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|
;****************************************************************************
;*
;* 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 SMX embedded systems development
;*
;* Description: Low level assembly support for the PM library specific to
;* SMX.
;*
;****************************************************************************
IDEAL
include "scitech.mac" ; Memory model macros
header _pm ; Set up memory model
begdataseg _pm
cextern _PM_savedDS,USHORT
intel_id db "GenuineIntel" ; Intel vendor ID
enddataseg _pm
begcodeseg _pm ; Start of code segment
;----------------------------------------------------------------------------
; void PM_segread(PMSREGS *sregs)
;----------------------------------------------------------------------------
; Read the current value of all segment registers
;----------------------------------------------------------------------------
cprocstartdll16 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
; Create a table of the 256 different interrupt calls that we can jump
; into
ifdef USE_NASM
%assign intno 0
intTable:
%rep 256
db 0CDh
db intno
%assign intno intno + 1
ret
nop
%endrep
else
intno = 0
intTable:
REPT 256
db 0CDh
db intno
intno = intno + 1
ret
nop
ENDM
endif
;----------------------------------------------------------------------------
; _PM_genInt - Generate the appropriate interrupt
;----------------------------------------------------------------------------
cprocnear _PM_genInt
push _ax ; Save _ax
push _bx ; Save _bx
mov ebx,[UINT esp+12] ; EBX := interrupt number
mov _ax,offset intTable ; Point to interrupt generation table
shl _bx,2 ; _BX := index into table
add _ax,_bx ; _AX := pointer to interrupt code
xchg eax,[esp+4] ; Restore eax, and set for int
pop _bx ; restore _bx
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.
;----------------------------------------------------------------------------
cprocstartdll16 PM_int386x
ARG intno:UINT, inptr:DPTR, outptr:DPTR, sregs:DPTR
LOCAL flags:UINT, sv_ds:UINT, sv_esi:ULONG = LocalSize
enter_c
push ds
push es ; Save segment registers
push fs
push gs
_lds _si,[sregs] ; DS:_SI -> Load segment registers
mov es,[_si]
mov bx,[_si+6]
mov [sv_ds],_bx ; Save value of user DS on stack
mov fs,[_si+8]
mov gs,[_si+10]
_lds _si,[inptr] ; Load CPU registers
mov eax,[_si]
mov ebx,[_si+4]
mov ecx,[_si+8]
mov edx,[_si+12]
mov edi,[_si+20]
mov esi,[_si+16]
push ds ; Save value of DS
push _bp ; Some interrupts trash this!
clc ; Generate the interrupt
push [UINT intno]
mov ds,[WORD sv_ds] ; Set value of user's DS selector
call _PM_genInt
pop _bp ; Pop intno from stack (flags unchanged)
pop _bp ; Restore value of stack frame pointer
pop ds ; Restore value of DS
pushf ; Save flags for later
pop [UINT flags]
push esi ; Save ESI for later
pop [DWORD sv_esi]
push ds ; Save DS for later
pop [UINT sv_ds]
_lds _si,[outptr] ; Save CPU registers
mov [_si],eax
mov [_si+4],ebx
mov [_si+8],ecx
mov [_si+12],edx
push [DWORD sv_esi]
pop [DWORD _si+16]
mov [_si+20],edi
mov _bx,[flags] ; Return flags
and ebx,1h ; Isolate carry flag
mov [_si+24],ebx ; Save carry flag status
_lds _si,[sregs] ; Save segment registers
mov [_si],es
mov _bx,[sv_ds]
mov [_si+6],bx ; Get returned DS from stack
mov [_si+8],fs
mov [_si+10],gs
pop gs ; Restore segment registers
pop fs
pop es
pop ds
leave_c
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.
;----------------------------------------------------------------------------
cprocstartdll16 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.
;----------------------------------------------------------------------------
cprocstartdll16 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
ARG bank:UINT
push ebp
mov ebp,esp
push ebx
mov _bx,0
mov _ax,4F05h
mov _dx,[bank]
int 10h
pop ebx
pop ebp
ret
cprocend
;----------------------------------------------------------------------------
; void PM_setBankAB(int bank)
;----------------------------------------------------------------------------
cprocstart PM_setBankAB
ARG bank:UINT
push ebp
mov ebp,esp
push ebx
mov _bx,0
mov _ax,4F05h
mov _dx,[bank]
int 10h
mov _bx,1
mov _ax,4F05h
mov _dx,[bank]
int 10h
pop ebx
pop ebp
ret
cprocend
;----------------------------------------------------------------------------
; void PM_setCRTStart(int x,int y,int waitVRT)
;----------------------------------------------------------------------------
cprocstart PM_setCRTStart
ARG x:UINT, y:UINT, waitVRT:UINT
push ebp
mov ebp,esp
push ebx
mov _bx,[waitVRT]
mov _cx,[x]
mov _dx,[y]
mov _ax,4F07h
int 10h
pop ebx
pop ebp
ret
cprocend
;----------------------------------------------------------------------------
; int _PM_inp(int port)
;----------------------------------------------------------------------------
; Reads a byte from the specified port
;----------------------------------------------------------------------------
cprocstart _PM_inp
ARG port:UINT
push _bp
mov _bp,_sp
xor _ax,_ax
mov _dx,[port]
in al,dx
pop _bp
ret
cprocend
;----------------------------------------------------------------------------
; void _PM_outp(int port,int value)
;----------------------------------------------------------------------------
; Write a byte to the specified port.
;----------------------------------------------------------------------------
cprocstart _PM_outp
ARG port:UINT, value:UINT
push _bp
mov _bp,_sp
mov _dx,[port]
mov _ax,[value]
out dx,al
pop _bp
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
;----------------------------------------------------------------------------
; _PM_getPDB - Return the Page Table Directory Base address
;----------------------------------------------------------------------------
cprocstart _PM_getPDB
mov eax,cr3
and eax,0FFFFF000h
ret
cprocend
;----------------------------------------------------------------------------
; _PM_flushTLB - Flush the Translation Lookaside buffer
;----------------------------------------------------------------------------
cprocstart PM_flushTLB
wbinvd ; Flush the CPU cache
mov eax,cr3
mov cr3,eax ; Flush the TLB
ret
cprocend
endcodeseg _pm
END ; End of module
|
