112 lines
1.6 KiB
NASM
112 lines
1.6 KiB
NASM
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; DCASM.ASM
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;
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; Created 31-Jul-96 [JonT]
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PAGE 60, 255
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.MODEL small, pascal
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TITLE DCASM.ASM
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.386
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.DATA
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extrn g_dwEntrypoint:DWORD
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szName DB 'DCAPVXD ', 0
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.CODE
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extrn OpenDriver:FAR
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extrn CloseDriver:FAR
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PUBLIC _OpenDriver
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_OpenDriver::
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jmp OpenDriver
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PUBLIC _CloseDriver
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_CloseDriver::
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jmp CloseDriver
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; ReturnSel
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; Returns either CS or DS to the C caller
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ReturnSel PROC NEAR PASCAL, fCS:WORD
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mov ax, ds
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cmp fCS, 0
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jz RS_Done
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mov ax, cs
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RS_Done:
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ret
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ReturnSel ENDP
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; GetVxDEntrypoint
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; Returns device entrypoint in DX:AX or zero on error
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GetVxDEntrypoint PROC NEAR PASCAL uses si di
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; Get the entrypoint from the VMM
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xor bx, bx
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mov ax, 1684h
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push ds
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pop es
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mov di, OFFSET szName
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int 2Fh
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; Return entrypoint in EAX
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mov dx, es
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mov ax, di
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ret
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GetVxDEntrypoint ENDP
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; SetWin32Event
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; Sets a Win32 event using the VxD
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SetWin32Event PROC NEAR PASCAL, pev:DWORD
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; Call the VxD. Note that pev is already a flat pointer
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mov ah, 1
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mov ecx, pev
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call [g_dwEntrypoint]
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ret
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SetWin32Event ENDP
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; _CloseVxDHandle
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; Calls the VxD to close a VxD handle. This is really torturous
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; since it's just going to call into KERNEL32, but there's no
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; export to do this from ring 3. Go figure.
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_CloseVxDHandle PROC FAR PASCAL USES ds, pev:DWORD
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mov ax, DGROUP
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mov ds, ax
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mov ah, 2
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mov ecx, pev
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call [g_dwEntrypoint]
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ret
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_CloseVxDHandle ENDP
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; ZeroMemory
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;
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; Since we can't call CRT, does a memset(lp, 0, len)
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ZeroMemory PROC NEAR PASCAL USES di, lp:DWORD, len:WORD
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les di, lp
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xor eax, eax
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mov cx, len
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shr cx, 2
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rep stosd
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mov cx, len
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and cx, 3
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rep stosb
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ret
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ZeroMemory ENDP
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END
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