_pm.asm

BIOS emulator and interface to Realmode X86 Emulator Library Can emulate a PCI Graphic Controller V

;****************************************************************************
;*
;*					SciTech OS Portability Manager Library
;*
;*  ========================================================================
;*
;*    The contents of this file are subject to the SciTech MGL Public
;*    License Version 1.0 (the "License"); you may not use this file
;*    except in compliance with the License. You may obtain a copy of
;*    the License at http://www.scitechsoft.com/mgl-license.txt
;*
;*    Software distributed under the License is distributed on an
;*    "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
;*    implied. See the License for the specific language governing
;*    rights and limitations under the License.
;*
;*    The Original Code is Copyright (C) 1991-1998 SciTech Software, Inc.
;*
;*    The Initial Developer of the Original Code is SciTech Software, Inc.
;*    All Rights Reserved.
;*
;*  ========================================================================
;*
;* Language:	80386 Assembler, TASM 4.0 or NASM
;* Environment:	32-bit Windows VxD
;*
;* Description:	Low level assembly support for the PM library specific to
;*				Windows VxDs.
;*
;****************************************************************************

		IDEAL

include	"scitech.mac"				; Memory model macros

header    	_pm             		; Set up memory model

begdataseg	_pm

	cextern	_PM_savedDS,USHORT

enddataseg	_pm

begcodeseg  _pm					; Start of code segment

;----------------------------------------------------------------------------
; void PM_segread(PMSREGS *sregs)
;----------------------------------------------------------------------------
; Read the current value of all segment registers
;----------------------------------------------------------------------------
cprocstart	PM_segread

		ARG		sregs:DPTR

		enter_c

		mov		ax,es
		_les	_si,[sregs]
		mov		[_ES _si],ax
		mov		[_ES _si+2],cs
		mov		[_ES _si+4],ss
		mov		[_ES _si+6],ds
		mov		[_ES _si+8],fs
		mov		[_ES _si+10],gs

		leave_c
		ret

cprocend

;----------------------------------------------------------------------------
; int PM_int386x(int intno, PMREGS *in, PMREGS *out,PMSREGS *sregs)
;----------------------------------------------------------------------------
; Issues a software interrupt in protected mode. This routine has been
; written to allow user programs to load CS and DS with different values
; other than the default.
;----------------------------------------------------------------------------
cprocstart	PM_int386x

; Not used for VxDs

		ret

cprocend

;----------------------------------------------------------------------------
; void PM_saveDS(void)
;----------------------------------------------------------------------------
; Save the value of DS into a section of the code segment, so that we can
; quickly load this value at a later date in the PM_loadDS() routine from
; inside interrupt handlers etc. The method to do this is different
; depending on the DOS extender being used.
;----------------------------------------------------------------------------
cprocstart	PM_saveDS

		mov		[_PM_savedDS],ds	; Store away in data segment
		ret

cprocend

;----------------------------------------------------------------------------
; void PM_loadDS(void)
;----------------------------------------------------------------------------
; Routine to load the DS register with the default value for the current
; DOS extender. Only the DS register is loaded, not the ES register, so
; if you wish to call C code, you will need to also load the ES register
; in 32 bit protected mode.
;----------------------------------------------------------------------------
cprocstart	PM_loadDS

		mov		ds,[cs:_PM_savedDS]	; We can access the proper DS through CS
		ret

cprocend

;----------------------------------------------------------------------------
; void PM_setBankA(int bank)
;----------------------------------------------------------------------------
cprocstart		PM_setBankA

; Not used for VxDs

		ret

cprocend

;----------------------------------------------------------------------------
; void PM_setBankAB(int bank)
;----------------------------------------------------------------------------
cprocstart		PM_setBankAB

; Not used for VxDs

		ret

cprocend

;----------------------------------------------------------------------------
; void PM_setCRTStart(int x,int y,int waitVRT)
;----------------------------------------------------------------------------
cprocstart		PM_setCRTStart

; Not used for VxDs

		ret

cprocend

; Macro to delay briefly to ensure that enough time has elapsed between
; successive I/O accesses so that the device being accessed can respond
; to both accesses even on a very fast PC.

ifdef	USE_NASM
%macro	DELAY 0
		jmp		short $+2
		jmp		short $+2
		jmp		short $+2
%endmacro
%macro	IODELAYN 1
%rep	%1
		DELAY
%endrep
%endmacro
else
macro	DELAY
		jmp		short $+2
		jmp		short $+2
		jmp		short $+2
endm
macro	IODELAYN	N
	rept	N
		DELAY
	endm
endm
endif

;----------------------------------------------------------------------------
; uchar _PM_readCMOS(int index)
;----------------------------------------------------------------------------
; Read the value of a specific CMOS register. We do this with both
; normal interrupts and NMI disabled.
;----------------------------------------------------------------------------
cprocstart	_PM_readCMOS

		ARG		index:UINT

		push	_bp
		mov		_bp,_sp
		pushfd
		mov		al,[BYTE index]
		or		al,80h				; Add disable NMI flag
		cli
		out		70h,al
		IODELAYN 5
		in		al,71h
		mov		ah,al
		xor		al,al
		IODELAYN 5
		out		70h,al				; Re-enable NMI
		sti
		mov		al,ah				; Return value in AL
		popfd
		pop		_bp
		ret

cprocend

;----------------------------------------------------------------------------
; void _PM_writeCMOS(int index,uchar value)
;----------------------------------------------------------------------------
; Read the value of a specific CMOS register. We do this with both
; normal interrupts and NMI disabled.
;----------------------------------------------------------------------------
cprocstart	_PM_writeCMOS

		ARG		index:UINT, value:UCHAR

		push	_bp
		mov		_bp,_sp
		pushfd
		mov		al,[BYTE index]
		or		al,80h				; Add disable NMI flag
		cli
		out		70h,al
		IODELAYN 5
		mov		al,[value]
		out		71h,al
		xor		al,al
		IODELAYN 5
		out		70h,al				; Re-enable NMI
		sti
		popfd
		pop		_bp
		ret

cprocend

;----------------------------------------------------------------------------
; double _ftol(double f)
;----------------------------------------------------------------------------
; Calls to __ftol are generated by the Borland C++ compiler for code
; that needs to convert a floating point type to an integral type.
;
; Input: floating point number on the top of the '87.
;
; Output: a (signed or unsigned) long in EAX
; All other registers preserved.
;-----------------------------------------------------------------------
cprocstart	_ftol

		LOCAL   temp1:WORD, temp2:QWORD = LocalSize

		push    ebp
		mov     ebp,esp
		sub		esp,LocalSize

		fstcw   [temp1]	      			; save the control word
		fwait
		mov     al,[BYTE temp1+1]
		or      [BYTE temp1+1],0Ch    	; set rounding control to chop
		fldcw   [temp1]
		fistp   [temp2]         		; convert to 64-bit integer
		mov     [BYTE temp1+1],al
		fldcw   [temp1]					; restore the control word
		mov     eax,[DWORD temp2]       ; return LS 32 bits
		mov     edx,[DWORD temp2+4]	 	;        MS 32 bits

		mov     esp,ebp
		pop     ebp
		ret

cprocend

endcodeseg  _pm

		END						; End of module