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;******************************************************************************
;* Copyright 1991 Advanced Micro Devices, Inc.
;*
;* This software is the property of Advanced Micro Devices, Inc  (AMD)  which
;* specifically  grants the user the right to modify, use and distribute this
;* software provided this notice is not removed or altered.  All other rights
;* are reserved by AMD.
;*
;* AMD MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARD TO THIS
;* SOFTWARE.  IN NO EVENT SHALL AMD BE LIABLE FOR INCIDENTAL OR CONSEQUENTIAL
;* DAMAGES IN CONNECTION WITH OR ARISING FROM THE FURNISHING, PERFORMANCE, OR
;* USE OF THIS SOFTWARE.
;*
;* Comments about this software should be directed to udi@amd.com. If access
;* to electronic mail isn't available, send mail to:
;*
;* Advanced Micro Devices, Inc.
;* 29K Support Products
;* Mail Stop 573
;* 5900 E. Ben White Blvd.
;* Austin, TX 78741
;*****************************************************************************
;*       $Id: dosdfe.asm,v 1.1.1.1 2001-05-18 11:27:55 markom Exp $
;*       $Id: @(#)dosdfe.asm    2.5, AMD
;*
IFNDEF  DOS386
        DOSSEG
ENDIF
        INCLUDE udidos.ah
IFDEF   DOS386

rmcode  segment byte public use16
rmcode  ends
rmdata  segment dword public use16
rmdata  ends
pmdata  segment dword public use32
pmdata  ends
pmcode  segment byte public use32
pmcode  ends
dgroup  group   rmdata,pmdata



rmcode  segment

;
; Symbol marking start of real mode code & data,
; used at link time to specify the real mode
; code & data size
;
        public  start_real
start_real label        byte

rmcode  ends



;
; Data that needs to be accessed in both real
; mode and protected mode
;
rmdata  segment


        public code_selector, data_selector, call_prot
        ; these get filled in by protected mode startup code

code_selector  DW ?
data_selector  DW ?
call_prot       DD ?

rmdata  ends




rmdata  segment

        public  TermStruct              ; No auto underscore for Watcom C or HighC386
TermStruct      DOSTerm <>              ; Don't initialize, it will get filled at run time.
        public  UDITerminate            ; need this so we can set up real addr into TermSTruct

rmdata  ends

rmcode  segment


ELSE    ; not DOS386

        PUBLIC  _TermStruct
        .MODEL  LARGE
        .DATA   
_TermStruct  DOSTerm <UDITerminate>
        .CODE

ENDIF  ; DOS386




UDITerminate    PROC    FAR
;
; Retrieve registers from save area
IFDEF   DOS386
        ASSUME  CS:rmcode
        mov     bx, OFFSET TermStruct   ; in 386 mode, the pointer we pass to TIP
                                        ; has UDITerminate seg = seg(rmcode)
        mov     ax, cs
ELSE    ; not DOS386
        mov     bx, OFFSET _TermStruct
        mov     ax, DGROUP
ENDIF   ; DOS386
        mov     es, ax
        mov     ss, es:[bx].sss
        mov     sp, es:[bx].ssp
        mov     ds, es:[bx].sds
        mov     si, es:[bx].ssi
        mov     di, es:[bx].sdi
        mov     bp, es:[bx].sbp
        mov     ax, es:[bx].retval
        ret                             ; far return because of PROC FAR

UDITerminate ENDP

IFDEF   DOS386

rmcode  ends



pmcode segment


        ASSUME CS:pmcode
        ASSUME DS:dgroup

        public  GetCS
GetCS   PROC NEAR
        mov     ax, cs
        ret
GetCS   ENDP

        public  GetDS
GetDS   PROC NEAR
        mov     ax, ds
        ret
GetDS   ENDP


        public  _exp_call_to
_exp_call_to PROC NEAR
        push    ebp
        mov     ebp, esp
        push    es              ; save at least all regs required by hc386
        push    gs
        push    fs
        push    ds      
        push    ebx
        push    esi
        push    edi
        mov     ebx, [ebp+8]
        mov     ax, [ebx+0ah]   ; new ss,ds,etc.
        mov     ecx, [ebx+6]    ; new sp
        sub     ecx, 256        ; back up past TIPname space
        mov     es, ax
        mov     gs, ax
        mov     fs, ax
        mov     ds, ax
        mov     edx, esp
        mov     si, ss  ; save old ss:sp
        mov     ss, ax
        mov     esp, ecx
        ; now on new stack, save old stack
        push    edx
        push    si
        call    fword ptr cs:[ebx]
        ; restore old stack
        pop     si
        pop     edx
        mov     ss,si
        mov     esp,edx
        ; now we are back on original stack
        pop     edi
        pop     esi
        pop     ebx
        pop     ds
        pop     fs
        pop     gs
        pop     es
        pop     ebp
        ret                     ; eax will be the return

_exp_call_to ENDP


pmcode ends



rmdata   segment
;
; Symbol marking end of real mode code & data,
; used at link time to specify the real mode
; code & data size
;
        public  end_real
end_real label  byte
rmdata   ends

ENDIF   ; DOS386

        END