page ,132
subttl emdos.asm - Initialization and Termination
;***
;emdos.asm - Initialization and Termination
;
; Copyright (c) 1987-89, Microsoft Corporation
;
;Purpose:
; Initialization and Termination
;
; This Module contains Proprietary Information of Microsoft
; Corporation and should be treated as Confidential.
;
;Revision History: (Also see emulator.hst)
;
; 12-10-89 WAJ Added MTHREAD DS == 0 check.
;
;*******************************************************************************
comment !
DOS interfaces to emulator/8087 functions
Certain emulator/8087 functions are performed by calling __fpmath
with an function code and arguments.
__fpmath general floating point math package interface used
by the emulator/8087 and float calls interfaces. This
is a far routine and must be far called.
entry:
bx = 0 initialize floating point math
dx:ax = task data area (dx = segment , ax = size)
extra size is used to increase floating point stack
(can pass segmented address of __fptaskdata in dx:ax)
si = environment segment
returns:
ax = 0 if successful and using software floating point
1 if successful and using 8087
negative if error
bx = 1 reset (FINIT)
bx = 2 terminate floating point math
bx = 3 set error signal address
dx:ax = segment:offset of user error handler
bx = 4 load user control word
(user should not use FLDCW instruction directly)
ax = user control word value
bx = 5 store user control word
returns:
ax = user control word value
bx = 6 truncate TOS to integer TOS
ax = user control word (only use round mode)
bx = 7 truncate TOS to 32-bit integer in DX:AX
ax = user control word (only use round mode)
bx = 8 store user status word
returns:
ax = user status word value
bx = 9 clear exceptions
bx = 10 return number of stack elements in ax
bx = 11 returns 1 if using 80x87, 0 if not
bx = 12 if ax = 0, turn off extended stack. if ax = 1, turn on e.s.
QB3 version
bx = 0 init, ax = initCW, es = PSP
bx = 1 reset
bx = 2 term
bx = 3 set vectors
bx = 4 reset vectors
!
glb <functab>
functab label word
dw initialization ; 0 - initialize emulator/8087
dw reset ; 1 - reset emulator/8087 stack
dw termination ; 2 - terminate emulator/8087
ifdef QB3
dw set_vectors ; 3 - set interrupt vectors
dw rst_vectors ; 4 - reset interrupt vectors
SizeJmpTab equ 4
else ;not QB3
dw setsignal ; 3 - set error signal address
dw loadcontrolword ; 4 - load user control word
dw storecontrolword ; 5 - store user control word
dw truncateTOS ; 6 - truncate TOS to integer TOS
dw truncateTOSto32int ; 7 - truncate TOS to integer in DX:AX
dw storestatusword ; 8 - store user status word
dw clearexceptions ; 9 - clear execeptions
dw NumStack ; 10 - report number of elements in stack
dw ReturnHave8087 ; 11 - report if using coprocessor
dw SetExtendedStack ; 12 - turn on or off extended stack
SizeJmpTab equ 12
endif ;not QB3
endfunc label word
szfunctab= endfunc - functab
public __fpmath ; emulator entry point
; (if linked with user program)
__fpmath proc far
cmp bx, SizeJmpTab
ja RetFPErr
shl bx,1
push ds ; save DS
ifdef QB3
push es
push ax
push cx
push dx
push si
push di
endif
ifdef MTHREAD
or bx,bx ; check for initialization
jz callfunc ; yes - skip set up of ds
push ax ; preserve AX = __fpmath argument
LOADthreadDS ; macro in emthread.asm
; loads thread's DS; trashes AX
mov ax, ds
or ax, ax ; check for DS of zero.
pop ax
jz FPMathRet
callfunc:
else ;MTHREAD
ifdef standalone
xor cx,cx
mov ds,cx
mov ds,ds:[TSKINT*4+2] ; point to task data area
elseifdef _COM_
mov ds, [__EmDataSeg]
else
mov cx, edataBASE
mov ds,cx
endif ;standalone
endif ;MTHREAD
call functab[bx]
ifdef QB3
pop di
pop si
pop dx
pop cx
pop ax
pop es
endif
lab FPMathRet
pop ds ; restore DS
pub emuret
ret
RetFPErr:
or ax, -1
mov dx, ax
jmp emuret
__fpmath endp
ProfBegin DOS
subttl emdos.asm - Initialization and Termination
page
;*********************************************************************;
; ;
; Initialization and Termination ;
; ;
;*********************************************************************;
wastetime macro
push cx
mov cx,20 ;; wait for a short time
loop $
pop cx
endm
ifndef only87
CHIPKEY db 'NO87='
CHIPKEYLEN equ $ - CHIPKEY
crlf db 13,10
endif ;only87
ifdef standalone
Installed db 0 ; installation flag
pub sizeerror
mov ax,-1 ; return size error
stc
ret
endif ;standalone
; initialization
;
; entry dx:ax = task data area (segment and size) for standalone
; si = DOS environment segment for NO87 lookup
pub initialization
ifdef QB3
mov [initCW],ax ; save initial BASIC control word
endif
setstacklimits macro
mov di,offset BEGstk ; di = base of register stack
mov [BASstk],di ; initialize stack base
mov cx,Reg87Len ; cx = register length
xchg ax,dx ; ax = task data segment size
sub ax,di ; ax = number bytes for stack
cwd ; dx:ax = number of bytes
div cx ; ax = number of entries
mul cx ; ax = number of bytes
add ax,di ; ax = top of stack
sub ax,cx ; Leave room for one on overflow
mov [LIMstk],ax ; set top of stack
endm
ifdef standalone
; check task data area sizes for correctness
cmp ax,offset __fptaskdata ; compare against minimum size
jb sizeerror ; too small
mov ds,dx ; set up task data segment
xchg dx,ax ; set up size
mov ax,25h*256 + TSKINT ; set TASK DATA pointer vector
int 21h
setstacklimits
endif ;standalone
ifdef MTHREAD
ALLOCthreadDS ; macro in emthread.asm
mov dx,(offset __fptaskdata)-cvtbufsize
; set up size in dx
; cvt buf not part of stack
setstacklimits
endif ;MTHREAD
ifdef QP
mov ax, edataOFFSET BEGstk ; initialize BASstk, CURstk, LIMstk
mov [BASstk], ax ; QuickPascal has no data initialization
mov [CURstk], ax
mov ax, edataOFFSET ENDstk
sub ax, 2*Reg87Len
mov [LIMstk], ax
endif ;QP
ifndef frontend
ifdef DOS5
push ss ; current stack segment selector
push ds
mov ax,offset SSalias
push ax ; address of SSalias
os2call DOSCREATECSALIAS ; get SS alias for exception handling
endif ;DOS5
endif ;frontend
ifdef DOS3and5
push ds
mov ax,offset protmode
push ax
os2call DOSGETMACHINEMODE ; get machine mode flag
endif ;DOS3and5
ifdef MTHREAD
mov ax,ds
cmp ax,EMULATOR_DATA ; check for thread 1
je initcheckenv ; yes - go look for NO87=
; other threads should copy thread 1's Have8087 value
; and then go to initfinish
push ds
mov ax,EMULATOR_DATA
mov ds,ax
mov al,[Have8087]
pop ds
mov [Have8087],al
jmp initfinish
endif ;MTHREAD
pub initcheckenv
ifdef frontend
mov [Have8087],0 ; indicate no 8087
else
ifndef only87
push ds
; Examine the environment looking for the NO87= switch
or si,si ; check for no environment passed in
je init1 ; don't look for NO87=
mov es,si ; ES = environment segment
push cs
pop ds
xor di,di ; DI -> 1st byte of environment
cld
pub envstart
cmp byte ptr es:[di],0 ; 1st byte zero means end of env.
je init1 ; continue with initialization
mov cx,CHIPKEYLEN ; Length of key 'NO87='
mov si,offset CHIPKEY ; key string address
repe cmpsb
je envwrtmsg
mov cx,7FFFh ; Scan rest of environment
xor al,al ; for 0
repne scasb
je envstart ; yes - check next entry
jmp short init1 ; UNDONE - bad environment if here
pub envwrtmsg
mov cx,7FFFh
mov al,' ' ; skip leading blanks
repe scasb
dec di
mov dl,es:[di] ; Get character of message
or dl,dl ; Do we have a null?
jz envmsgend ; If so we're done
pub envwrtlp
xor ax,ax ;** vvv ; scan for a null byte
mov cx,7FFFh
mov bx,di ; save offset of string
repne scasb
dec di
sub di,bx
mov cx,di ; count of characters before null byte
;
; write out NO87= environment string to standard output
;
ifdef DOS5
mov di,bx ; restore offset of string
push ax
mov ax,sp ; allocate space for return count
mov bx,1
push bx ; file handle (standard output)
push es
push di ; address of buffer
push cx ; number of bytes to write
push ss
push ax ; address for return count
os2call DOSWRITE
;
; write out CR-LF pair to standard output
;
mov ax,sp ; pointer to space for return count
mov bx,1
push bx ; file handle (standard output)
push cs
mov di,offset crlf
push di ; address of CR-LF pair
mov bx,2
push bx ; number of bytes to write: 2
push ss
push ax ; address for return count
os2call DOSWRITE
pop bx ;** ^^^ ; deallocate space for return count
else
push es
pop ds
mov dx,bx ; ds:dx = string
mov bx,1 ; bx = file handle (1)
mov ah,40H
int 21h ; call DOS - write string
push cs
pop ds
mov dx,offset crlf ; ds:dx = CR/LF
mov cx,2 ; cx = 2 bytes
mov ah,40H
int 21h ; call DOS - write string
endif
pub envmsgend
pop ds ; restore user data area
mov [Have8087],0 ; indicate emulation
ifdef _NO87INSTALL
jmp initinstallno87 ; go call __FPINSTALLNO87
else ;_NO87INSTALL
jmp initvec ; initialize for emulation
endif ;_NO87INSTALL
pub init1
pop ds ; restore user data area
endif ;only87
; check if 8087/80287 is present
ifdef DOS3and5
cmp [protmode],0 ; check for protect mode
jne prot287chk ; yes - check for 287
endif ;DOS3and5
ifdef DOS3
; real mode 8087/80287 check
ifdef PCDOS
PCBIOSEQ equ 11H ; PC BIO's Equipment determination call.
COPROCESSORMASK equ 2H ; Mask for Coprocessor sense switch.
int PCBIOSEQ ; PC-DOS Bios Equipment
and al,COPROCESSORMASK ; Coprocessor present?
shr al,1 ; al = 0 if no 8087/80287 , 1 = if yes
ifdef only87
jz installerror ; error if no 8087/80287
endif ;only87
else
fninit ; Initialize the 8087.
wastetime
xor ax,ax ; Clean AX.
mov [statwd],ax ; Clear temporary.
fnstcw [statwd] ; have bits 033Fh set if 8087
wastetime
and [statwd],0F3Fh ; (was 1F3Fh, but now allows for 80387-A1 step)
cmp [statwd],033Fh
jnz realno87 ; no 8087 or 287
; 80287 can fool you - also check for status word
fnstsw [statwd] ; save status word
wastetime
inc ax ; al = 1 (assume have an 80287)
test [statwd],0B8BFh ; should be off if present
pub realno87
jz realhave87
ifdef only87
jmp short installerror ; error if no 8087/80287
else
xor ax,ax ; al = 0
endif ;only87
pub realhave87
endif ;PCDOS
MOV [Have8087],al
endif ;DOS3
ifdef DOS3and5
jmp short initinstall
endif ;DOS3and5
ifdef DOS5
; protect mode 80287 check
pub prot287chk
push ds
.286
push offset Have8087 ; directly change Have8087
push 3 ; 3rd byte is coprocessor flag
push 0 ; reserved parameter
ifndef DOS5only
.8086
endif
os2call DOSDEVCONFIG
ifdef only87
cmp [Have8087],0 ; error if no 87 present
je installerror
endif ;only87
endif ;DOS5
endif ;frontend
; check if floating point emulator/8087 already installed (device driver)
pub initinstall
ifndef QB3
ifndef frontend
ifndef only87
cmp [Have8087],0 ; check for 8087/80287
ifdef _NO87INSTALL
jne initcontinue
pub initinstallno87
extrn __FPINSTALLNO87:near
call __FPINSTALLNO87
jmp initvec
initcontinue:
else ;_NO87INSTALL
je initvec ; no - don't install hardware
endif ;_NO87INSTALL
endif ;only87
ifdef DOS3and5
cmp [protmode],0 ; check for protect mode
jne initprotinstall ; yes - don't install hardware
endif ;DOS3and5
ifdef DOS5only
jmp initprotinstall
endif
ifdef DOS3
ifdef standalone
cmp [Installed],0 ; note - in code segment (not task)
jnz initvec ; installed - skip installation
endif ;standalone
extrn __FPINSTALL87:near
call __FPINSTALL87 ; OEM installation
jnc initvec
endif ;DOS3
pub installerror
mov ax,-2 ; return installation error
stc
ret
ifdef DOS5
pub initprotinstall
.286
push 16 ; exception error
push cs
push offset protexception
push ds
push offset oldvec+4 ; address for old exception vector
ifndef DOS5only
.8086
endif
os2call DOSSETVEC
endif ;DOS5
endif ;frontend
endif ;QB3
; set up interrupt vectors for emulator or fixup-on-the-fly
pub initvec
ifdef DOS3and5
cmp [protmode],0
jne initvecprot ; yes - protect mode setup
endif ;DOS3and5
ifdef DOS3
; real mode emulation and fixup on the fly vector setup
ifndef QB3
call set_vectors
endif
endif ;DOS3
ifdef DOS3and5
jmp short initfinish
endif
ifdef DOS5
pub initvecprot
ifndef only87
cmp [Have8087],0 ; emulation?
jne initfinish ; no - don't setup vector
.286
push 7 ; emulation
push cs
push offset protemulation
push ds
push offset oldvec ; address for old emulation vector
ifndef DOS5only
.8086
endif
os2call DOSSETVEC
endif ;only87
endif ;DOS5
; finish initialization
pub initfinish
call reset ; reset (0), FINIT if 8087 present
ifdef QB3
mov ax,[initCW]
else
mov ax,InitControlWord ; setup initial control word
endif
call loadcontrolword
ifndef QB3
xor ax,ax
mov word ptr [SignalAddress],ax ; clear SignalAddress
mov word ptr [SignalAddress+2],ax
endif
ifdef MTHREAD
mov [ExtendStack],1
endif ;MTHREAD
ifndef only87
ifdef LOOK_AHEAD
ifdef DOS3and5
mov ax, offset DOSLookAhead
cmp [protmode], 0
je SetLookAheadRoutine
mov ax, offset ProtLookAhead
SetLookAheadRoutine:
mov [LookAheadRoutine], ax
endif ;DOS3and5
endif ;LOOK_AHEAD
endif ;not only87
mov al,[Have8087]
cbw ; ax = 0 or 1 depending on 8087
ret
ifdef MTHREAD
lab LoadDS_EDI ; this is used from emds.asm
push bx
push cx
push dx
mov bx, DGROUP
mov ds, bx
call __FarGetTidTab
mov ds, dx
mov di, ax
add di, __fpds
pop dx
pop cx
pop bx
ret
endif ;MTHREAD
;------ termination ----------------------------------------------------
pub termination
ifdef DOS3and5
cmp [protmode],0 ; are we in protect mode?
jne termprot ; yes
endif ;DOS3and5
ifdef DOS3
; real mode termination
ifndef QB3
call rst_vectors
endif
ifndef frontend
ifndef only87
cmp [Have8087],0 ; Non zero if 8087 chip exists
ifdef _NO87INSTALL
jne termcontinue
extrn __FPTERMINATENO87:near
call __FPTERMINATENO87
ret
termcontinue:
else ;_NO87INSTALL
je termrealdone
endif ;_NO87INSTALL
endif ;only87
FNINIT ; Clean up 8087.
ifndef QB3
extrn __FPTERMINATE87:near
call __FPTERMINATE87 ; OEM 8087 cleanup routine
endif
endif ;frontend
pub termrealdone
ret
endif ;DOS3
ifdef DOS5
; protect mode termination
pub termprot
; UNDONE - don't do any cleanup - should be handled by DOS
ifndef frontend ; UNDONE - should not be needed
push [SSalias]
os2call DOSFREESEG ; free up SSalias
endif ;frontend
ifdef MTHREAD
FREEthreadDS ; defined in emthread.asm
; uses DOSFREESEG
endif ;MTHREAD
ret
endif ;DOS5
subttl emdos.asm - reset and clearexceptions
page
;*********************************************************************;
; ;
; Reset and Clearexceptions ;
; ;
;*********************************************************************;
pub reset
ifndef frontend
ifndef only87
cmp [Have8087],0 ; Nonzero if 8087 chip exists
je noFINIT
endif ;only87
FNINIT ; Initialize 8087.
endif ;frontend
pub noFINIT
mov ax,[BASstk]
mov [CURstk],ax ; reset stack to bottom
; fall into clearexceptions
pub clearexceptions
xor ax,ax
ifndef frontend
ifndef only87
cmp al,[Have8087] ; Nonzero if 8087 chip exists
je noFCLEX
endif ;only87
FCLEX ; clear exceptions
endif ;frontend
pub noFCLEX
ifndef only87
mov [StatusWord],ax ; clear status word
endif ;only87
mov [UserStatusWord],ax ; clear exception status word
ifdef QB3
mov ax,[initCW]
call loadcontrolword ; reload 8087 control word
endif ;QB3
ret
subttl emdos.asm - setsignal ---------------------------------
page
;*********************************************************************;
; ;
; Setsignal ;
; ;
;*********************************************************************;
ifndef QB3
pub setsignal
mov word ptr [SignalAddress],ax ; set offset
mov word ptr [SignalAddress+2],dx ; set segment
ret
endif ;QB3
ifdef DOS3
pub set_vectors
mov cx,NUMVEC ; save old vectors under DOS 3
mov ax,35h*256 + BEGINT ; get vector
mov di,offset oldvec ; di = old vector table
pub getvecs
int 21h
inc ax
mov [di],bx ; save old vector
mov [di+2],es
add di,4
loop getvecs
ifndef only87
mov dx,offset DStrap ; assume emulator
mov si,offset SOtrap
mov di,offset FWtrap
endif ;only87
ifndef frontend
ifndef only87
cmp [Have8087],0 ; are we using 8087 ?
jz setvectors ; no - go ahead and set them
endif ;only87
mov dx,offset DSFixUpOnFly ; set up for fixup-on-the-fly
mov si,offset SOFixUpOnFly
mov di,offset FWFixUpOnFly
endif ;frontend
pub setvectors
push ds
push cs
pop ds
mov ax,25h*256 + BEGINT
mov cx,8 ; 8 vectors for DStrap
pub vecloop
int 21h ; set vector
inc ax ; bump to next one
loop vecloop
mov dx,si ; set Segtrap
int 21h
inc ax
mov dx,di ; set FWtrap
int 21h
pop ds ; restore task data area
ret
pub rst_vectors
mov cx,NUMVEC
mov ax,25h*256 + BEGINT ; set vector
mov di,offset oldvec ; di = old vector table
pub termresetvecs
push ds
lds dx,[di] ; get old vector value
int 21h
pop ds
inc ax
add di,4
loop termresetvecs
ret
endif ;DOS3
pub NumStack ; returns the number of stack elements in ax
xor dx, dx ; dx will count nonzero elements
ifndef only87
cmp Have8087, 0
je CountEmulatorStack
endif ;only87
sub sp, 14 ; need 14 bytes for fstenv
mov bx, sp
fstenv ss:[bx]
fldcw ss:[bx] ; reset control word
mov ax, ss:[bx+4] ; put tag word in ax
add sp, 14 ; reset stack
mov cx, 8
pub NotEmptyLoop
mov bx, ax
shr ax, 1
shr ax, 1
and bx, 3
cmp bx, 3
je StackEntryEmpty
inc dx ; stack element was not empty
pub StackEntryEmpty
loop NotEmptyLoop
pub CountEmulatorStack
mov ax, CURstk
sub ax, BASstk
mov bl, Reg87Len
div bl
add ax, dx ; add elements on 80x87 stack
ret
ReturnHave8087 proc near
mov al, [Have8087]
cbw
ret
ReturnHave8087 endp
SetExtendedStack proc near
mov [ExtendStack], ax
ret
SetExtendedStack endp
ProfEnd DOS
