diff options
Diffstat (limited to 'private/mvdm/vdd/samples/mscdex/tsr/mscdexnt.asm')
| -rw-r--r-- | private/mvdm/vdd/samples/mscdex/tsr/mscdexnt.asm | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/private/mvdm/vdd/samples/mscdex/tsr/mscdexnt.asm b/private/mvdm/vdd/samples/mscdex/tsr/mscdexnt.asm new file mode 100644 index 000000000..ca0ff46a1 --- /dev/null +++ b/private/mvdm/vdd/samples/mscdex/tsr/mscdexnt.asm @@ -0,0 +1,246 @@ + name mscdexnt +; +; MSCDEXNT +; +; Author: Neil Sandlin (neilsa) +; +; Description: +; +; This TSR implements the v86 mode portion of MSCDEX support under +; NT. Basically, all this piece does is hook INT2F and watch for +; MSCDEX calls. When the first one occurs, it tries to load VCDEX.DLL. +; If that succeeds, it passes the call (and all subsequent calls) +; to VCDEX for processing. +; + include isvbop.inc + include mscdexnt.inc + +_TEXT segment word public 'CODE' + assume cs:_TEXT,ds:_TEXT,es:_TEXT + +;*----------------------- TSR Code --------------------------* + +DrvStrat proc far ; Strategy Routine + ret +DrvStrat endp + +DrvIntr proc far ; INterrupt routine + ret +DrvIntr endp + +;****************************************************************************** +; +; Int2FHook +; +; +;****************************************************************************** +Int2FHook proc near + + cmp ah, MSCDEX_ID ;MSCDEX? + jnz int2fchain ;no + cmp al, MAX_MSCDEX_CMD ;command too high? + ja int2fchain ;yes + + cmp word ptr cs:[hVDD], 0 ;zero is an invalid module handle + jnz callvdd ;registered ok + + cmp byte ptr cs:[fVDDChecked],1 + jz vddfailed + + call RegisterVDD + jc vddfailed ;didn't get it + +callvdd: + push ax ;put ax on stack + mov ax, word ptr cs:[hVDD] + DispatchCall + add sp, 2 ;vdd has set ax accordingly + iret ;svc handled, return to caller + +vddfailed: + or al,al + jnz try_0b + xor bx,bx + jmp short int2f_done +try_0b: + cmp al,0bh + jne int2f_done +;; williamh - June 1 1993 - if unable to load VDD, we should tell +;; the caller that the drive is NOT a cd rom. + xor ax, ax + mov bx,0adadh +int2f_done: + iret + +int2fchain: + jmp dword ptr cs:[oldint] + +Int2FHook endp + +;**************************************************************************** +; +; RegisterVDD +; +;**************************************************************************** +RegisterVDD proc near + + push ax + push bx + push cx + push dx + push si + push di + push ds + push es + + + mov ax, cs + mov ds, ax + mov es, ax + ; Load vcdex.dll + mov si, offset DllName ; ds:si = dll name + mov di, offset InitFunc ; es:di = init routine + mov bx, offset DispFunc ; ds:bx = dispatch routine + + push cs ; pass far pointer to headers + pop cx ; in cx:dx + mov dx, offset drive_header + + RegisterModule + jc errorexit ; jif error + mov cs:[hVDD],ax ; save handle + +errorexit: + mov byte ptr cs:[fVDDChecked],1 + pop es + pop ds + pop di + pop si + pop dx + pop cx + pop bx + pop ax + ret + +RegisterVDD endp + +;*----------------------- TSR Data Area ---------------------* +oldint dd 0 +hVDD DW 0 + +fVDDChecked DB 0 ; 0 - VDD never called. 1 - VDD once called. + +DllName DB "VCDEX.DLL",0 +InitFunc DB "VDDRegisterInit",0 +DispFunc DB "VDDDispatch",0 + + + ALIGN 16 +drive_header: + DrvHd 'MSCDEX00' + + ALIGN 16 +Init_Fence: +;*-------------------------- Initialization Code ----------------------* + +mscdexnt proc far + + ; at this point es,ds -> PSP + ; SS:SP points to stack + + ; first check that we are running under NT + + mov ax, GET_NT_VERSION + int 21h + cmp bl, NT_MAJOR_VERSION + je cdx_chk_more + jmp cdx_badver +cdx_chk_more: + cmp bh, NT_MINOR_VERSION + je cdx_ver_ok + jmp cdx_badver + +cdx_ver_ok: + ; Now check that this TSR is'nt already installed + mov ah,MSCDEX_ID + mov al,0bh ; call function 0b + int MPX_INT ; int 2f + + cmp bx,0adadh + jne cdx_chks_done + jmp cdx_installed + +cdx_chks_done: + + ; free the env segment + + push es + push ds + mov es, es:[2ch] + mov ah, 49h + int 21h + + mov ah, DOS_GET_VECTOR + mov al, MPX_INT ; 2f + int 21h ; get old vector + mov WORD PTR cs:oldint,bx ; save old vector here + mov WORD PTR cs:oldint+2,es + + mov dx, offset Int2FHook + push cs ; get current code segment + pop ds + mov ah, DOS_SET_VECTOR + mov al, MPX_INT ; vector to hook + int 21h ; hook that vector + +; +; Compute size of TSR area +; + pop ds + pop es + mov dx, offset Init_Fence ; end of fixed TSR code + mov cl, 4 ; divide by 16 + shr dx, cl + add dx, 16 ; add in PSP +; +; Terminate and stay resident +; + mov ah, DOS_TSR ; TSR + mov al, 0 + int 21h ; TSR + +cdx_badver: + mov dx, offset Message1 + push cs + pop ds + mov ah,09h + int 21h + jmp short cdx_exit + +cdx_installed: + mov dx, offset Message2 + push cs + pop ds + mov ah,09h + int 21h + +cdx_exit: + mov ax,4c00h ; Exit + int 21h + +mscdexnt endp + + include messages.inc + +_TEXT ends + +InitStack segment para stack 'STACK' + + dw 256 dup (?) + +top_of_stack equ $ + +InitStack ends + + end mscdexnt + |