= - -DevStat: ;Return Device Status - - TRACER 'D' - mov word [es:di+1],202h ;Door closed - mov word [es:di+3],0 ;Door unlocked - ;Supports only cooked reading - ;Read only - ;Data read only - ;No interleaving - ;No prefetching - ;No audio channel manipulation - ;Supports both HSG and Redbook - ; addressing modes - - xor ax, ax ;Set Return Status = success - TRACER 'd' - retn - - -;============================================================================= - -SectSize: ;Return Sector Size - - TRACER 'S' - mov word [es:di+2],2048 - mov ax,0 ;Set Return Status = success - TRACER 's' - retn - - -;============================================================================= - -VolSize: ;Return Volume Size - - TRACER 'V' - call PriVolDesc ;Get and Check Primary Volume - ; Descriptor - mov ax,800Fh ;Assume Invalid Disk Change - jc VolExit ;If Read Failure - - mov ax,word [Buffer+80] ;Read Successful - mov word [es:di+1],ax ;Copy over Volume Size - mov ax,word [Buffer+82] - mov word [es:di+3],ax - mov ax,0 ;Set Return Status = success -VolExit: - TRACER 'v' - retn - - -;============================================================================= - -MedChng: ;Return Media Changed Status - - TRACER 'M' - call PriVolDesc ;Get and Check Primary Volume - ; Descriptor - mov byte [es:di+1],-1 ;Assume Media Changed - mov ax,800Fh ; and Invalid Disk Change - jc MedExit ;If Media Changed or Bad - - mov byte [es:di+1],1 ;Media has not changed - mov ax,0 ;Set Return Status = success -MedExit: - TRACER 'm' - retn - - -;============================================================================= - -PriVolDesc: ;Get and Check Primary Volume - ; Descriptor - TRACER 'P' - mov ax,cs ;Set ds:si --> SpecPkt - mov ds,ax - - mov cx, 5 -PriVolAgain: - mov byte [SpecPkt],16 ;SpecPkt Size - mov byte [SpecPkt+1],0 ;Reserved - mov word [SpecPkt+2],1 ;Transfer one 2048-byte sector - push cx - mov cl,byte [ReadBytes] ;Multiply by 4 if reading 512 - shl word [SpecPkt+2],cl ; bytes at a time - pop cx - mov word [SpecPkt+6],cs ;Into our Buffer - mov word [SpecPkt+4], Buffer - mov word [SpecPkt+8],16 ;From CD Sector 16 - mov word [SpecPkt+10],0 - mov word [SpecPkt+12],0 - mov word [SpecPkt+14],0 - - mov si, SpecPkt - mov dl, [DriveNumber] - mov ah, 42h ;Extended Read - int 13h - jnc PriVolPass ;If success - -; TRACER '1' - ; read error - loop PriVolAgain - - TRACER '2' - ; read retries exhausted - ; flow into below - jmp PriReadErr - -PriVolPass: - mov si,Buffer ;Point input to Buffer - mov ax,-1 ;Init Checksum registers - mov bx,ax ; bx,ax = 0FFFFFFFFh - jc PriNew ;If Read Failure - - push di ;Read Successful, - ; so Calculate Checksum - mov di,1024 ;Init Word counter -PriWord: mov dx,[cs:si] ;Grab next word from buffer - mov cx,16 ;Init bit counter -PriBit: shr dx,1 ;Shift everything right 1 bit - rcr bx,1 - rcr ax,1 - jnc NoMult ;If a zero shifted out - - xor bx,RPolyH ;A one shifted out, so XOR - xor ax,RPolyL ; Checksum with RPoly -NoMult: - loop PriBit - - add si,2 ;Inc Word Pointer - dec di - ja PriWord - TRACER '3' - - pop di ;Checksum calculation complete - cmp bx,[Checksum+2] ;Has Checksum changed? - jne PriNew ;If Checksum Changed - - cmp ax,[Checksum] - jne PriNew ;If Checksum Changed - - clc ;Checksum not changed, CF=0 - mov ax,0 ;Status = success - jmp PriOld - -PriReadErr: - mov WORD [Checksum+2],bx ;Save New Checksum - mov [Checksum],ax ; or 0FFFFFFFFh if bad read - stc ;Checksum change, CF=1 - mov ax, 800bh ;Status = read fault - jmp PriOld - -PriNew: mov WORD [Checksum+2],bx ;Save New Checksum - mov [Checksum],ax ; or 0FFFFFFFFh if bad read - stc ;Checksum Changed, CF=1 - mov ax,800Fh ;Status = Invalid Media Change -PriOld: - TRACER 'p' - retn - - -;============================================================================= - -IoctlOutput: ;IOCTL Output Routine - - TRACER 'O' - mov di,[es:bx+14] ;es:bx --> Request Header - mov es,[es:bx+16] ;Get Xfer Address into es:di - xor ax,ax ;Get Control Block Code - mov al,[es:di] - cmp al,2 - jne UnkIoctlO ;If not 2 (ResetDrv) - call DoNothing ;Reset Drive - jmp IoctlODone -UnkIoctlO: - call Unsupported ;Unsupported command -IoctlODone: - TRACER 'o' - retn - - -;============================================================================= - -DoNothing: ;Do Nothing Command - - mov ax,0 ;Set Return Status = success - retn - - -;============================================================================= - -ReadL: ;Read Long Command - - TRACER 'R' - mov ax,cs ;Set ds=cs - mov ds,ax - ;es:bx --> Request Header - cmp byte [es:bx+24],0 ;Check Data Read Mode - jne ReadLErr ;If Cooked Mode - - cmp byte [es:bx+13],2 ;Check Addressing Mode - jb ReadLOK ;If HSG or Redbook Mode - -ReadLErr: - TRACER '8' - mov ax,8003h ;Set Return Status = Unknown - jmp ReadLExit ; Command Error and exit - -ReadLOK: - mov ax,[es:bx+20] ;Get Starting Sector Number, - mov dx,[es:bx+22] ; Assume HSG Addressing Mode - cmp byte [es:bx+13],0 ;Check Addressing Mode again - je ReadLHSG ;If HSG Addressing Mode - - TRACER '7' - ;Using Redbook Addressing Mode. Convert to HSG format - mov al,dl ;Get Minutes - mov dl,60 - mul dl ;ax = Minutes * 60 - add al,byte [es:bx+21] ;Add in Seconds - adc ah,0 - mov dx,75 ;dx:ax = - mul dx ; ((Min * 60) + Sec) * 75 - add al,byte [es:bx+20] ;Add in Frames - adc ah,0 - adc dx,0 - sub ax,150 ;Subtract 2-Second offset - sbb dx,0 ;dx:ax = HSG Starting Sector - -ReadLHSG: - mov word [SpecPkt+8], ax ;Store Starting - mov word [SpecPkt+10], dx ; Sector Number - mov word [SpecPkt+12], 0 ; (HSG Format) - mov word [SpecPkt+14], 0 - - mov ax,[es:bx+14] ;Get Transfer Address - mov word [SpecPkt+4],ax - mov ax,[es:bx+16] - mov word [SpecPkt+6],ax - - mov byte [SpecPkt],16 ;Size of Disk Address Packet - mov byte [SpecPkt+1],0 ;Reserved - - mov cx, 5 -ReadLAgain: - mov ax,[es:bx+18] ;Get number of sectors to read - mov word [SpecPkt+2],ax - cmp ax, 3FFFh ;Too large? - ja ReadLBad ;If yes - - push cx - mov cl,byte [ReadBytes] ;Multiply by 4 if reading 512 - shl word [SpecPkt+2],cl ; bytes at a time - pop cx - -%ifdef DEBUG - push ax - push cx - push si - mov cx, 16 - mov si,SpecPkt -ReadDump: mov al, ' ' - call print_char - mov al, byte [si] ;Hexdump a SpecPkt byte - call print_hex8 - inc si ;Point to next byte - loop ReadDump - pop si - pop cx - pop ax -%endif - mov si,SpecPkt - mov dl,[DriveNumber] - mov ah,42h ;Extended Read - int 13h - jnc ReadLGd ;If success - -;hang: -; jmp hang -; TRACER '1' - loop ReadLAgain - TRACER '2' - jmp short ReadLBad -ReadLGd: - TRACER '3' - xor ax, ax ;Status 0 = success - jmp short ReadLExit - -ReadLBad: - TRACER '9' - mov ax, 800Bh ;Set Read Fault Error - ; flow into ReadLExit -ReadLExit: - TRACER 'r' - retn - - - -%ifdef DEBUG_TRACERS -debug_tracer: pushad - pushfd - - mov al, '[' - mov ah,0Eh ;BIOS video teletype output - xor bh, bh - int 10h ;Print it - - mov bp,sp - mov bx,[bp+9*4] ; Get return address - mov al,[cs:bx] ; Get data byte - inc word [bp+9*4] ; Return to after data byte - - mov ah,0Eh ;BIOS video teletype output - xor bh, bh - int 10h ;Print it - - mov al, ']' - mov ah,0Eh ;BIOS video teletype output - xor bh, bh - int 10h ;Print it - - popfd - popad - retn -%endif - -;----------------------------------------------------------------------------- -; PRINT_HEX4 -;----------------------------------------------------------------------------- -; print a 4 bits integer in hex -; -; Input: -; AL - 4 bits integer to print (low) -; -; Output: None -; -; Registers destroyed: None -; -print_hex4: - - push ax - and al, 0fh ; we only need the first nibble - cmp al, 10 - jae hex_A_F - add al, '0' - jmp hex_0_9 -hex_A_F: - add al, 'A'-10 -hex_0_9: - call print_char - pop ax - retn - - -;----------------------------------------------------------------------------- -; print_hex8 -;----------------------------------------------------------------------------- -; print a 8 bits integer in hex -; -; Input: -; AL - 8 bits integer to print -; -; Output: None -; -; Registers destroyed: None -; -print_hex8: - - push ax - push bx - - mov ah, al - shr al, 4 - call print_hex4 - - mov al, ah - and al, 0fh - call print_hex4 - - pop bx - pop ax - retn - - -;============================================================================= -; print_hex16 - print a 16 bits integer in hex -; -; Input: -; AX - 16 bits integer to print -; -; Output: None -; -; Registers destroyed: None -;============================================================================= -print_hex16: - - push ax - push bx - push cx - - mov cx, 4 -print_hex16_loop: - rol ax, 4 - call print_hex4 - loop print_hex16_loop - - pop cx - pop bx - pop ax - retn - -;============================================================================= -; print_hex32 - print a 32 bits integer in hex -; -; Input: -; EAX - 32 bits integer to print -; -; Output: None -; -; Registers destroyed: None -;============================================================================= -print_hex32: - - push eax - push bx - push cx - - mov cx, 8 -print_hex32_loop: - rol eax, 4 - call print_hex4 - loop print_hex32_loop - - pop cx - pop bx - pop eax - retn - -;============================================================================= -; print_string - print string at current cursor location -; -; Input: -; DS:SI - ASCIIZ string to print -; -; Output: None -; -; Registers destroyed: None -;============================================================================= -print_string: - push ax - push si - -print_string_again: - mov al, [si] - or al, al - jz print_string_exit - call print_char - inc si - jmp print_string_again - -print_string_exit: - pop si - pop ax - retn - -;----------------------------------------------------------------------------- -; PRINT_CHAR -;----------------------------------------------------------------------------- -; Print's a character at current cursor position -; -; Input: -; AL - Character to print -; -; Output: None -; -; Registers destroyed: None -; -print_char: - - push ax - push bx - - mov ah,0Eh ;BIOS video teletype output - xor bh, bh - int 10h ;Print it - -print_char_exit: - pop bx - pop ax - retn - - -;============================================================================= - -;This space is used as a 2048-byte read buffer plus one test byte. -;The 96h data is used for testing the number of bytes returned by an Extended -; CD-ROM sector read - - align 16, db 0 -Buffer times 2049 db 96h - -;============================================================================= - -Init: ;Initialization Routine - - TRACER 'I' - mov ax,cs ;ds=cs - mov ds,ax - -%ifdef DEBUG -; print CS value (load segment) - call print_hex16 -%endif - - mov si, Greeting ;Display Greeting - call print_string - - mov ax,Unsupported ;Init is executed only once - mov [Routines],ax - - mov ax, 5400h - int 13h ; Get diskemu status - jc FindBoot ; If CF=1 no diskemu loaded - - mov [DriveNumber], cl ; Store drive number - - call keyflag - and al, 8 ; alt key ? - jz extread - - mov si, DrvNumMsg ; Display "drive number=" - call print_string - mov al, [DriveNumber] - call print_hex8 - mov si, LineEnd ; CR/LF - call print_string - jmp extread - -; Diskemu is not loaded -; so loop to find drive number - ; *** start of 1.4 changes *** - ; ??? mov dl, 0ffh ;Start at Drive 0xff - ; *** FindBoot at c47 in 1.4, at c0c in 1.3 *** -FindBoot: call ScanDrives ; call new helper in 1.4 - jnc FoundBoot ; ded*df3 -; mov si,offset SpecPkt ;Locate booted CD-ROM drive -; mov [SpecPkt],0 ;Clear 1st byte of SpecPkt -; mov ax,4B01h ;Get Bootable CD-ROM Status -; int 13h -; jnc FindPass ;If booted CD found -; -; Carry is not cleared in buggy Dell BIOSes, -; so I'm checking packet size byte -; some bogus bioses (Dell Inspiron 2500) returns packet size 0xff when failed -; Dell Dimension XPsT returns packet size 0x14 when OK - -; cmp [SpecPkt], 0 -; jne FoundBoot - -; cmp [SpecPkt], 13h ; anything between 13h and 20h should be OK -; jb FindFail -; cmp [SpecPkt], 20h -; ja FindFail -; jmp short FoundBoot -; -; FindFail: -; dec dl ;Next drive -; cmp dl, 80h -; jae FindBoot ;Check from ffh..80h - ; *** end of 1.4 changes *** - - mov si,NoBootCD ;No booted CD found, - call print_string - jmp NoEndAddr ;Do not install driver - -FoundBoot: -; mov dl, [SpecPkt+2] ; 1.4 change - ; *** next line at c57 in 1.4, at c3d in 1.3 *** - mov [DriveNumber],dl ;Booted CD-ROM found, - ; so save Drive # - - call keyflag - and al, 8 ; alt key ? - jz extread - - mov si, CDStat - call print_string - mov si, SpecPkt ;Point to returned CD SpecPkt - mov cx, 19 ; containing 19 bytes -StatDump: mov al, ' ' ;Print a space - call print_char - mov al, byte [si] ;Hexdump a SpecPkt byte - call print_hex8 - inc si ;Point to next byte - loop StatDump - - mov si, LineEnd ;Print a CR/LF - call print_string - -extread: -;See how many CD Sector bytes are returned by an Extended Read - mov byte [SpecPkt],16 ;SpecPkt Size - mov byte [SpecPkt+1],0 ;Reserved - mov word [SpecPkt+2],1 ;Transfer one sector - mov word [SpecPkt+6],cs ;Into our Buffer - mov word [SpecPkt+4],Buffer - mov word [SpecPkt+8],16 ;From CD Sector 16 - mov word [SpecPkt+10],0 - mov word [SpecPkt+12],0 - mov word [SpecPkt+14],0 - - mov si, SpecPkt ;Set ds:si --> SpecPkt - mov dl, [DriveNumber] - mov ah, 42h ;Extended Read - int 13h - jnc SecSize ;If success - - mov ah, 42h ;Always make 2 read attempts - int 13h - ;How many bytes did we get? -SecSize: std ;Count down - mov ax,cs ;Point to end of Buffer - mov es,ax - mov di,Buffer+2047 ;Find end of read data - mov si,Buffer+2048 - mov cx,2049 - repe cmpsb ;cx = number of bytes read - - cld ;Restore count direction to up - mov si,CDBytes ;Display number of bytes read - call print_string - - mov al, [DriveNumber] - call print_hex8 - - mov si,CDBytesA ;Remainder A of message - call print_string - - mov al,ch ;Hex-dump cx - and al,0Fh ;Second nibble - call print_hex8 ; (don't need the First) - mov al,cl - call print_hex8 ; (don't need the First) - - mov si,CDBytesB ;Remainder B of message - call print_string - - cmp cx,2048 ;Did we read 2048 bytes? - je ParseParm ;If yes <-- O.K. - - mov byte [ReadBytes],1 - cmp cx,1024 ;Did we read 1024 bytes? - je ParseParm ;If yes <-- O.K. - - mov byte [ReadBytes],2 - cmp cx,512 ;Did we read 512 bytes? - jne NoEndAddr ;If not, do not load driver - -ParseParm: mov bx,word [cs:ReqHdrLoc] ;Parse command line - mov es,word [cs:ReqHdrLoc+2] ; parameters - mov si,[es:bx+18] ;Get BPB array ptr into DS:SI - mov ds,[es:bx+20] -FindParm: inc si -FindParm1: cmp byte [si],0Dh ;CR? (End of parameters) - je EndOfParms - - cmp byte [si],0Ah ;LF? - je EndOfParms - - cmp byte [si],'/' ;A parameter? - jne FindParm - - inc si - cmp byte [si],'D' ;Device Name parameter? - jne FindParm1 - - inc si - cmp byte [si],':' - jne FindParm1 - -;bbb - push si - mov si, DevName ;Device Name is at ds:si - push ds ;Keep ptr to Device Name - mov ax, cs - mov ds, ax - call print_string - pop ds ;Retrieve Device Name ptr - pop si - mov cx, 8 ;Get next 8 chars - inc si ; = Device Name - mov ax, cs - mov es, ax - mov di, DeviceName -NextChar: cmp byte [si],' ' - ja AboveSpace - - mov ax,cs ;Pad end of Device Name with - mov ds,ax ; spaces if necessary - mov si,DblSpace ;A space -AboveSpace: mov al, [si] - call print_char - movsb ;ds:[si] --> es:[di] - loop NextChar - - mov si,LineEnd - mov ax,cs - mov ds,ax - call print_string - - mov ax,Init-2 ;Last byte of driver to keep - jmp EndAddr ;Install driver - -EndOfParms: - mov ax, cs ; Restore segment registers (fix) - mov ds, ax - mov es, ax - - mov si,NoDevName ;No Device Name Found - call print_string - -NoEndAddr: mov ax,0 ;Do not install driver - -EndAddr: mov es,[ReqHdrLoc+2] ;Write End Address - mov bx,[ReqHdrLoc] - mov [es:bx+14],ax - mov [es:bx+16],cs - mov bx,ax ;Hold onto install status - - mov si, DrvInst ;Display driver install status - call print_string - mov si, DrvInst1 ;Assume driver installed - cmp bx,0 ;Was driver installed? - jne DrvStatus ;If yes - mov si, NoDrvInst ;Driver not installed -DrvStatus: call print_string - - mov ax,0 ;Set Return Status = success - cmp bx,0 ;Was INIT successful? - jne InitStat ;If yes - mov ax,800Ch ;Status = General Failure -InitStat: - push ax ;Save Return Status - - call keyflag - and al, 8 ; alt key ? - jz InitExit - -WaitHere: - mov si, WaitMsg ;Display Halted message - call print_string - -AltWait: - call keyflag - and al, 8 ; Alt key? - jnz AltWait ; Pressed? yes -> wait - -InitExit: - pop ax ;Retrieve Return Status - TRACER 'i' - retn ;That's it for Init! - - ; *** start 1.4 changes at ded *** -SpecGo: mov si,SpecPkt - int 13h - retn - -ScanDrives: push ax ; at df3 in 1.4 - push si - mov dl, 7fh ;Start at Drive 0x80 -NextDrv: inc dl - clc - mov ax,4B01h ;Get Bootable CD-ROM Status - mov BYTE [SpecPkt],0 ;Clear 1st byte of SpecPkt - call SpecGo -; Carry is not cleared in buggy Dell BIOSes, -; so I'm checking packet size byte -; some bogus bioses (Dell Inspiron 2500) returns packet size 0xff when failed -; Dell Dimension XPsT returns packet size 0x14 when OK - - cmp BYTE [SpecPkt], 13h ; anything between 13h and 20h should be OK - jb FindFail - cmp BYTE [SpecPkt], 20h - ja FindFail ; in 1.4 at e16 - jmp short SendFound ; in 1.4 at e26 - -FindFail: cmp dl, 0ffh - je SendFail ; Check from 80h..ffh - jmp short NextDrv ;Next drive -SendFail: xor dl,dl - stc - jmp short ThingDone -SendFound: mov dl, [SpecPkt+2] - clc -ThingDone: pop si - pop ax - retn - ; *** end 1.4 changes *** - -;============================================================================= - -;------------------------------------------------------------ -; keyboard flags - return keyboard flags in AL -; bit 3 = ALT key -keyflag: ; at dbc in 1.3, at e2e in 1.4 - push bx - mov ah, 2 - int 16h - pop bx - retn - -;============================================================================= - -DrvNumMsg db ' Diskemxx.bin returned drive number=', 0 -NoBootCD db ' No booted CD-ROM found.',CR,0 - -CDStat db ' INT 13h / AX=4B01h Specification Packet for ' - db 'Booted CD-ROM:',CR,' ', 0 - -CDBytes db ' Drive ', 0 -CDBytesA db ' returns ', 0 -CDBytesB db 'h bytes per Sector.',CR,0 - -DevName db ' Device Name: ', 0 -NoDevName db ' No Device Name found. ' - db 'Usage: device=eltorito.sys /D:<DevName>',CR,0 - -DrvInst db ' Driver ', 0 -NoDrvInst db 7,'not ' ;7 = Ctrl-G = Beep -DrvInst1 db 'installed',CR,0 - -WaitMsg db ' Alt pressed, waiting...', CR, 0 -;ContMsg db ' Continuing...' -LineEnd db CR,0 - - -;============================================================================= |