TITLE 'RxDOS Boot Sector Program' PAGE 59, 132 .LALL ;'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''; ; RxDOS Boot Sector Program ; ;...............................................................; ;'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''; ; Real Time Dos ; ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -; ; ; ; This material was created as a published version of a DOS ; ; equivalent product. This program logically functions in ; ; the same way as MSDOS functions and it is internal data ; ; structure compliant with MSDOS 6.0 ; ; ; ; This product is distributed AS IS and contains no warranty ; ; whatsoever, including warranty of merchantability or ; ; fitness for a particular purpose. ; ; ; ; ; ; (c) Copyright 1990, 1997. Api Software and Mike Podanoffsky ; ; All Rights Reserved Worldwide. ; ; ; ; This product is protected under copyright laws and may not ; ; be reproduced in whole or in part, in any form or media, ; ; included but not limited to source listing, facsimile, data ; ; transmission, cd-rom, or floppy disk without the expressed ; ; written consent of the author. ; ; ; ; License for distribution for commercial use or resale ; ; required from: ; ; ; ; Api Software ; ; 12 South Walker Street ; ; Lowell, MA 01851 ; ; ; ; internet: mikep@world.std.com ; ; ; ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -; ; Compile with MASM 5.1 ; ;...............................................................; include rxdosmac.asm include rxdosdef.asm RxDOSBOOT SEGMENT PUBLIC 'CODE' assume cs:RxDOSBOOT, ds:RxDOSBOOT, es:RxDOSBOOT, ss:RxDOSBOOT ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; Stack Arguments ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - even _rootDirectory dd ? _sizeRootDirectory dw ? _readDrive dw ? _readTrack dw ? _readSector dw ? _readHead dw ? _diskParameterTable db 12 dup(?) _stackReserved equ ($ - _diskParameterTable) + 20h ROMBIOS_DISKTABLE equ ( 1Eh * 4 ) ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; buffers start elsewhere ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - org 500h RXDOS_READBUFFER: org 700h RXDOS_DOSLOADBUFFER: ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; assume starts at 0000:7C00 ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - org 7C00h RxDOS_START: jmp RxDOS_LOAD ; this information is standard for every boot sector __bsOemName db 'RxDOS6.0' ; 'RxDOS' if formatted by us __bsBytesPerSector dw ? ; 512 is default __bsSectorsPerCluster db ? __bsResSectors dw ? __bsNumCopiesFAT db ? __bsMaxAllocRootDir dw ? __bsMaxSectors dw ? ; if zero, see huge sectors __bsMediaDescriptor db ? __bsSectorsPerFat dw ? __bsSectorsPerTrack dw ? __bsHeads dw ? __bsHiddenSectors dd ? __bsHugeSectors dd ? __bsDriveNumber db 0 db 0 __bsBootSignature db 29h ; 29h if extended boot sector __bsVolumeId dd 0 ; unique disk ID __bsVolumeLabel db sizeVolumeLabel dup(' '); not same as DOS Volume Id __bsFileSystemType db 'FAT12 ' ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; the RxDOS boot process begins here ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - RxDOS_LOAD: cli ; no interrupts cld ; all that we need to init xor ax, ax mov ds, ax ; allow debugging mov es, ax ; allow debugging mov ss, ax ; allow debugging mov sp, 7C00h - _stackReserved mov bp, sp mov byte ptr [ _readDrive ][ bp ], dl mov bx, offset ROMBIOS_DISKTABLE ; int 1E lds si, es:[ bx ] ; 0000:0078 lea di, offset [ _diskParameterTable ][ bp ] mov word ptr es:[ _pointer ][ bx ], di mov word ptr es:[ _segment ][ bx ], ss mov cx, sizeDISKPARAM rep movsb sti xor ax, ax mov ds, ax mov byte ptr [ _diskParameterTable. _dptHeadSettleTime ][ bp ], 15 mov cx, word ptr [ __bsSectorsPerTrack ] mov byte ptr [ _diskParameterTable. _dptSectorsPerTrack ][ bp ], cl int 13h ; reset disk drive (ax = 0) jc RxDOSLOAD_Error ; if error --> ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; if no huge sectors, fix up huge sectors ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - mov ax, word ptr [ __bsMaxSectors ] or ax, ax ; not a huge address disk ? jz RxDOSLOAD_08 ; yes --> mov word ptr [ __bsHugeSectors ], ax ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; compute logical sector address of Root Directory ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - RxDOSLOAD_08: mov bp, sp ; restore stack frame. xor ax, ax mov al, byte ptr [ __bsNumCopiesFAT ] mul word ptr [ __bsSectorsPerFat ] add ax, word ptr [ __bsHiddenSectors. _low ] adc dx, word ptr [ __bsHiddenSectors. _high ] add ax, word ptr [ __bsResSectors ] adc dx, 0000 mov word ptr [ _rootDirectory. _low ][ bp ], ax mov word ptr [ _rootDirectory. _high ][ bp ], dx ; read first sector of Root Directory mov bx, offset RXDOS_READBUFFER call RxDOSPerformRead jc RxDOSLOAD_Error ; if error --> mov di, offset RXDOS_READBUFFER mov si, offset RxDOS_RXDOSBIOCOM mov cx, sizeFILENAME rep cmpsb ; compare first name jnz RxDOSLOAD_Error ; if not a system disk --> mov di, offset (RXDOS_READBUFFER. sizeDIRENTRY) mov cx, sizeFILENAME rep cmpsb ; compare second name jz RxDOSLOAD_LoadDOS ; if equal --> ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; can't load ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - RxDOSLOAD_Error: mov si, offset RxDOS_DISKERROR call RxDOSLOAD_DisplayMsg xor ax, ax int 16h ; wait on any key int 19h ; not expected to return jmp RxDOSLOAD_Error ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; load DOS ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - RxDOSLOAD_LoadDOS: mov ax, word ptr [ __bsMaxAllocRootDir ] add ax, (sizeSector / sizeDIRENTRY) - 1 mov cl, 4 shr ax, cl ; sectors used by directory mov word ptr [ _sizeRootDirectory ][ bp ], ax ; save size mov ax, word ptr [ RXDOS_READBUFFER. deStartCluster ] dec ax dec ax ; subtract 2 xor ch, ch mov cl, [ __bsSectorsPerCluster ] mul cx add ax, word ptr [ _rootDirectory. _low ][ bp ] adc dx, word ptr [ _rootDirectory. _high ][ bp ] add ax, word ptr [ _sizeRootDirectory ][ bp ] adc dx, 0000 mov bx, offset RXDOS_DOSLOADBUFFER ; where to load mov cx, 3 ; read three sectors RxDOSLOAD_LoadDOS_08: call RxDOSPerformRead jc RxDOSLOAD_Error ; if error --> add bx, word ptr [ __bsBytesPerSector ] add ax, 0001 adc dx, 0000 loop RxDOSLOAD_LoadDOS_08 mov ch, byte ptr [ __bsMediaDescriptor ] mov dl, byte ptr [ _readDrive ][ bp ] mov bx, word ptr [ _rootDirectory. _low ][ bp ] mov ax, word ptr [ _rootDirectory. _high ][ bp ] lea si, offset [ _diskParameterTable ][ bp ] JMP_FAR 70h, 0000h ; RXDOS_DOSLOADBUFFER ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; Display Message, wait for ANY key ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - RxDOSLOAD_DisplayMsg: lodsb ; get character (ds:si) or al, al ; null terminator ? jz RxDOSLOAD_Return ; done --> push si mov ah, 0Eh mov bx, 0007h int 10h pop si jmp RxDOSLOAD_DisplayMsg RxDOSLOAD_Return: ret ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; perform disk read ; --------------------------------------------------------------- ; dx:ax logical sector to read ; es:bx read buffer address ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - RxDOSPerformRead: push bp push dx push ax push cx div word ptr [ __bsSectorsPerTrack ] inc dl mov byte ptr [ _readSector ][ bp ], dl xor dx, dx div word ptr [ __bsHeads ] ; mov word ptr [ _readHead ][ bp ], ax ; don't need to save heads ; mov byte ptr [ _readTrack ][ bp ], dl ; dont need to save track mov dh, dl ; track clc mov cl, 6 shl ah, cl ; move read head up or ah, byte ptr [ _readSector ][ bp ] ; unused portion of sector mov cx, ax xchg ch, cl mov ax, 0201h ; read one sector. mov dl, byte ptr [ _readDrive ][ bp ] int 13h jnc RxDOSPerformRead_08 cmp ax, 11h ; ECC corrected data ? jz RxDOSPerformRead_08 ; return no carry --> stc RxDOSPerformRead_08: pop cx pop ax pop dx pop bp ret RxDOS_RXDOSBIOCOM: db 'RXDOSBIOSYS' RxDOS_RXDOSCOM: db 'RXDOS SYS' RxDOS_DISKERROR: db 'Not an RxDOS system disk or disk error', 0Dh, 0Ah db 'Press any key to continue...', 0Dh, 0Ah, 00h ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; partition table ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - org RxDOS_START+200h-2 RxDOS_BootSignature: db 055h, 0AAh ;'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''; ; Write Stub ; ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -; ; ; ; The stub loads at the normal 100h load address and writes ; ; the boot sector to drive A: ; ;...............................................................; org 100h RxDOS_WRITESTUB: cli cld push cs pop ss mov sp, offset RxDOS_WRITESTUB_STACK sti mov dx, cs mov ds, dx ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; see if drive specified ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Entry def _drive, 0000 ; A: def _WriteOnce, FALSE def _SilentMode, FALSE def _isRemovable, TRUE mov si, offset 80h mov cl, byte ptr es:[ si ] or cl, cl ; arguments passed in command line ? jz RxDOS_WRITESTUB_36 ; no, default to A: --> ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; switch processing ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - RxDOS_WRITESTUB_06: inc si mov al, byte ptr es:[ si ] ; scan command line cmp al, ControlM ; command line end ? jz RxDOS_WRITESTUB_36 ; yes --> cmp al, ' ' ; space ? jz RxDOS_WRITESTUB_06 ; skip any leading spaces --> cmp al, '-' ; switch character ? jz RxDOS_WRITESTUB_10 ; yes --> cmp al, '/' ; switch character ? jnz RxDOS_WRITESTUB_22 ; no --> ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; see if -1 (write once ) ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - RxDOS_WRITESTUB_10: inc si mov al, byte ptr es:[ si ] ; get switch character cmp al, '1' ; write once ? jnz RxDOS_WRITESTUB_12 ; no --> storarg _WriteOnce, TRUE ; set write once mode jmp RxDOS_WRITESTUB_06 ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; see if -s (silent mode) ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - RxDOS_WRITESTUB_12: cmp al, 's' ; silent mode ? jz RxDOS_WRITESTUB_14 ; yes --> cmp al, 'S' ; silent mode ? jnz RxDOS_WRITESTUB_16 ; no --> RxDOS_WRITESTUB_14: storarg _SilentMode, TRUE ; set silent mode storarg _WriteOnce, TRUE ; silent makes -> write once mode jmp RxDOS_WRITESTUB_06 RxDOS_WRITESTUB_16: cmp al, ControlM ; command line end ? jnz RxDOS_WRITESTUB_06 ; not yet --> jmp short RxDOS_WRITESTUB_36 ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; drive letter processing ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - RxDOS_WRITESTUB_22: mov bl, al ; get character sub bl, '0' ; allow 0 as A: jc RxDOS_WRITESTUB_36 ; cmp al, '9' + 1 ; allow number for drive jc RxDOS_WRITESTUB_32 ; mov bl, al sub bl, 'A' ; A - Z jc RxDOS_WRITESTUB_36 ; cmp al, 'Z' + 1 ; jc RxDOS_WRITESTUB_32 ; mov bl, al sub bl, 'a' ; a - z jc RxDOS_WRITESTUB_36 ; cmp al, 'z' + 1 ; jc RxDOS_WRITESTUB_32 ; jmp RxDOS_WRITESTUB_InvalidDrive ; cannot set invalid drive --> ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; get drive code, test if removable ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - RxDOS_WRITESTUB_32: mov byte ptr [ _drive ][ bp ], bl ; set drive if other than A: RxDOS_WRITESTUB_36: mov bl, byte ptr [ _drive ][ bp ] inc bl Int21 IoControl, 08h ; is drive removable ? ifc RxDOS_WRITESTUB_InvalidDrive ; invalid drive --> not ax ; 0000 if removable, and ax, 1 ; ... convert to true or false mov word ptr [ _isRemovable ][ bp ], ax ; mov bl, byte ptr [ _drive ][ bp ] inc bl Int21 IoControl, 09h ; is drive remote ? jc RxDOS_WRITESTUB_40 ; ignore possible unsupported error --> test dx, 1000h ; remote flag set ? ifnz RxDOS_WRITESTUB_InvalidDrive ; cannot set invalid drive --> ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; Write message ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - RxDOS_WRITESTUB_40: mov dl, byte ptr [ _drive ][ bp ] add dl, 'A' mov byte ptr RxDOS_PressKeyWhenReady_Drive, dl cmp word ptr [ _SilentMode ][ bp ], 0 ; silent mode ? jnz RxDOS_WRITESTUB_46 ; ok to write --> mov si, offset RxDOS_PressKeyWhenReady call RxDOSLOAD_DisplayMsg RxDOS_WRITESTUB_42: xor ax, ax int 16h ; wait for keyboard command cmp al, ControlM jz RxDOS_WRITESTUB_46 cmp al, ' ' jz RxDOS_WRITESTUB_46 cmp al, 'n' ifz RxDOS_WRITESTUB_80 ; if no --> cmp al, 'N' ifz RxDOS_WRITESTUB_80 ; if no --> cmp al, 'C'-40h ifz RxDOS_WRITESTUB_80 ; if no --> jmp RxDOS_WRITESTUB_42 ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; if floppy drive, ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - RxDOS_WRITESTUB_46: push cs pop es ; restore es: RxDOS_WRITESTUB_48: mov dl, byte ptr [ _drive ][ bp ] call _ReadBootSector ; read current information jc RxDOS_WRITESTUB_68 ; if error --> cld mov si, offset [ _rwBUFFER. _bsBytesPerSector ] mov di, offset [ __bsBytesPerSector ] mov cx, ( __bsDriveNumber - __bsBytesPerSector ) rep movsb ; copy these parameters mov si, offset [ RxDOS_OEMNAME ] mov di, offset [ __bsOemName ] mov cx, 8 rep movsb ; copy product name push es xor ax, ax mov es, ax mov ax, word ptr es:[ 46Ch ] mov dx, word ptr es:[ 46Eh ] pop es mov word ptr [ __bsVolumeId. _High ], dx mov word ptr [ __bsVolumeId. _Low ], ax xor dx, dx mov dl, byte ptr [ _drive ][ bp ] call _WriteBootSector ; write boot sector jnc RxDOS_WRITESTUB_72 ; if everything is ok --> RxDOS_WRITESTUB_68: mov si, offset RxDOS_diskA_NotReadyOrError call RxDOSLOAD_DisplayMsg jmp short RxDOS_WRITESTUB_76 ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; success. try again ? ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - RxDOS_WRITESTUB_72: mov si, offset RxDOS_diskA_WrittenSuccesfully call RxDOSLOAD_DisplayMsg cmp word ptr [ _WriteOnce ][ bp ], TRUE jz RxDOS_WRITESTUB_80 mov si, offset RxDOS_diskA_WriteAnother call RxDOSLOAD_DisplayMsg RxDOS_WRITESTUB_76: xor ax, ax int 16h ; wait for keyboard command cmp al, 'n' jz RxDOS_WRITESTUB_80 ; if no --> cmp al, 'N' jz RxDOS_WRITESTUB_80 ; if no --> cmp al, 'C'-40h jz RxDOS_WRITESTUB_80 ; if cancel --> jmp RxDOS_WRITESTUB_40 ; else if retry --> RxDOS_WRITESTUB_80: Int21 TerminateProcess, 00 ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; messages ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - RxDOS_WRITESTUB_InvalidDrive: mov si, offset RxDOS_InvalidDrive call RxDOSLOAD_DisplayMsg Int21 TerminateProcess, 02 jmp RxDOS_WRITESTUB_InvalidDrive ;'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''; ; Read Boot Sector for ANY drive ; ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -; ; ; ; Usage: ; ; dx drive ( 0 = A:, 1 = B:, 2 = C:, ... ) ; ; ; ; ; ; ; ;...............................................................; _ReadBootSector: Entry def _drive, dx ; 0 = A:, 1 = B:, 2 = C:, ... def _retries, 3 ; max retries ddef _drivePB ; drive parameter block ddef _strategy ddef _interrupt push ds mov dl, byte ptr [ _drive ][ bp ] inc dl ; 1 = A:, ... Int21 GetDriveParameterBlock ; get pointer to drive data stordarg _drivePB, ds, bx ; drive parameter bloc pop ds cmp al, -1 ; invalid drive or error ? jnz _ReadBootSector_08 ; no, ok --> stc Return _ReadBootSector_08: mov bx, offset _ReqBlock mov byte ptr [ rwrLength ][ bx ], sizeREADReqHeader mov byte ptr [ rwrFunction ][ bx ], DEVICEREAD mov al, byte ptr [ _drive ][ bp ] mov byte ptr [ rwrUnit ][ bx ], al getdarg es, si, _drivePB ; drive parameter bloc mov al, byte ptr es:[ _dpbMediaDescriptor ][ si ] mov byte ptr [ rwrMediaID ][ bx ], al mov word ptr [ rwrBytesReq ][ bx ], 1 ; one sector mov word ptr [ rwrStartSec ][ bx ], 0000 ; address mov word ptr [ rwrHugeStartSec. _high ][ bx ], 0000 mov word ptr [ rwrHugeStartSec. _low ][ bx ], 0000 mov word ptr [ rwrBuffer. _pointer ][ bx ], offset _rwBUFFER mov word ptr [ rwrBuffer. _segment ][ bx ], cs mov word ptr [ rwrVolumeID. _pointer ][ bx ], offset _rwVOLBUFFER mov word ptr [ rwrVolumeID. _segment ][ bx ], cs les bx, dword ptr es:[ _dpbptrDeviceDriver ][ si ] mov ax, word ptr es:[ devStrategy ][ bx ] stordarg _strategy, es, ax mov ax, word ptr es:[ devInterrupt ][ bx ] stordarg _interrupt, es, ax _ReadBootSector_18: push ds pop es mov bx, offset _ReqBlock mov word ptr [ rwrStatus ][ bx ], 0000 call dword ptr [ _strategy ][ bp ] ; strategy call dword ptr [ _interrupt ][ bp ] ; interrupt ; dec word ptr [ _retries ][ bp ] ; retries ; jnz _ReadBootSector_18 clc Return ;'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''; ; Write Boot Sector for ANY drive ; ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -; ; ; ; Usage: ; ; dx drive ( 0 = A:, 1 = B:, 2 = C:, ... ) ; ; ; ;...............................................................; _WriteBootSector: Entry def _drive, dx ; 0 = A:, 1 = B:, 2 = C:, ... def _retries, 3 ; max retries ddef _drivePB ; drive parameter block ddef _strategy ddef _interrupt push ds mov dl, byte ptr [ _drive ][ bp ] inc dl ; 1 = A:, ... Int21 GetDriveParameterBlock ; get pointer to drive data stordarg _drivePB, ds, bx ; drive parameter bloc pop ds cmp al, -1 ; invalid drive or error ? jnz _WriteBootSector_08 ; no, ok --> stc Return _WriteBootSector_08: mov bx, offset _ReqBlock mov byte ptr [ rwrLength ][ bx ], sizeREADReqHeader mov byte ptr [ rwrFunction ][ bx ], DEVICEWRITE mov word ptr [ rwrStatus ][ bx ], 0000 mov al, byte ptr [ _drive ][ bp ] mov byte ptr [ rwrUnit ][ bx ], al getdarg es, si, _drivePB ; drive parameter bloc mov al, byte ptr es:[ _dpbMediaDescriptor ][ si ] mov byte ptr [ rwrMediaID ][ bx ], al mov word ptr [ rwrBytesReq ][ bx ], 1 ; one sector mov word ptr [ rwrStartSec ][ bx ], 0000 ; address mov word ptr [ rwrHugeStartSec. _high ][ bx ], 0000 mov word ptr [ rwrHugeStartSec. _low ][ bx ], 0000 mov word ptr [ rwrBuffer. _pointer ][ bx ], offset RxDOS_START mov word ptr [ rwrBuffer. _segment ][ bx ], cs mov word ptr [ rwrVolumeID. _pointer ][ bx ], offset _rwVOLBUFFER mov word ptr [ rwrVolumeID. _segment ][ bx ], cs les bx, dword ptr es:[ _dpbptrDeviceDriver ][ si ] mov ax, word ptr es:[ devStrategy ][ bx ] stordarg _strategy, es, ax mov ax, word ptr es:[ devInterrupt ][ bx ] stordarg _interrupt, es, ax _WriteBootSector_18: push ds pop es mov bx, offset _ReqBlock call dword ptr [ _strategy ][ bp ] ; strategy call dword ptr [ _interrupt ][ bp ] ; interrupt ; dec word ptr [ _retries ][ bp ] ; retries ; jnz _WriteBootSector_18 clc Return ;'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''; ; Messages ; ;...............................................................; RxDOS_OEMNAME: db 'RxDOS6.0' RxDOS_Welcome: db 0Dh, 0Ah db 0Dh, 0Ah, 'RxDOS Write Boot Sector Utility. ' db 0Dh, 0Ah, 'Usage: rxd_boot [drive]' db 0Dh, 0Ah, 0 RxDOS_PressKeyWhenReady: db 0Dh, 0Ah, 0Dh, 0Ah, 'Press Space to write boot sector on disk ' RxDOS_PressKeyWhenReady_Drive: db 'A. ', 0 RxDOS_diskA_WriteAnother: db 0Dh, 0Ah, 'Disk updated. Would you like to write another? ', 0 RxDOS_diskA_WrittenSuccesfully: db 0Dh, 0Ah, 'Disk updated. ', 0 RxDOS_diskA_NotReadyOrError: db 0Dh, 0Ah, 'Disk error or drive not ready. Try again? ', 0 RxDOS_InvalidDrive: db 0Dh, 0Ah, 'Drive is invalid. Cannot write boot sector. ', 0 ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; stack for stub ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - even dw 400h dup(0) RxDOS_WRITESTUB_STACK: dw 0 ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; Drive Default Data ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - DriveDefaultData: ; 360k drive dw sizeSector ; __bsBytesPerSector db 2 ; __bsSectorsPerCluster dw 1 ; __bsResSectors db 2 ; __bsNumCopiesFAT dw 112 ; __bsMaxAllocRootDir dw 720 ; __bsMaxSectors db 0FDh ; __bsMediaDescriptor dw 2 ; __bsSectorsPerFat dw 9 ; __bsSectorsPerTrack dw 2 ; __bsHeads dd 0 ; __bsHiddenSectors dd 0 ; __bsHugeSectors ; 1.2M drive dw sizeSector ; __bsBytesPerSector db 1 ; __bsSectorsPerCluster dw 1 ; __bsResSectors db 2 ; __bsNumCopiesFAT dw 224 ; __bsMaxAllocRootDir dw 2400 ; __bsMaxSectors db 0F9h ; __bsMediaDescriptor dw 7 ; __bsSectorsPerFat dw 15 ; __bsSectorsPerTrack dw 2 ; __bsHeads dd 0 ; __bsHiddenSectors dd 0 ; __bsHugeSectors ; 720k drive dw sizeSector ; __bsBytesPerSector db 2 ; __bsSectorsPerCluster dw 1 ; __bsResSectors db 2 ; __bsNumCopiesFAT dw 112 ; __bsMaxAllocRootDir dw 1440 ; __bsMaxSectors db 0F9h ; __bsMediaDescriptor dw 3 ; __bsSectorsPerFat dw 9 ; __bsSectorsPerTrack dw 2 ; __bsHeads dd 0 ; __bsHiddenSectors dd 0 ; __bsHugeSectors ; 1.44M drive dw sizeSector ; __bsBytesPerSector db 1 ; __bsSectorsPerCluster dw 1 ; __bsResSectors db 2 ; __bsNumCopiesFAT dw 224 ; __bsMaxAllocRootDir dw 2880 ; __bsMaxSectors db 0F0h ; __bsMediaDescriptor dw 9 ; __bsSectorsPerFat dw 18 ; __bsSectorsPerTrack dw 2 ; __bsHeads dd 0 ; __bsHiddenSectors dd 0 ; __bsHugeSectors dw -1 ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; working sector buffer ;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - even _ReqBlock: db sizeREADReqHeader dup(0) _rwBUFFER: db sizeSector dup(0) _rwVOLBUFFER: db sizeSector dup(0) RxDOSBOOT ENDS END RxDOS_WRITESTUB