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Assembly Source File | 1994-03-23 | 13.4 KB | 339 lines

.MODEL LARGE,PASCAL .386P ;+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ;TASM Modifications ;+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ;TASM users should set TASMMODE below to TRUE. TRUE EQU 1 FALSE EQU 0 TASMMODE = FALSE IF TASMMODE MASM51 QUIRKS NOJUMPS PUSHW MACRO IMMEDIATE16:REST ;PUSH imm16 (for TASM compatibility) IF (@WordSize EQ 4) DB 66H ENDIF DB 68H DW IMMEDIATE16 ENDM PUSHD MACRO IMMEDIATE32:REST ;PUSH imm32 (for TASM compatibility) IF (@WordSize EQ 2) DB 66H ENDIF DB 68H DD IMMEDIATE32 ENDM INCLUDE XLIBB.INC ELSE ARG TEXTEQU <> OPTION PROC:PRIVATE OPTION NOLJMP INCLUDE XLIB.INC ENDIF ;+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ;DSEG declaration. The DSEG data segment has combine type 'FAR_DATA' when ;being used in a Borland library. Under most memory models, Borland places all ;segments with combine type 'DATA' in DGROUP. Unfortunately, the offsets seen ;by the library in such segments may have a different base than those seen by C. ;+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ IF TASMMODE DSEG SEGMENT PARA PUBLIC USE16 'FAR_DATA' ELSE DSEG SEGMENT PARA PUBLIC USE16 'DATA' ENDIF ASSUME DS:DSEG ;+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ;Stacks used for MOVMEM routine. Stacks are dynamically allocated to cover the ;possibility that MOVMEM is called both within the main thread of execution and ;in interrupt handlers. The possibility of nested interrupts is also covered. ;Calls to MOVMEM may be nested four deep. Each dynamically allocated stack ;contains 100H bytes. ;+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ALIGN 8 DB 800H DUP(0) ;Sufficient space for four stacks ISTKPTR DD OFFSET $ ;Initial stack pointer (dynamically adjusted) STKALLOC EQU 200H ;Number of bytes allocated per stack for MOVMEM DSEG ENDS CSEG SEGMENT PARA PUBLIC USE16 'CODE' ASSUME CS:CSEG IF TASMMODE SMALLSTACK ENDIF ;Allocate extended memory block. Error code returned in DX:AX. Arguments are: ;NOBYTES:DWORD = Number of bytes to allocate ;ADRPTR:DWORD = Far pointer to linear address of allocated block ;SIZEPTR:DWORD = Far pointer to size of allocated block ;HANDLEPTR:DWORD = Far pointer to handle of allocated block XMALLOC PROC FAR, ARG NOBYTES:DWORD,ADRPTR:DWORD,SIZEPTR:DWORD,HANDLEPTR:DWORD ;Number of bytes to allocate PUSH EBX PUSH ECX PUSH DS MOV EAX,NOBYTES CALL GETMEM OR EAX,EAX JNZ SHORT EXIT PUSH EBX LDS BX,ADRPTR MOV [BX],EDX LDS BX,SIZEPTR MOV [BX],ECX LDS BX,HANDLEPTR POP DWORD PTR [BX] EXIT: PUSH EAX ;Return error code in DX:AX POP AX POP DX POP DS POP ECX POP EBX RET XMALLOC ENDP ;Release extended memory block. Error code returned in DX:AX. Arguments are: ;HANDLE:DWORD = Handle to previously allocated block XFREE PROC FAR, ARG HANDLE:DWORD ;Handle to previously allocated block MOV EAX,HANDLE CALL FREEMEM PUSH EAX ;Put error code in DX:AX POP AX POP DX RET XFREE ENDP ;Map physical memory to logical address space. Error code returned in DX:AX. ;Arguments are: ;PHYSADR:DWORD = Linear address of physical memory ;BLKSIZE:DWORD = Size of memory block (in bytes) ;LOGADRPTR:DWORD = Far pointer to DWORD to receive logical address MAPIOMEM PROC FAR, ARG PHYSADR:DWORD,BLKSIZE:DWORD,LOGADRPTR:DWORD PUSH BX PUSH DS MOV EDX,PHYSADR MOV EAX,BLKSIZE PUSHD OFFSET PMMAPIO CALL CALLPM LDS BX,LOGADRPTR MOV [BX],EDX PUSH EAX ;Place error code in DX:AX POP AX POP DX POP DS POP BX RET MAPIOMEM ENDP ;Move memory. This routine is suitable for interrupt handlers. It uses a ;stack in DSEG rather than TSEG. Arguments are: ;DESTADR:DWORD = Destination address. ;SOURCEADR:DWORD = Source address. ;NOBYTES:DWORD = Number of bytes to transfer. ALIGN 16 MOVMEM PROC FAR, ARG DESTADR:DWORD,SOURCEADR:DWORD,NOBYTES:DWORD PUSHAD PUSH DS PUSH ES PUSH FS PUSH GS MOV AX,DSEG MOV DS,AX MOV ESI,SOURCEADR ;Load registers as required by MOVMEM32 MOV EDI,DESTADR MOV ECX,NOBYTES MOV EDX,ISTKPTR ;Get currently available pointer for the dynamic stack SUB ISTKPTR,STKALLOC ;Prepare dynamic stack for possibility of interrupt call back to this routine MOV BX,SP ;Save the old stack in EBX PUSH SS PUSH BX POP EBX MOV SS,AX ;Load the dynamic stack MOV ESP,EDX CALL SWITCHPM ;Switch to 16-bit protected mode PUSHW 0H ;PUSH 32-bit far return address back to this procedure MOV AX,CSEGSEL PUSH AX PUSHD OFFSET RETADR PUSHW 0H ;PUSH 32-bit far address of MOVMEM32 MOV AX,TSEGSEL PUSH AX PUSHD OFFSET MOVMEM32 MOV DS,FLATDSEL ;Switch to flat data model DB 66H ;Execute 32-bit RETF RETF RETADR: CALL SWITCHRM ;Switch back to real mode PUSH EBX ;Load calling stack LSS SP,[ESP] ADD ISTKPTR,STKALLOC ;Adjust dynamic stack pointer POP GS POP FS POP ES POP DS POPAD RET MOVMEM ENDP ;Calculate linear address from segment address. Call with segment address on ;stack. Linear address returned in DX:AX. LINADR PROC FAR, ARG SEGADDRESS:DWORD ;Segment address of variable MOV AX,WORD PTR SEGADDRESS[2] ;Do not corrupt high words (might be used in 16-bit interrupt handler) XOR DX,DX SHLD DX,AX,4 SHL AX,4 ADD AX,WORD PTR SEGADDRESS[0] ADC DX,0 RET LINADR ENDP ;++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ;Interfaces to XLIB file management routines. Each of these procedures should ;be called with the segment address of the control block on the stack. These ;routines cannot be called during interrupts since each routine calls DOS. ;++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ;Create file. XFCREATE PROC FAR PUSHD OFFSET PMXCREATE JMP CHAINTOPM XFCREATE ENDP ;Open file. XFOPEN PROC FAR PUSHD OFFSET PMXOPEN JMP CHAINTOPM XFOPEN ENDP ;Close file. XFCLOSE PROC FAR PUSHD OFFSET PMXCLOSE JMP CHAINTOPM XFCLOSE ENDP ;Load file XFLOAD PROC FAR PUSHD OFFSET PMXLOAD JMP CHAINTOPM XFLOAD ENDP ;Save file. XFSAVE PROC FAR PUSHD OFFSET PMXSAVE JMP CHAINTOPM XFSAVE ENDP ;Random read file. XFREAD PROC FAR PUSHD OFFSET PMXREAD JMP CHAINTOPM XFREAD ENDP ;Random write file. XFWRITE PROC FAR PUSHD OFFSET PMXWRITE JMP CHAINTOPM XFWRITE ENDP ;Transfer control to protected mode after converting segment address of control ;block to linear address in EAX. CHAINTOPM PROC FAR PUSH DWORD PTR [ESP+8] ;PUSH segment address of control block CALL LINADR PUSH DX PUSH AX POP EAX CALL CALLPM RET 4 CHAINTOPM ENDP PUBLIC PASCAL XMALLOC PUBLIC PASCAL XFREE PUBLIC PASCAL MAPIOMEM PUBLIC PASCAL LINADR PUBLIC PASCAL MOVMEM PUBLIC PASCAL XFCREATE PUBLIC PASCAL XFOPEN PUBLIC PASCAL XFCLOSE PUBLIC PASCAL XFLOAD PUBLIC PASCAL XFSAVE PUBLIC PASCAL XFREAD PUBLIC PASCAL XFWRITE CSEG ENDS TSEG SEGMENT PARA PUBLIC USE32 'CODE' ASSUME CS:TSEG IF TASMMODE LARGESTACK ENDIF ;Transfer memory. Call with source address in ESI, destination address in EDI, ;and number of bytes to transfer in ECX. Does not preserve registers. This ;routine is far and is therefore a departure from XLIB policy. This approach ;is used because the routine is not entered with the standard XLIB mode switch ;procedures, CALLPM and ENTERPM. Standard mode switch procedures are not used ;because they are not reentrant and therefore cannot be used in interrupt ;handlers. ALIGN 16 MOVMEM32 PROC FAR CMP EDI,ESI JBE ENTERDN4 JMP ENTERUP4 ALIGN 4 UP4LOOP: MOV EAX,[ESI+1*ECX] ;Destination address is higher than source address MOV [EDI+1*ECX],EAX ENTERUP4: SUB ECX,4 JAE UP4LOOP ADD ECX,4 JNZ ENTERUP1 RET ALIGN 4 UP1LOOP: MOV AL,[ESI+1*ECX] MOV [EDI+1*ECX],AL ENTERUP1: DEC ECX JNS UP1LOOP RET ALIGN 4 DN4LOOP: MOV EAX,[ESI] ;Destination address is lower than source address MOV [EDI],EAX ADD ESI,4 ADD EDI,4 ENTERDN4: SUB ECX,4 JAE DN4LOOP ADD ECX,4 JNZ ENTERDN1 RET ALIGN 4 DN1LOOP: MOV AL,[ESI] MOV [EDI],AL INC ESI INC EDI ENTERDN1: DEC ECX JNS DN1LOOP RET MOVMEM32 ENDP TSEG ENDS END