Source code of Windows XP (NT5)
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TITLE DXSTRT.ASM -- Dos Extender Startup Code
; Copyright (c) Microsoft Corporation 1988-1991. All Rights Reserved.
;****************************************************************
;* *
;* DXSTRT.ASM - Dos Extender Startup Code *
;* *
;****************************************************************
;* *
;* Module Description: *
;* *
;* This module contains the executive initialization code for *
;* the Dos Extender. The module DXBOOT.ASM contains the code *
;* specific to starting up the Dos Extender. The module *
;* DXINIT.ASM contains the code specific to starting up the *
;* child program of the Dos Extender. The code in these *
;* two modules is discarded at the end of the initialization. *
;* The code in this module calls the initialization routines *
;* in the other to init modules, and then performs the final *
;* juggling of things to throw away the low memory init code, *
;* and transfer control to start up the child program. *
;* *
;****************************************************************
;* Revision History: *
;* *
;* 01/09/91 amitc At exit time Co-Processor being reset *
;* 08/08/90 earleh DOSX and client privilege ring determined *
;* by equate in pmdefs.inc *
;* 12/08/89 jimmat Added call to reenable EMM driver. *
;* 08/29/89 jimmat Restores Int 2Fh vector at exit *
;* 08/20/89 jimmat Removed A20 code, since HIMEM version 2.07 *
;* A20 code now works properly. *
;* 06/28/89 jimmat Now calls OEM layer instead of NetMapper *
;* 06/16/89 jimmat Implemented Windows/386 startup/exit Int *
;* 2Fh calls and ifdef'd combined EXE code *
;* 05/17/89 jimmat ChildTerminationHandler sets its SS:SP *
;* 04/18/89 jimmat Added calls to init/term NetBIOS mapper *
;* 03/28/89 jimmat Incorporated bug fix from GeneA related *
;* to nested GP faults in ChildTermHandler *
;* 03/11/89 jimmat Added support for TSS & LDT *
;* 03/07/89 jimmat converted to use WDEB386 *
;* 02/27/89 (GeneA): shrink initial memory block size on entry *
;* 02/25/89 (GeneA): added support for combined exe file where *
;* the Dos Extender and the child reside in the same exe *
;* file. *
;* 02/17/89 (GeneA): fixed error termination code for startup *
;* errors that occur while in protected mode *
;* 02/14/89 (GeneA): added code to reduce size of real mode *
;* code segment to throw away initialization code. *
;* 01/31/89 (GeneA): created by copying code from the old *
;* DXINIT.ASM *
;* 18-Dec-1992 sudeepb Changed cli/sti to faster FCLI/FSTI
;****************************************************************
.286p
; -------------------------------------------------------
; INCLUDE FILE DEFINITIONS
; -------------------------------------------------------
.sall
.xlist
include segdefs.inc
include gendefs.inc
include pmdefs.inc
include hostdata.inc
include dpmi.inc
include intmac.inc
.list
; -------------------------------------------------------
; GENERAL SYMBOL DEFINITIONS
; -------------------------------------------------------
WIN386_INIT equ 1605h ;Win/386 startup Int 2Fh
WIN386_EXIT equ 1606h ;Win/386 shutdown Int 2Fh
WIN386_DOSX equ 0001h ;Win/386 init/exit really DOSX flag
; -------------------------------------------------------
; EXTERNAL SYMBOL DEFINITIONS
; -------------------------------------------------------
extrn InitDosExtender:NEAR
extrn RestoreRMIntrVectors:NEAR
extrn SaveRMIntrVectors:NEAR
extrn EnterRealMode:NEAR
extrn EnterProtectedMode:NEAR
extrn InitializeOEM:NEAR
extrn TerminateOEM:NEAR
externNP NSetSegmentAccess
extrn DupSegmentDscr:NEAR
extrn EMMEnable:NEAR
ifdef WOW_x86
externFP NSetSegmentDscr
else
externFP NSetGDTSegmentDscr
ENDIF; WOW_x86
extrn PMIntr19:NEAR
extrn PMIntr13:NEAR
extrn PMIntr31:NEAR
extrn PMIntr28:NEAR
extrn PMIntr25:NEAR
extrn PMIntr26:NEAR
extrn PMIntr4B:NEAR
extrn PMIntrDos:NEAR
extrn PMIntrMisc:NEAR
extrn PMIntrVideo:NEAR
extrn PMIntrMouse:NEAR
extrn PMIntrIgnore:NEAR
extrn PMIntrEntryVector:NEAR
extrn PMFaultEntryVector:NEAR
ifdef NEC_98 ;
extrn PMIntr11dummy:NEAR
extrn PMIntrPrinter:NEAR
extrn PMIntrCalTi:NEAR
extrn PMIntrGraph:NEAR
endif ;NEC_98 ;
; -------------------------------------------------------
; DATA SEGMENT DEFINITIONS
; -------------------------------------------------------
; -------------------------------------------------------
DXDATA segment
extrn A20EnableCount:WORD
extrn lpfnUserMouseHandler:DWORD
extrn lpfnUserPointingHandler:DWORD
extrn f286_287:BYTE
extrn cDPMIClients:WORD
extrn selCurrentHostData:WORD
extrn segCurrentHostData:WORD
ifdef WOW_x86
extrn FastBop:fword
endif
extrn DpmiFlags:WORD
org 0
public rgwStack,npEHStackLimit,npEHStacklet, selEHStack,
;
; Pmode fault handler stack used during initialization only.
;
dw 80h dup (?)
rgwStack label word
;
; This is the stack area used while running in the interrupt reflector.
; This is divided up into a number of stack frames to allow reentrant
; execution of the interrupt reflector. The stack pointer pbReflStack
; indicates the current stack frame to use. Each entry into the interrupt
; reflector decrements this variable by the size of the stack frame, and
; each exit from the interrupt reflector increments it.
C_STKFRAME = 36
CB_REFLSTACK = C_STKFRAME * CB_STKFRAME
if DEBUG ;--------------------------------------------------------
public StackGuard
StackGuard dw 1022h ;unlikely value to check for stk overrun
endif ;--------------------------------------------------------
public pbReflStack,bReflStack
if DBG
bReflStack db CB_REFLSTACK dup (0AAh)
else
bReflStack db CB_REFLSTACK dup (?)
endif
;----------------------------------------------------------------------------
; The following stack is used for hw interrupts while booting where
; the kernel or ntvdm switches the stack before an interrupt is reflected.
;----------------------------------------------------------------------------
CB_HWINTRSTACK = 1000h
if DBG
bHwIntrStack db CB_HWINTRSTACK dup (0AAh)
else
bHwIntrStack db CB_HWINTRSTACK dup (?)
endif
public pbHwIntrStack
pbHwIntrStack dw bHwIntrStack + CB_HWINTRSTACK
pbReflStack dw bReflStack + CB_REFLSTACK
npEHStackLimit dw offset DGROUP:rgwStack
npEHStacklet dw offset DGROUP:rgwStack
selEHStack dw 0
public cdscGDTMax, selGDTFree, segGDT, selGDT
cdscGDTMax dw CDSCGDTDEFAULT
selGDTFree dw ? ;head of list of free descriptors in GDT
segGDT dw 0 ;real mode paragraph address of the GDT
; This variable always stores the real mode
; paragraph address
selGDT dw 0 ;current mode segment/selector for the GDT
; segment. This variable holds the real
; mode paragraph address during initialization
; and then holds the protected mode selector
; when running in protected mode.
public bpGDT, bpGDTcb, bpGDTbase
bpGDT label fword
bpGDTcb dw ?
bpGDTbase dd ?
public segIDT, selIDT
segIDT dw 0
selIDT dw 0
public bpIDT, bpIDTcb, bpIDTbase
bpIDT label fword
bpIDTcb dw ?
bpIDTbase dd ?
public bpRmIVT
bpRmIVT dq 0FFFFh ;This is the segment descriptor for the real
; mode interrupt vector table.
public lpfnXMSFunc
lpfnXMSFunc dd 0 ;far pointer to XMS memory driver entry point
public idCpuType
idCpuType dw 0
public segPSP, selPSP
segPSP dw ? ;segment address of Dos Extender PSP
selPSP dw ? ;selector for Dos Extender PSP
; code during processing of GP faults
public selPSPChild, segPSPChild
segPSPChild dw ? ;real mode segment address of child's PSP
; note the following in 1, so that in low mem heap management, we can use
; selPSPChild to mark the owner of the memory.
selPSPChild dw 1 ;selector of child program's PSP
public DtaSegment, DtaOffset, DtaSelector
DtaSegment dw 0
DtaSelector dw 0
DtaOffset dw 0
public regChildSP, regChildSS, regChildIP, regChildCS
regChildSP dw ? ;initial user stack pointer from exe file
regChildSS dw ? ;initial user stack segment from exe file
regChildIP dw ? ;initial user program counter from exe file
regChildCS dw ? ;initial user code segment from exe file
public hmemDOSX
hmemDOSX dw 0
IFDEF ROM
public segDXCode, segDXData
segDXCode dw ? ;holds real mode paragraph address
; of the code segment
segDXData dw ? ;holds real mode paragraph address
; of the data segment
ENDIF
ifdef NEC_98
public fPCH98
fPCH98 db 0 ;NZ if running on a Micro Channel system
public fNHmode
fNHmode db 0 ;NZ if running on a Hmode system
endif ;!NEC_98
public fFaultAbort, ExitCode
fFaultAbort db 0 ;NZ if terminating due to unrecoverable fault
ExitCode db 0FFh ;exit code to use when terminating
fQuitting db 0
fEMbit db 0FFh ;MSW EM bit at startup (FF = not checked yet)
public fUsingHMA
fUsingHMA db 0
; The one and only Task State Segment is here (it's too small to allocate
; a block for it in extended memory)
public sysTSS
sysTSS TSS286 <>
; After initialization is complete, the following buffers (rgbXfrBuf0 and
; rgbXfrBuf1) are used to transfer data between real mode address space
; and protected mode address space during the processing of various interrupt
; function calls. During the initialization process, these buffers are also
; used as temporary work space as described below:
; CheckCPUType uses the first 6 bytes of rgbXfrBuf0 as scratch space.
; The functions for moving the Dos Extender protected mode code segment
; and the GDT and IDT use rgbXfrBuf0 as buffer space for building a
; parameter block. The child loading code in DXINIT.ASM uses the buffer
; RELOC_BUFFER for holding the base part of the file name (name.exe portion)
; of the child exe file while determining the complete path to the child
; in the case where the child name is specified on the command line. Note,
; this buffer is also used for holding sectors from the relocation table
; while loading the program, but that occurs after the child exe file name
; has been determined.
; The child loading code in DXINIT.ASM also uses rgbXfrBuf1 to hold several
; buffers as well. The locations and purposes of these buffers are
; described in GENDEFS.INC. All of the buffers are defined with equates
; named EXEC_?????
;
; The file search logic in DXFIND.ASM assumes some parameters are setup in
; the rgbXfrBuf1 file name buffers. Some of the code was moved from
; DXINIT.ASM to DXFIND.ASM.
public rgbXfrBuf0, rgbXfrBuf1
public npXfrBuf0, npXfrBuf1
align 2
rgbXfrBuf0 db CB_XFRBUF0 dup (?)
rgbXfrBuf1 db CB_XFRBUF1 dup (?)
npXfrBuf0 dw offset DGROUP:rgbXfrBuf0
npXfrBuf1 dw offset DGROUP:rgbXfrBuf1
DtaBuffer dw 128 dup (0) ; used as the dta for PM if dta changed
; Parameter block for passing to DOS EXEC call to run the child
; program.
;
public exec_par_blk
exec_par_blk dw 0
cmd_off dw OFFSET EXEC_CMNDLINE
cmd_seg dw DXDATA
dw OFFSET EXEC_FCB0
fcb1_seg dw DXDATA
dw OFFSET EXEC_FCB1
fcb2_seg dw DXDATA
; The following variables are used during reading the relocation table
; from the exe file and relocating the child program.
public fhExeFile
public clpRelocItem
public plpRelocItem
fhExeFile dw ? ;DOS file handle for the exe file
clpRelocItem dw ? ;number of relocation items in the exe file
plpRelocItem dw ? ;pointer to next relocation item in the table
szDebugHello label byte
if DEBUG
db 'DOSX: Beginning protected mode initialization.',13,10,0
endif
db 0
FreeMem dw 0
DXDATA ends
; -------------------------------------------------------
page
; -------------------------------------------------------
; CODE SEGMENT VARIABLES
; -------------------------------------------------------
DXCODE segment
extrn CodeEnd:NEAR
extrn ER_DXINIT:BYTE
extrn ER_REALMEM:BYTE
extrn RMDefaultInt24Handler:FAR
public segDXCode, segDXData, selDgroup
segDXCode dw ? ;holds the real mode paragraph address
; of the code segment
segDXData dw ? ;holds the real mode paragraph address
; of the data segment
selDgroup dw ? ;holds the paragraph address/selector for
; DGROUP depending on the current mode
public PrevInt2FHandler
PrevInt2FHandler dd ? ;previous real mode Int 2F handler
DXCODE ends
DXPMCODE segment
extrn CodeEndPM:NEAR
org 0
public selDgroupPM, segDXCodePM, segDXDataPM
selDgroupPM dw ? ;This variable always contains the
; data segment selector
segDXCodePM dw ? ;This variable contains the paragraph
; address of the real mode code segment
segDXDataPM dw ? ;This variable contains the paragraph
; address of the data segment
externFP NSetSegmentDscr
DXPMCODE ends
; -------------------------------------------------------
BeginLowSegment
; -------------------------------------------------------
; DOS EXTENDER ENTRY FUNCTION
; -------------------------------------------------------
;
; This is the program entry point for the Dos Extender. This
; function decides if the Dos Extender is being run as a single
; time operation to extend a single program, or if it is being
; run as a TSR to wait for programs to request its services
; later on.
;
assume ds:PSPSEG,es:PSPSEG,ss:NOTHING
public start
start:
; Set up the initial segment registers.
mov ax,DGROUP
mov ds,ax
assume ds:DGROUP
mov segPSP,es ;save the PSP segment address
mov ss,ax
mov sp,offset DGROUP:rgwStack
assume ss:DGROUP
;
; Set up the INT 24h handler. The default INT 24h handler fails the
; system call in progress, for DPMI compatibility.
;
push ds
mov ax,cs
mov ds,ax
mov dx,offset DXCODE:RMDefaultInt24Handler
mov ax,2524h
int 21h
pop ds
; Issue the Win/386 startup Int 2Fh (almost) first thing
push ds
mov ax,WIN386_INIT ;gives other PM software a chance
xor bx,bx ; to disable itself, release XMS, etc.
mov cx,bx
mov si,bx
mov ds,bx
mov es,bx
assume ds:NOTHING, es:NOTHING
mov dx,WIN386_DOSX
mov di,DXVERSION
int 2Fh
pop ax ;restore ds/es DGROUP addressability
mov ds,ax
mov es,ax
assume ds:DGROUP, es:DGROUP
jcxz Allow_Startup ;if cx still == 0, keep going (we ignore
; all the other possible return values)
mov ExitCode,2 ; otherwise we should abort now
jmp RealModeCleanUp
Allow_Startup:
; Initialize the Dos Extender
call InitDosExtender ;NOTE: passes data to InitChildProgram
jnc @F ; in rgbXfrBuf1 -- don't overwrite it!
jmp strt88
@@:
; Save the state of the MSW EM bit (Emulate Math coprocessor), and turn
; it off (win87em wants it off).
ifndef WOW_x86
smsw ax
out1 <What to do about this?>
test al,01h ;in V86 mode?
jnz @f ; can't do the lmsw if so
push ax
and al,04h
mov fEMbit,al
pop ax
and al,not 04h
lmsw ax
@@:
endif ; WOW_x86
; Switch the machine into protected mode.
FCLI
call SaveRMIntrVectors
SwitchToProtectedMode
public DXPMInit
DXPMInit LABEL BYTE
if DEBUG
Trace_Out "*******************************************************************************"
Trace_Out "*******************************************************************************"
Trace_Out "**** ****"
Trace_Out "**** THIS IS A DEBUG RELEASE THIS IS A DEBUG RELEASE ****"
Trace_Out "**** ****"
Trace_Out "*******************************************************************************"
Trace_Out "*******************************************************************************"
endif
assume ds:DGROUP,es:NOTHING
mov ax,SEL_IDT or STD_RING
mov selIDT,ax
mov ax,SEL_LDT_ALIAS OR STD_RING
mov selGDT,ax
; Initialize the LDT now that we are in protected mode. First, set the
; contents to zero.
mov es,selGDT ; actually LDT
assume es:NOTHING
mov cx,cdscGDTMax
IFDEF WOW
mov di,GDT_SIZE
sub cx,di
ENDIF
shl cx,2 ; CX = words in LDT segment
xor ax,ax ; AX = 0
IFNDEF WOW
mov di,ax
ENDIF
cld
rep stosw ; CX = 0
dec cx ; CX = 0FFFFh
push ax
push cx
mov ax,es ; LDT selector
lsl cx,ax ; LDT size
mov di,SEL_USER and SELECTOR_INDEX
DPMIBOP InitLDT
pop cx
pop ax
;
; Set the two scratch selectors to 64k data starting at zero. Actual
; addresses set as used.
;
cCall NSetSegmentDscr,<SEL_SCR0,ax,ax,ax,cx,STD_DATA>
cCall NSetSegmentDscr,<SEL_SCR1,ax,ax,ax,cx,STD_DATA>
ifndef WOW_x86
mov dx,40h*16
cCall NSetGDTSegmentDscr,<040h,ax,dx,ax,cx,STD_DATA>
endif
; Bop to initialize 32 bit support.
push es
mov ax,SEL_DXCODE OR STD_RING
mov es,ax
assume es:DXCODE
mov di, sp ;original stack offset
push ds
push offset DGROUP:DtaBuffer
push ds
push offset DGROUP:pbReflStack
push ds
push offset DGROUP:rgbXfrBuf1
push ds
push offset DGROUP:rgbXfrBuf0
mov si,sp ;pass stack offset
FBOP BOP_DPMI,InitDosx,FastBop
mov sp, di ;restore stack
pop es
assume es:nothing
call AllocateExceptionStack
FSTI ;don't need ints disabled
; Shrink the size of our real mode code segment to throw away init code.
SwitchToRealMode
mov bx,(offset CodeEnd) + 15
shr bx,4
add bx,segDXCode
sub bx,segPSP
push es
mov es,segPSP
dossvc 4Ah
pop es
call DetermineFreeMemory
mov FreeMem,bx
SwitchToProtectedMode
; Initialize the OEM layer. This can allocate DOS memory, so it goes
; after the final program shrink.
call InitializeOEM ;currently initializes NetBIOS mapper
if1
%OUT InitializeOEM can fail!!!!!
endif
FBOP BOP_DPMI,ResetLDTUserBase,FastBop
; Exec the child application
SwitchToRealMode
FSTI
;; bugbug hack ...... williamh
;; turn off A20 line before we terminate and keep resident.
cmp A20EnableCount, 0
jz A20IsOff
@@:
xmssvc 6
dec A20EnableCount
jnz @B
A20IsOff:
mov ax,segPSP
mov es,ax
assume es:nothing
mov ax,es:[2ch]
mov es,ax
dossvc 49h ; free env block
call DetermineFreeMemory
mov dx,(offset CodeEnd) + 15
shr dx,4
add dx,FreeMem
sub dx,bx
add dx,segDXCode
sub dx,segPSP
mov al,0
dossvc 31h ; tsr.
help: int 3 ; should never get here
jmp help
lea bx, exec_par_blk
lea dx, EXEC_PROGNAME
xor al, al
dossvc 4bh
; If we get here, the EXEC failed for some reason!
mov bx,offset DXCODE:ER_REALMEM ;assume insufficient memory
xchg ax,bx
cmp bx,8 ;is it really?
jz strt88
mov ax,offset DXCODE:ER_DXINIT ;no, use generic msg
strt88:
mov ExitCode,1 ;return NZ exit code
mov dx,cs ;pass msg ptr in DX:AX (ax already set)
push cs ;fake a far call so no fixup
push offset DXCODE:RealModeCleanUp ; needed -- return to clean up
jmp near ptr DisplayErrorMsg
; -------------------------------------------------------
; ChildTerminationHandler -- This routine receives control
; when the child program running under the Dos Extender
; terminates. It will free all resources being used by
; the child. If we were not running TSR, then the Dos
; Extender will complete cleaning up and terminate itself.
;
; Input: none
; Output: none
; Errors: none
; Uses:
assume ds:NOTHING,es:NOTHING,ss:NOTHING
public DosxTerminationHandler
DosxTerminationHandler:
mov ds,selDgroup
mov es,selDgroup
mov ss,selDgroup ;make sure we know where the
mov sp,offset DGROUP:rgwStack ; stack is when we get here
assume ds:DGROUP,es:DGROUP
; Check if we are already in the middle of a termination sequence and
; bail out if so. This will prevent us from hanging up in an infinite
; loop if we get a GP fault while we are quitting.
cmp fQuitting,0
jz @f
jmp chtm90
@@:
mov fQuitting,1
; Terminate the OEM layer
call TerminateOEM ;current term's NetBIOS mapper & low net heap
; Make sure that no interrupt vectors still point to us.
call RestoreRMIntrVectors
; if this is a 80286 & 80287 configuration, we should reset the Co-Processor.
cmp [f286_287],0 ;286 and 287 config ?
jz CTH_Not286And287 ;no.
; reset the 80287 Co-Processor to make sure that it gets out of protected
; mode.
xor al,al ;need to out 0
out 0F1H,al ;reset the coprocessor
CTH_Not286And287:
; If we're aborting due to a processor fault, do some extra clean-up on
; the mouse (just to be nice). If this is a normal termination, we leave
; it up to the child to save/restore the mouse state.
test fFaultAbort,0FFh
jz normal_exit
; Check if the mouse driver callback function has been set, and
; reset the mouse driver if so.
mov ax,word ptr lpfnUserMouseHandler
or ax,word ptr lpfnUserMouseHandler+2
jz @F
xor ax,ax
int 33h
@@:
; Check if the PS/2 Pointing Device Handler Address has been set and
; disable it if so.
ifndef NEC_98
mov ax,word ptr lpfnUserPointingHandler
or ax,word ptr lpfnUserPointingHandler+2
jz @f
mov ax,0C200h
xor bh,bh
int 15h
@@:
endif ;!NEC_98
; Hmmm, we have HP mouse code in dxhpbios.asm, but no clean up here...
normal_exit:
; Release the extended memory heap.
; call ReleaseXmemHeap
; Release the space being used for the descriptor tables and
; the protected mode code segment.
;
; If we have allocated an extended memory block, then free it.
; If we have allocated the HMA, then free it.
;
mov dx,hmemDOSX
or dx,dx
jz @F
xmssvc 0Dh
xmssvc 0Ah
@@:
cmp fUsingHMA,0
je @F
xmssvc 2
@@:
; Clean up after real mode code (and possible real mode incomplete
; initialization) -- restore real mode interrupt vectors.
chtm90:
RealModeCleanUp:
; Disable A20 if it was left enabled (normally 1 on 386 systems, 0 on 286)
mov cx,A20EnableCount
jcxz A20Okay
@@: xmssvc 6
loop @b
A20Okay:
; Restore the MSW EM bit (Emulate Math coprocessor) to its initial state
ifndef WOW_x86
inc fEMbit ;if fEMbit = FF, we never got far 'nuff to
jz @f ; change it
dec fEMbit
smsw ax
test al,01h ;in V86 mode?
jnz @f ; can't do the lmsw if so
or al,fEMbit
lmsw ax
@@:
endif
; Make sure DOS knows that the DOS extender is the current process
mov bx,segPSP
dossvc 50h
; Reenable a friendly EMM driver if we disabled it at startup
call EMMEnable
; Restore real mode interrupt vectors
push ds
lds dx,PrevInt2FHandler ;Int 2Fh handler
assume ds:NOTHING
mov ax,ds ;may not have gotten far enough to
or ax,dx ; set interrupt vectors, so make
jz @f ; sure before resotring.
mov ax,252Fh
int 21h
@@:
pop ds
assume ds:DGROUP
; We have cleaned up after ourselves, so now we can quit.
mov ax,WIN386_EXIT ;use Win/386 exit Int 2Fh to tell any
mov dx,WIN386_DOSX ; interested parties that we are
int 2Fh ; terminating
mov al,ExitCode ;exit the extender with either the exit
cmp al,0FFH ; status from the child, or a status
jnz @f ; that we have forced
dossvc 4Dh ;get child exit status if we haven't forced it
@@:
ifdef NEC_98
push ax
push es ; Dec IN_BIOS(0:456)
mov ax, 0040h
mov es, ax
test byte ptr es:[0], 20h ; check suspend/redume
jz @f
dec byte ptr es:[056h] ; for Y55
@@:
pop es
pop ax
endif ;NEC_98
dossvc 4Ch ;say goodnight Gracy...
; -------------------------------------------------------
; ChildTerminationHandler --
; Input: none
; Output: none
; Errors: none
; Uses:
assume ds:NOTHING,es:NOTHING,ss:NOTHING
public ChildTerminationHandler
ChildTerminationHandler:
sub sp,4 ; room for far ret
push ds
push es
pusha
mov si,ss
mov di,sp
mov ds,selDgroup
mov es,selDgroup
mov ss,selDgroup ;make sure we know where the
mov sp,offset DGROUP:rgwStack ; stack is when we get here
assume ds:DGROUP,es:DGROUP
;bugbug less than zero?
dec cDPMIClients
; free xmem allocated to this client
SwitchToProtectedMode
mov dx, selPspChild
FBOP BOP_DPMI,TerminateApp,FastBop
test DpmiFlags,DPMI_32BIT
jz cth05
;
; Return the stack frame used by the Wow32Intr16 interrupt handler
;
add pbReflStack,CB_STKFRAME
cth05: cmp cDPMIClients,0
jne cth10
;
; Reset the exception stack pointer to indicate free'd memory
;
mov selEHStack,0
;
; Give back the xms memory
;
FCLI
call ReInitIdt
push 0
pop es
call ReInitGdt
FBOP BOP_DPMI,DpmiNoLongerInUse,FastBop
cth10:
SwitchToRealMode
;bugbug put resource cleanup code here
cmp cDPMIClients,0
jne cth20
cth20: mov ax,[SegCurrentHostData]
mov es,ax
mov ax,es:[HdSegParent]
mov [SegCurrentHostData],ax
mov ax,es:[HdSelParent]
mov [SelCurrentHostData],ax
mov ax,es:[HdPSPParent]
mov SelPSPChild,ax
mov ax,word ptr es:[HdPspTerminate + 2]
mov bx,word ptr es:[HdPspTerminate]
mov cx,segPSPChild
mov ds,cx
assume ds:nothing
;
; Restore termination vector (app may think it knows what's here)
;
mov ds:[0ah],bx
mov ds:[0ch],ax
xor cx,cx
mov ds,cx
;
; Restore int 22 vector (terminate) Just in case
;
mov ds:[22h * 4],bx
mov ds:[22h * 4 + 2],ax
mov es,si
mov es:[di+20],bx
mov es:[di+22],ax
mov ss,si
mov sp,di
popa
pop es
pop ds
retf
; -------------------------------------------------------
; DisplayErrorMsg -- Display an error message on the screen. We set the
; video adapter to a text mode so the msg is visable (and gets rid
; of any bizarre mode that others may have set (like WIN.COM)).
;
; Note: This routine can be executed in real OR protected mode, so
; don't do anything mode specific--keep is short and sweet.
;
; Input: AX - offset of msg to display
; DX - segment of msg to display
; Output: None.
; Uses: AX, DX modified, all else preserved
assume ds:NOTHING, es:NOTHING
public DisplayErrorMsg
DisplayErrorMsg proc far
push ds ;save current DS
push ax ;save msg offset
; Set a text mode (normally 3, but possibly 7)
ifdef NEC_98
mov ah,41h ;
int 18h
mov ah,0Ch ;
int 18h
else ;!NEC_98
mov ax,0003h ;set video mode 3
int 10h
mov ah,0Fh ;get video mode
int 10h
cmp al,03h ;did we change to 3?
jz @f
mov ax,0007h ;no, must be mode 7
int 10h
@@:
endif ;!NEC_98
; Display the msg
mov ds,dx
pop dx
dossvc 9
pop ds
ret
DisplayErrorMsg endp
; -------------------------------------------------------
; DetermineFreeMemory -- Determine how much memory is free
;
; Input: none
; Output: bx = #paragraphs free memory
; Uses: bx
;
assume ds:dgroup,es:nothing
public DetermineFreeMemory
DetermineFreeMemory proc near
push ax
mov bx,0ffffh ; allocate all of memory
dossvc 48h
jnc @f
pop ax
ret
;bugbug report error
@@: mov bx,0ffffh
pop ax
ret
DetermineFreeMemory endp
EndLowSegment
DXPMCODE segment
assume cs:DXPMCODE
;--------------------------------------------------------
; ReInitIdt -- Set Idt entries back to default values
;
; Input: none
; Output: none
; uses: none
;
assume ds:dgroup,es:nothing
public ReInitIdt
ReInitIdt proc near
push bx
push cx
push dx
push si
push di
push es
mov ax,SEL_IDT OR STD_RING
mov es,ax
; Fill the IDT with interrupt gates that point to the fault handler and
; interrupt reflector entry vector.
xor di,di
mov dx,offset DXPMCODE:PmIntrEntryVector
mov cx,256
iidt23: mov es:[di].offDest,dx
mov es:[di].selDest,SEL_DXPMCODE or STD_RING
mov es:[di].cwParam,0
mov es:[di].arbGate,STD_TRAP ; BUGBUG- int gates not set up
mov es:[di].rsvdGate,0
add dx,5
add di,8
loop iidt23
; Now, fix up the ones that don't point to the interrupt reflector.
IFDEF WOW_x86
mov es:[1h*8].offDest,offset PMIntrIgnore
mov es:[3h*8].offDest,offset PMIntrIgnore
ifdef NEC_98
mov es:[11h*8].offDest,offset PMIntr11dummy
mov es:[18h*8].offDest,offset PMIntrVideo
mov es:[1ah*8].offDest,offset PMIntrPrinter
mov es:[1bh*8].offDest,offset PMIntr13
mov es:[1ch*8].offDest,offset PMIntrCalTi
mov es:[1dh*8].offDest,offset PMIntrGraph
mov es:[1fh*8].offDest,offset PMIntrMisc
else ;!NEC_98
mov es:[10h*8].offDest,offset PMIntrVideo
mov es:[13h*8].offDest,offset PMIntr13
mov es:[15h*8].offDest,offset PMIntrMisc
mov es:[19h*8].offDest,offset PMIntr19
endif ;!NEC_98
ENDIF
mov es:[21h*8].offDest,offset DXPMCODE:PMIntrDos
mov es:[25h*8].offDest,offset DXPMCODE:PMIntr25
mov es:[26h*8].offDest,offset DXPMCODE:PMIntr26
mov es:[28h*8].offDest,offset DXPMCODE:PMIntr28
mov es:[30h*8].offDest,offset DXPMCODE:PMIntrIgnore
mov es:[31h*8].offDest,offset DXPMCODE:PMIntr31
mov es:[33h*8].offDest,offset DXPMCODE:PMIntrMouse
mov es:[41h*8].offDest,offset DXPMCODE:PMIntrIgnore
ifndef WOW_x86
mov es:[4Bh*8].offDest,offset DXPMCODE:PMIntr4B
ifdef NEC_98
; Sound BIOS Int D2h handler
mov es:[0D2h*8].offDest,offset DXPMCODE:PMIntrSound
; extended DOS Int DCh handler (KANA/KANJI)
mov es:[0DCh*8].offDest,offset DXPMCODE:PMIntrExDos
endif ;!NEC_98
endif
;
; Set up the IDT, and dpmi32 state
;
mov ax,es ; Idt selector
mov bx,VDM_INT_16
DPMIBOP InitIDT
mov ax,5 ; handler increment
mov cx,SEL_DXPMCODE OR STD_RING
mov dx,offset DXPMCODE:PmFaultEntryVector
DPMIBOP InitExceptionHandlers
IFDEF WOW_x86
; make the stacks 16 bit again
cCall NSetSegmentAccess,<selDgroupPM,STD_DATA>
cCall NSetSegmentAccess,<selEHStack,STD_DATA>
ENDIF
; All done
iidt90: pop es
pop di
pop si
pop dx
pop cx
pop bx
ret
ReInitIdt endp
assume ds:DGROUP,es:NOTHING
public ReInitGdt
ReInitGdt proc near
push ax
push cx
push di
mov ax,selGDT ; LDT selector
lsl cx,ax ; LDT size
mov di,SEL_USER and SELECTOR_INDEX
DPMIBOP InitLDT
pop di
pop cx
pop ax
ret
ReInitGdt endp
;--------------------------------------------------------
; AllocateExceptionStack -- Get space for exception handler
;
; Input: none
; Output: none
; carry set on error
; uses: AX, BX, CX, DX, SI, DI
;
assume ds:dgroup,es:nothing
public AllocateExceptionStack
AllocateExceptionStack proc near
cmp selEHStack, 0 ;have we allocated one already
jnz aes_ok ;yes, return no carry
xor bx,bx
mov dx,bx
mov cx,1000h ;length of block
mov ax, 501h
push ds
FBOP BOP_DPMI, Int31Call, FastBop
jc @F
mov ax, SEL_USER_STACK or STD_RING
mov selEHStack,ax
cCall NSetSegmentDscr,<ax,bx,cx,0,0fffh,STD_DATA>
mov ax,selEHStack
mov cx,1000h ;reload length
dec cx
and cx,0fffeh ; Make sure SP is WORD aligned
mov npEHStackLimit,cx
;; mark the stack with 0DEADh
mov bx, cx
push ds
mov ds,ax
sub bx,2
mov word ptr [bx],0DEADh
pop ds
mov npEHStacklet, bx
push es
mov ax, selEHStack
mov es, ax
mov bx, npEHStackLimit
DPMIBOP InitPmStackInfo
pop es
aes_ok:
clc
@@:
ret
AllocateExceptionStack endp
DXPMCODE ends
;****************************************************************
end start