; ********************************************************************** ; Copyright (C) 1995 by Holger Veit (Holger.Veit@gmd.de) ; Use at your own risk! No Warranty! The author is not responsible for ; any damage or loss of data caused by proper or improper use of this ; device driver. ; ********************************************************************** ; ; compile with ALP ; TITLE ICCIO.ASM .386 .387 CODE32 SEGMENT DWORD USE32 PUBLIC 'CODE' CODE32 ENDS DATA32 SEGMENT DWORD USE32 PUBLIC 'DATA' DATA32 ENDS CONST32 SEGMENT DWORD USE32 PUBLIC 'CONST' CONST32 ENDS BSS32 SEGMENT DWORD USE32 PUBLIC 'BSS' BSS32 ENDS DGROUP GROUP CONST32, BSS32, DATA32 ASSUME CS:FLAT, DS:FLAT, SS:FLAT, ES:FLAT DATA32 SEGMENT DATA32 ENDS BSS32 SEGMENT BSS32 ENDS CONST32 SEGMENT CONST32 ENDS DATA32 SEGMENT ioentry DWORD 0 gdt WORD 0 DATA32 ENDS CODE32 SEGMENT ; performs fast output of a byte to an I/O port ; this routine is intended to be called from gcc C code ; ; Calling convention: ; void c_outb1(short port,char data) ; ; PUBLIC c_outb1 ALIGN 04H c_outb1 PROC MOV EDX, [ESP+4] ; get port MOV AL, [ESP+8] ; get data OUT DX,AL RET c_outb1 ENDP ; performs fast output of a word to an I/O port ; this routine is intended to be called from gcc C code ; ; Calling convention: ; void c_outw1(short port,short data) ; ; PUBLIC c_outw1 ALIGN 04H c_outw1 PROC MOV EDX, [ESP+4] ; get port MOV AX, [ESP+8] ; get data OUT DX,AX RET c_outw1 ENDP ; performs fast output of a longword to an I/O port ; this routine is intended to be called from gcc C code ; ; Calling convention: ; void c_outl1(short port,long data) ; ; PUBLIC c_outl1 ALIGN 04H c_outl1 PROC MOV EDX, [ESP+4] ; get port MOV EAX, [ESP+8] ; get data OUT DX, EAX RET c_outl1 ENDP ; performs fast input of a byte from an I/O port ; this routine is intended to be called from gcc C code ; ; Calling convention: ; char c_inb1(short port) ; ; PUBLIC c_inb1 ALIGN 04H c_inb1 PROC MOV EDX, [ESP+4] ; get port IN AL,DX AND EAX, 000000FFh RET c_inb1 ENDP ; performs fast input of a word from an I/O port ; this routine is intended to be called from gcc C code ; ; Calling convention: ; short c_inw1(short port) ; ; PUBLIC c_inw1 ALIGN 04H c_inw1 PROC MOV EDX, [ESP+4] ; get port IN AX, DX AND EAX, 0000FFFFh ; mask out word RET c_inw1 ENDP ; performs fast input of a longword from an I/O port ; this routine is intended to be called from gcc C code ; ; Calling convention: ; lomg c_inl1(short port) ; ; PUBLIC c_inl1 ALIGN 04H c_inl1 PROC MOV EDX, [ESP+4] ; get port IN EAX, DX RET c_inl1 ENDP CODE32 ENDS ;------------------------------------------------------------------------------ ; Initialize I/O access via the driver. ; You *must* call this routine once for each *thread* that wants to do ; I/O. ; ; The routine is mainly equivalent to a C routine performing the ; following (but no need to add another file): ; DosOpen("/dev/fastio$", read, nonexclusive) ; DosDevIOCtl(device, XFREE86IO, IOGETSEL32) ; selector -> ioentry+4 ; DosClose(device) ; ; Calling convention: ; int io_init1(void) ; Return: ; 0 if successful ; standard APIRET RETurn code if error ; CONST32 SEGMENT ALIGN 04H devname: DB "/dev/fastio$",0 CONST32 ENDS CODE32 SEGMENT PUBLIC io_init1 EXTRN DosOpen:PROC EXTRN DosClose:PROC EXTRN DosDevIOCtl:PROC ALIGN 04H io_init1 PROC PUSH EBP MOV EBP, ESP ; standard stack frame SUB ESP, 16 ; reserve memory ; -16 = len arg of DosDevIOCtl ; -12 = action arg of DosOpen ; -8 = fd arg of DosOpen ; -2 = short GDT selector arg PUSH 0 ; (PEAOP2)NULL PUSH 66 ; OPENACCESSREADWRITE|OPENSHAREDENYNONE PUSH 1 ; FILEOPEN PUSH 0 ; FILENORMAL PUSH 0 ; initial size LEA EAX, [EBP-12] ; Adress of 'action' arg PUSH EAX LEA EAX, [EBP-8] ; Address of 'fd' arg PUSH EAX PUSH OFFSET FLAT:devname CALL DosOpen ; call DosOpen ADD ESP, 32 ; cleanup stack frame CMP EAX, 0 ; is return code zero? JE goon ; yes, proceed LEAVE ; no RETurn error RET ALIGN 04H goon: LEA EAX, [EBP-16] ; address of 'len' arg of DosDevIOCtl PUSH EAX PUSH 2 ; sizeof(short) LEA EAX, [EBP-2] ; address to return the GDT selector PUSH EAX PUSH 0 ; no parameter len PUSH 0 ; no parameter size PUSH 0 ; no parameter address PUSH 100 ; function code IOGETSEL32 PUSH 118 ; category code XFREE6IO MOV EAX,[EBP-8] ; file handle PUSH EAX CALL DosDevIOCtl ; perform ioctl ADD ESP, 36 ; cleanup stack CMP EAX, 0 ; is return code = 0? JE ok ; yes, proceed PUSH EAX ; was error, save error code MOV EAX, [EBP-8] ; file handle PUSH EAX CALL DosClose ; close device ADD ESP,4 ; clean stack POP EAX ; get error code LEAVE ; return error RET ALIGN 04H ok: MOV EAX, [EBP-8] ; file handle PUSH EAX ; do normal close CALL DosClose ADD ESP,4 ; clean stack MOV AX, [EBP-2] ; load gdt selector MOV gdt, AX ; store in ioentry address selector part XOR EAX, EAX ; EAX = 0 MOV DWORD PTR [ioentry], EAX ; clear ioentry offset part ; return code = 0 (in EAX) ; now use this function to raise the IOPL PUSH EBX ; bird fix MOV EBX,13 ; special function code CALL FWORD PTR [ioentry] ; CALL intersegment indirect 16:32 POP EBX ; bird fix ; thread should now be running at IOPL=3 XOR EAX, EAX ; return code = 0 LEAVE ; clean stack frame RET ; exit io_init1 ENDP ; void in_init(short) PUBLIC io_init2 ALIGN 04H io_init2 PROC MOV EAX, dword ptr [ESP+4] MOV gdt, AX ; store in ioentry address selector part XOR EAX, EAX ; EAX = 0 MOV DWORD PTR [ioentry], EAX ; clear ioentry offset part ; return code = 0 (in EAX) ; now use this function to raise the IOPL PUSH EBX ; bird fix MOV EBX,13 ; special function code CALL FWORD PTR [ioentry] ; CALL intersegment indirect 16:32 POP EBX ; bird fix XOR EAX, EAX ; return code = 0 ret io_init2 ENDP PUBLIC io_exit1 ALIGN 04H io_exit1 PROC push EBP MOV EBP, ESP ; stackframe, I am accustomed to this :-) MOV AX, gdt ; check if ioinit was called once OR AX, AX JZ exerr ; no gdt entry, so process cannot be at IOPL=3 ; through this mechanism PUSH EBX ; bird fix MOV EBX, 14 ; function code to disable iopl CALL FWORD PTR [ioentry] ; call intersegment indirect 16:32 POP EBX ; bird fix ; process should now be at IOPL=3 again XOR EAX, EAX ; ok, RETurn code = 0 LEAVE RET exerr: XOR EAX, EAX ; not ok, RETurn code = ffffffff DEC EAX LEAVE RET io_exit1 ENDP ; for diagnostic only ;; PUBLIC psw ;; ALIGN 04H ;;psw PROC ;; PUSHF ; get the current PSW ;; POP EAX ; into EAX ;; RET ;;psw ENDP CODE32 ENDS END