example1.asm

XLIB 2.0版 32位应用程序开发 ASM/C语言的DOS 扩展库

               .MODEL        LARGE,PASCAL
               .386P

               INCLUDE        XLIB.INC       ;Include XLIB public symbols
               INCLUDELIB     XLIB.LIB       ;Link with XLIB.LIB

               .STACK         1024
               .CODE
               .STARTUP
               CALL           INITXLIB       ;Initialize XLIB
               OR             EAX,EAX        ;EAX = 0 if successful
               JZ             INITDONE
               .EXIT          0              ;Initialization failed
INITDONE:      PUSHD          OFFSET DEMOPROC
               CALL           CALLPM         ;Execute DEMOPROC in protected
               .EXIT          0

;Protected-mode routines must be placed in following segment:
TSEG           SEGMENT PARA PUBLIC USE32 'CODE'
               ASSUME CS:TSEG, SS:TSEG, DS:TSEG, ES:TSEG, FS:DSEG, GS:DGROUP

;Protected-mode routine to print message to the screen using DOS function.
DEMOPROC       PROC NEAR
               MOV            EBX,OFFSET PMMSG
               MOV            AH,02H
MSGLOOP:       MOV            DL,CS:[EBX]    ;32-bit offset!!!!!
               OR             DL,DL
               JZ             EXIT
               INT            21H            ;Print character with DOS
               INC            EBX
               JMP            MSGLOOP
EXIT:          RET                           ;Go back to real or V86 mode
PMMSG          DB  "In 32-bit protected mode!!!  "
               DB  "Returning to real mode.",10,13,0
DEMOPROC       ENDP

TSEG           ENDS
               END