;
;
;       Copyright (C) Microsoft Corporation, 1987-89
;
;       This Module contains Proprietary Information of Microsoft
;       Corporation and should be treated as Confidential.
;
title   emoem.asm - OEM dependent code for 8087

;--------------------------------------------------------------------
;
;       OEM customization routines for 8087/80287 coprocessor
;
;       This module is designed to work with the following
;       Microsoft language releases:
;
;               Microsoft C 3.00 and later
;               Microsoft FORTRAN 77 3.30 and later
;               Microsoft Pascal 3.30 and later
;
;       This module supersedes the OEMR7.ASM module used in earlier
;       versions of Microsoft FORTRAN 77 and Pascal.  The documentation
;       provided with the FORTRAN and Pascal releases refers to the old
;       OEMR7.ASM module and is only slightly relevant to this module.
;
;       The following routines need to be written to properly handle the
;       8087/808287 installation, termination, and interrupt handler
;
;       __FPINSTALL87           install 8087 interrupt handler
;       __FPTERMINATE87         deinstall 8087 interrupt handler
;       __fpintreset            reset OEM hardware if an 8087 interrupt
;
;       *****  NEW INSTRUCTIONS  *****
;
;       If you want a PC clone version, do nothing.  The libraries are
;       setup for working on IBM PC's and clones.
;
;       These instructions only need to be followed if a non-IBM PC
;       clone version is desired.
;
;       This module should be assembled with the
;       Microsoft Macro Assembler Version 4.00 or later as follows:
;
;               masm -DOEM -r emoem.asm;
;
;       Most hardware handles the 8087/80287 in one of the following
;       three ways -
;
;       1.      NMI - IBM PC and clones all handle the interrupt this way
;       2.      single 8259
;       3.      master/slave 8259
;
;       Manufacturer specific initialization is supported for these 3
;       machine configurations either by modifying this file and replacing
;       the existing EMOEM module in the math libraries or by patching
;       the .LIB and .EXE files directly.
;
;               LIB 87-+EMOEM;
;               LIB EM-+EMOEM;
;
;--------------------------------------------------------------------

ifdef   OEM
if1
	%out    OEM version for non-clone support
endif
endif

;---------------------------------------------------------------------
;       Assembly constants.
;---------------------------------------------------------------------

NULL_JMP    macro
	jmp     $+2
	endm

WASTE_TIME  macro   count
	local   WasteLoop

	push    cx
ifnb  <count>
	mov     cx, count
else
	mov     cx, 10h
endif
WasteLoop:
	push    ax
	pop     ax

	loop    WasteLoop
	pop     cx

	endm


; MS-DOS OS calls

   OPSYS        EQU     21H
   SETVECOP     EQU     25H
   GETVECOP     EQU     35H
   DOSVERSION   EQU     30h
ifndef  _NOCTRLC
   CTLCVEC      EQU     23h
endif   ;_NOCTRLC

extrn __WINFLAGS:abs
WF_PMODE    equ     1
WF_CPU286   equ     2
WF_CPU386   equ     4
WF_WIN286   equ     10h
WF_WIN386   equ     20h

EMULATOR_DATA   segment para public 'FAR_DATA'
assume  ds:EMULATOR_DATA

;       User may place data here if DS is setup properly.
;       Recommend keeping the data items in the code segment.


ifdef  OEM
extrn  aoldIMR:byte             ; 1st 8259 original IMR value
extrn  boldIMR:byte             ; 2nd 8259 original IMR value
endif   ;OEM


extrn  OldNMIVec:dword          ; Old value in 8087 exception interrupt vector

ifndef  _NOCTRLC
extrn  ctlc:dword               ; Old value of Control-C vector (INT 23h)
endif   ;_NOCTRLC


EMULATOR_DATA   ends



EMULATOR_TEXT   segment para public 'CODE'
assume  cs:EMULATOR_TEXT

	public  __FPINSTALL87           ; DO NOT CHANGE THE CASE ON
	public  __FPTERMINATE87         ; THESE PUBLIC DEFINITIONS

	extrn   __FPEXCEPTION87:near    ; DO NOT CHANGE CASE
	extrn   __FPEXCEPTION87P:near


ifdef   _NO87INSTALL    ; install/terminate routines for NO87 case for QuickC

	public  __FPINSTALLNO87 
	public  __FPTERMINATENO87

endif   ;_NO87INSTALL


ifdef   OEM

;***********************************************************************
;
; Hardware dependent parameters in the 8087 exception handler.
;
; For machines using 2 8259's to handle the 8087 exception, be sure that
; the slave 8259 is the 1st below and the master is the 2nd.
;
; The last 4 fields allow you to enable extra interrupt lines into the
; 8259s.  It should only be necessary to use these fields if the 8087
; interrupt is being masked out by the 8259 PIC.
;
; The ocw2's (EOI commands) can be either non-specific (20H) or
; specific (6xH where x=0 to 7).  If you do not know which interrupt
; request line on the 8259 the 8087 exception uses, then you should issue
; the non-specific EOI (20H).  Interrupts are off at this point in the
; interrupt handler so a higher priority interrupt will not be seen.

oeminfo struc
oemnum  db      0               ; MS-DOS OEM number (IBM is 00h)
intnum  db      2               ; IBM PC clone interrupt number
share   db      0               ; nonzero if original vector should be taken
a8259   dw      0               ; 1st 8259 (A0=0) port #
aocw2   db      0               ; 1st 8259 (A0=0) EOI command
b8259   dw      0               ; 2nd 8259 (A0=0) port #
bocw2   db      0               ; 2nd 8259 (A0=0) EOI command
a8259m  dw      0               ; 1st 8259 (A0=1) port #
aocw1m  db      0               ; 1st 8259 (A0=1) value to mask against IMR
b8259m  dw      0               ; 2nd 8259 (A0=1) port #
bocw1m  db      0               ; 2nd 8259 (A0=1) value to mask against IMR
oeminfo ends

;-----------------------------------------------------------------------
;       OEM specific 8087 information
;
;       If the OEM number returned from the DOS version call matches,
;       this information is automatically moved into the oem struc below.

oemtab  label   byte    ; Table of OEM specific values for 8087

;               OEM#, int, shr, a59, acw2,b59, bcw2,a59m,acw1,b59m,bcw1

;TI Professional Computer
TI_prof oeminfo <028h,047h,000h,018h,020h,0000,0000,0000,0000,0000,0000>

	db      0       ; end of table

;       Unique pattern that can be searched for with the debugger so that
;       .LIB or .EXE files can be patched with the correct values.
;       If new values are patched into .LIB or .EXE files, care must be
;       taken in insure the values are correct.  In particular, words and
;       bytes are intermixed in oeminfo structure.  Remember words are
;       stored low byte - high byte in memory on the 8086 family.

	db      '<<8087>>'      ; older versions used '<8087>'

;       Some manufacturer's machines can not be differentiated by the
;       OEM number returned by the MS-DOS version check system call.
;       For these machines it is necessary to replace the line below

oem1    oeminfo <>              ; default values for IBM PC & clones

;       with one of the following.  If your machine has an 8087 capability
;       and it is not in the list below, you should contact your hardware
;       manufacturer for the necessary information.

;ACT Apricot
;oem1    oeminfo <000h,055h,000h,000h,020h,000h,000h,000h,000h,000h,000h>

;NEC APC3 and PC-9801  (OEM number returned by NEC MS-DOS's is different)
;oem1    oeminfo <000h,016h,000h,008h,066h,000h,067h,00Ah,0BFh,002h,07Fh>

;---------------------------------------------------------------------

endif   ;OEM


page

;---------------------------------------------------------------------
;
;       Perform OEM specific initialization of the 8087.
;

__FPINSTALL87:
	push    ds                      ; DS = EMULATOR_DATA


ifdef   OEM
	push    ds
	pop     es                      ; CS = DS = ES
	mov     ah,DOSVERSION
	int     OPSYS                   ; bh = OEM#
	cld
	mov     si,offset oemtab        ; start of OEM 8087 info table
	mov     di,offset oem1+1
	mov     cx,(size oem1)-1
OEMloop:
	lodsb                           ; get OEM#
	or      al,al
	jz      OEMdone                 ; OEM# = 0 - did not find OEM
	cmp     al,bh                   ; correct OEM#
	je      OEMfound
	add     si,cx                   ; skip over OEM information
	jmp     OEMloop

OEMfound:
	rep     movsb                   ; move the information

OEMdone:                                ; done with automatic customization
endif   ;OEM

; Save old interrupt vector.
; Ask operating system for vector.

ifdef  WINDOWS
	mov     ax, word ptr [OldNMIVec]
	or      ax, word ptr [OldNMIVec+2]
	jnz     SetVector
endif   ;WINDOWS

ifdef   OEM
	mov     al,[oem1].intnum        ; Interrupt vector number.
	mov     ah,GETVECOP             ; Operating system call interrupt.
else
	mov     ax,GETVECOP shl 8 + 2   ; get interrupt vector 2
endif   ;OEM
	int     OPSYS                   ; Call operating system.

	mov     word ptr [OldNMIVec],bx ; Squirrel away old vector.
	mov     word ptr [OldNMIVec+2],es

; Have operating system install interrupt vectors.

SetVector:
	push    cs                      ; Move current CS to DS for opsys calls.
	pop     ds
assume  ds:EMULATOR_TEXT

	mov     dx,offset __fpinterrupt87 ; Load DX with 8087 interrupt handler.
ifdef   OEM
	mov     ah,SETVECOP             ; Set interrupt vector code in AH.
	mov     al,[oem1].intnum        ; Set vector number.
else
	mov     ax,SETVECOP shl 8 + 2   ; set interrupt vector 2
endif   ;OEM
	int     OPSYS                   ; Install vector.

	mov     ax, __WINFLAGS
	test    ax, WF_PMODE
	jz      SkipSettingIRQ13

	.286p
	.287
	fsetpm                          ; set PM just in case Windows didn't.
	.8086
	.8087

	push    cs
	pop     ds                       ; Move current CS to DS for opsys calls.
assume  ds:EMULATOR_TEXT
	mov     dx, offset __fpIRQ13     ; Load DX with IRQ 13 interrupt handler.
	mov     ax, SETVECOP shl 8 + 75h ; set interrupt vector 75h
	int     OPSYS                    ; Install vector.
SkipSettingIRQ13:

ifndef  _NOCTRLC
; Intercept Control-C vector to guarentee cleanup

	mov     ax,GETVECOP shl 8 + CTLCVEC
	int     OPSYS
	mov     word ptr [ctlc],bx
	mov     word ptr [ctlc+2],es
	mov     dx,offset ctlcexit
	mov     ax,SETVECOP shl 8 + CTLCVEC
	int     OPSYS
endif   ;_NOCTRLC

ifdef   OEM

;       set up 8259's so that 8087 interrupts are enabled

	mov     ah,[oem1].aocw1m        ; get mask for 1st 8259 IMR
	or      ah,ah                   ;   if 0, don't need to do this
	jz      installdone             ;   and only 1 8259
	mov     dx,[oem1].a8259m        ; get port number for 1st 8259 (A0=1)
	in      al,dx                   ; read old IMR value
	mov     [aoldIMR],al            ; save it to restore at termination
	and     al,ah                   ; mask to enable interrupt
	jmp     short $+2               ; for 286's
	out     dx,al                   ; write out new mask value

	mov     ah,[oem1].bocw1m        ; get mask for 2nd 8259 IMR
	or      ah,ah                   ;   if 0, don't need to do this
	jz      installdone             ;
	mov     dx,[oem1].b8259m        ; get port number for 2nd 8259 (A0=1)
	in      al,dx                   ; read old IMR value
	mov     [boldIMR],al            ; save it to restore at termination
	and     al,ah                   ; mask to enable interrupt
	jmp     short $+2               ; for 286's
	out     dx,al                   ; write out new mask value

installdone:

endif   ;OEM

assume  ds:EMULATOR_DATA
	pop     ds
	ret


page
;       __FPTERMINATE87
;
;       This routine should do the OEM 8087 cleanup.  This routine is called
;       before the program exits.
;
;       DS = EMULATOR_DATA

__FPTERMINATE87:
	push    ds
	push    ax
	push    dx

ifdef   OEM
	mov     ah,SETVECOP
	mov     al,[oem1].intnum
else
	mov     ax,SETVECOP shl 8 + 2
endif   ;OEM
	lds     dx,[OldNMIVec]
	int     OPSYS

ifdef   OEM

;       reset 8259 IMR's to original state

	push    cs
	pop     ds                      ; DS = CS
assume  ds:EMULATOR_TEXT
	cmp     [oem1].aocw1m,0         ; did we have to change 1st 8259 IMR
	je      term2nd8259             ;   no - check 2nd 8259
	mov     al,[aoldIMR]            ; get old IMR
	mov     dx,[oem1].a8259m        ; get 1st 8259 (A0=1) port #
	out     dx,al                   ; restore IMR

term2nd8259:
	cmp     [oem1].bocw1m,0         ; did we have to change 2nd 8259 IMR
	je      terminatedone           ;   no
	mov     al,[boldIMR]            ; get old IMR
	mov     dx,[oem1].b8259m        ; get 2nd 8259 (A0=1) port #
	out     dx,al                   ; restore IMR

terminatedone:

endif   ;OEM

	pop     dx
	pop     ax
	pop     ds
assume  ds:EMULATOR_DATA
	ret


;       Forced cleanup of 8087 exception handling on Control-C

ifndef  _NOCTRLC
ctlcexit:
	push    ax
	push    dx
	push    ds
	call    __FPTERMINATE87         ; forced cleanup of exception handler
	lds     dx,[ctlc]               ; load old control C vector
	mov     ax,SETVECOP shl 8 + CTLCVEC
	int     OPSYS
	pop     ds
	pop     dx
	pop     ax
	jmp     [ctlc]                  ; go through old vector
endif   ;_NOCTRLC

page
;       __fpinterrupt87
;
;       This is the 8087 exception interrupt routine.
;
;       All OEM specific interrupt and harware handling should be done in
;       __fpintreset because __FPEXCEPTION87 (the OEM independent 8087
;       exception handler) may not return.  __FPEXCEPTION87 also turns
;       interrupts back on.
;

PENDINGBIT=     80h             ; Bit in status word for interrupt pending

public __fpIRQ13
__fpIRQ13:
	cli

	WASTE_TIME  70

	push    ax
	xor     al, al
	NULL_JMP
	out     0f0h, al        ; reset busy line.
	NULL_JMP
	mov     al, 65h
	NULL_JMP
	out     0a0h, al        ; EOI slave irq 5
	NULL_JMP
	mov     al, 62h
	NULL_JMP
	out     20h, al         ; EOI master irq 2
	NULL_JMP
	pop     ax


	sub     sp, 2

	push    bp
	mov     bp, sp

	fnstsw  [bp+2]
	WASTE_TIME
	push    ax
	xor     al, al
	NULL_JMP
	out     0f0h, al        ; reset busy line.
	NULL_JMP
	pop     ax

	pop     bp

	fnclex                  ; 486 bug - must wait till after last
				; "out f0" to clear fp exceptions
				; or IGNNE# will be permanently active.
	WASTE_TIME
	push    ax
	xor     al, al
	NULL_JMP
	out     0f0h, al        ; reset busy line.
	NULL_JMP
	pop     ax

	fnclex                  ; 486 bug - must wait till after last
				; "out f0" to clear fp exceptions
				; or IGNNE# will be permanently active.
	WASTE_TIME
	push    ax
	xor     al, al
	NULL_JMP
	out     0f0h, al        ; reset busy line.
	NULL_JMP
	pop     ax

;       fnclex                  ;Now this is safe.

	jmp     __FPEXCEPTION87P


public __fpinterrupt87
__fpinterrupt87:
assume  ds:nothing
	nop

	push    bp
	mov     bp, sp
	sub     sp, 2

	fnstsw  word ptr [bp-2]     ; Store out exceptions

	push    cx                  ; waste time
	mov     cx, 3
self:
	loop    self
	pop     cx

	test    byte ptr [bp-2],PENDINGBIT  ; Test for 8087 interrupt

	mov     sp, bp
	pop     bp

	jz      not87int                    ; Not an 8087 interrupt.

ifdef   OEM
	call    __fpintreset    ; OEM interrupt reset routine
endif   ;OEM

	call    __FPEXCEPTION87 ; 8087 error handling - may not return
				; this routine turns interrupts back on

ifdef   OEM
	cmp     [oem1].share,0  ; Should we execute the old interrupt routine?
	jnz     not87int        ;    if so then do it
				;    else return from interrupt

;       If you fall through here to do further hardware resetting, things
;       may not always work because __FPEXCEPTION87 does not always return
;       This only happens when the 8087 handler gets an exception that is
;       a fatal error in the language runtimes.  I.e., divide by zero
;       is a fatal error in all the languages, unless the control word has
;       set to mask out divide by zero errors.

endif   ;OEM

done8087:
	iret

not87int:
	sub     sp, 4

	push    bp
	mov     bp, sp

	push    ds
	push    ax

	mov     ax, EMULATOR_DATA
	mov     ds, ax
	assume  ds:EMULATOR_DATA

	mov     ax, word ptr [OldNMIVec+2]      ; segment of OldNMIVec
	mov     [bp+4], ax

	mov     ax, word ptr [OldNMIVec]        ; offset of OldNMIVec
	mov     [bp+2], ax

	pop     ax
	pop     ds
	mov     sp, bp
	pop     bp

	retf                    ; jmp  [OldNMIVec]. We should not return.


ifdef   OEM


__fpintreset:
	push    ax
	push    dx
	mov     al,[oem1].aocw2 ; Load up EOI instruction.
	or      al,al           ; Is there at least one 8259 to be reset?
	jz      Reset8259ret    ; no
	mov     dx,[oem1].a8259
	out     dx,al           ; Reset (master) 8259 interrupt controller.
	mov     al,[oem1].bocw2 ; Load up EOI instruction.
	or      al,al           ; Is there a slave 8259 to be reset?
	jz      Reset8259ret
	mov     dx,[oem1].b8259
	out     dx,al           ; Reset slave 8259 interrupt controller.

Reset8259ret:
	pop     dx
	pop     ax
	ret

endif   ;OEM

ifdef   _NO87INSTALL
__FPINSTALLNO87:
	push    bx
	push    es
	push    ax
	push    dx
	push    ds

	mov     ax,cs                   ; Move current CS to DS for opsys calls.
	mov     ds,ax
assume  ds:EMULATOR_TEXT  r
	
; Save old interrupt vector.
; Ask operating system for vector.

ifdef   OEM
	mov     al,[oem1].intnum        ; Interrupt vector number.
	mov     ah,GETVECOP             ; Operating system call interrupt.
else
	mov     ax,GETVECOP shl 8 + 2   ; get interrupt vector 2
endif   ;OEM
	int     OPSYS                   ; Call operating system.
	mov     word ptr [OldNMIVec],bx ; Squirrel away old vector.
	mov     word ptr [OldNMIVec+2],es

; Have operating system install interrupt vectors.

	mov     dx,offset __fpinterruptno87 ; Load DX with fake 8087 interrupt handler.
ifdef   OEM
	mov     ah,SETVECOP             ; Set interrupt vector code in AH.
	mov     al,[oem1].intnum        ; Set vector number.
else
	mov     ax,SETVECOP shl 8 + 2   ; set interrupt vector 2
endif   ;OEM
	int     OPSYS                   ; Install vector.

	pop     ds
assume  ds:nothing
	pop     dx
	pop     ax
	pop     es
	pop     bx
	
	ret

__fpinterruptno87:
	jmp     [OldNMIVec]             ; will use CS: override

__FPTERMINATENO87:
	push    ds
	push    ax
	push    dx

	mov     ax,cs
	mov     ds,ax
assume  ds:EMULATOR_TEXT

ifdef   OEM
	mov     ah,SETVECOP
	mov     al,[oem1].intnum
else
	mov     ax,SETVECOP shl 8 + 2
endif   ;OEM
	lds     dx,[OldNMIVec]
assume  ds:nothing
	int     OPSYS

	pop     dx
	pop     ax
	pop     ds

	ret

endif   ;_NO87INSTALL

EMULATOR_TEXT   ends

	end