source: cmedia/trunk/Drv16/vddentry.asm@ 577

; $Id: vddentry.asm,v 1.3 2001/03/22 18:13:01 sandervl Exp $

.386
.seq

include         ..\include\segments.inc


_TEXT       SEGMENT DWORD PUBLIC USE16 'CODE'
            assume cs:cgroup, ds:dgroup


; Route VDD IDC request to C code to implement
; 16:16 entry from 16:32 caller
;
; Called from VDD using pascal calling conventions:
;       Parms pushed left to right, callee clears the stack
;
ulFunc  EQU DWORD PTR [bp+18]   ; Pascal conventions push parms left to right
ul1     EQU DWORD PTR [bp+14]   ; 8 bytes for 16:32 far return address
ul2     EQU DWORD PTR [bp+10]   ; 2 bytes for save of callers stack frame ptr

        PUBLIC  IDCENTRY_VDD
        EXTERN  IDCENTRY_VDD_C:near
IDCENTRY_VDD PROC FAR  ; 16:16 entry from 16:32 ; VDD calls PDD
        push    bp
        mov     bp, sp
        push    ds
        push    es
        mov     ax, seg _DATA
        push    ulFunc                          ; pascal calling convention
        mov     ds, ax
        push    ul1
        push    ul2
        call    IDCENTRY_VDD_C
        shl     edx, 16                         ; Move DX:AX return value
        movzx   eax, ax                         ; into eax
        pop     es
        pop     ds
        or      eax, edx
        leave
        db      66h                             ; Force next instruction 32-bit
        ret     12                              ; 16:32 far return, pop parms
IDCENTRY_VDD ENDP




usCmd   EQU WORD PTR [bp+10]    ; cdecl conventions push parms right to left
pPacket EQU DWORD PTR [bp+14]   ; 8 bytes for 16:32 far return address

        PUBLIC  _OSSIDC_ENTRY
        EXTERN  OSSIDC_ENTRYPOINT:near
_OSSIDC_ENTRY PROC FAR  ; 16:16 entry from 16:32 ; called from 32 bits pdd
        push    bp
        mov     bp, sp
        push    ds
        push    es
        mov     ax, seg _DATA
        push    usCmd                           ; pascal calling convention
        mov     ds, ax
        push    pPacket
        call    OSSIDC_ENTRYPOINT
        shl     edx, 16                         ; Move DX:AX return value
        movzx   eax, ax                         ; into eax
        pop     es
        pop     ds
        or      eax, edx
        leave
        db      66h                             ; Force next instruction 32-bit
        ret                                     ; 16:32 far return
_OSSIDC_ENTRY ENDP



; hook procedure is called with parameter in EAX
; we only need the lower part ...

;       PUBLIC  HookHandlerAsm_
;       EXTERN  _HookHandler:near
;HookHandlerAsm_ PROC FAR
;       pushad
;       push    ds
;       push    es
;       mov     bx, seg _DATA
;       mov     ds, bx
;       push    ax
;       call    _HookHandler
;       add     sp, 2
;       pop     es
;       pop     ds
;       popad
;       retf
;HookHandlerAsm_ ENDP



; hook procedure is called with parameter in EAX
; since we use a pointer to a WAVESTREAM instance
; here, we can directly call WAVESTREAM::Process

        PUBLIC  ProcessHookStub_
        EXTERN  `W?Process$:WAVESTREAM$n()v`:near
ProcessHookStub_ PROC FAR
        pushad
        push    ds
        push    es
        mov     bx, seg _DATA
        mov     ds, bx
        call    `W?Process$:WAVESTREAM$n()v`    ; AX: pointer to WAVESTREAM instance
        pop     es
        pop     ds
        popad
        retf
ProcessHookStub_ ENDP




;       PUBLIC  _inpd
;_inpd proc near
;       in   eax, dx
;       mov  dx, ax
;       shr  eax, 16
;       xchg dx, ax
;       ret
;_inpd endp



;       PUBLIC  _outpd
;_outpd proc near
;       mov ax, cx
;       shl eax, 16
;       mov ax, bx
;       out dx, eax
;       ret
;_outpd endp


_TEXT   ENDS



END