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windows-nt/Source/XPSP1/NT/base/mvdm/dpmi/dxboot.asm

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2020-09-26 03:20:57 -05:00
PAGE ,132
TITLE DXBOOT.ASM -- Dos Extender Startup Code
; Copyright (c) Microsoft Corporation 1988-1991. All Rights Reserved.
;****************************************************************
;* *
;* DXBOOT.ASM - Dos Extender Startup Code *
;* *
;****************************************************************
;* *
;* Module Description: *
;* *
;* This module contains real mode initialization code that *
;* initializes the dos extender itself. This includes *
;* allocating and initializing the descriptor tables, and *
;* relocating the dos extender for protected mode operation. *
;* *
;****************************************************************
;* Revision History: *
;* *
;* 01/29/92 mattfe Build for MIPS *
;* 12/19/90 amitc NetHeapSize default made 4k from 8k *
;* 12/03/90 amitc Added support for 'Win30CommDriver' switch *
; in system.ini *
;* 10/09/90 earleh split LDT from GDT and reduced XMS handles *
;* needed to boot program to 1 *
;* 08/08/90 earleh DOSX and client privilege ring determined *
;* by equate in pmdefs.inc *
;* 05/07/90 jimmat Started VCPI related changes. *
;* 04/09/90 jimmat Detect if on 286 & 287 installed. *
;* 04/02/90 jimmat Added PM Int 70h handler. *
;* 09/27/89 jimmat Changes to use FindFile to locate child *
;* program. *
;* 08/29/89 jimmat Now hooks real mode Int 2Fh chain. *
;* 08/20/89 jimmat Removed A20 code since HIMEM version 2.07 *
;* now works properly across processor resets. *
;* 07/28/89 jimmat Int PM Int 30h & 41h to be ignored, not *
;* reflected to real mode. *
;* 07/14/89 jimmat Added call to EMMDisable *
;* 06/16/89 jimmat Ifdef'd combined DOSX/child .EXE code *
;* 05/22/89 jimmat Added Int 13h/25h/26h/67h hooks. *
;* 05/18/89 jimmat Added setting of real mode Int 30h hook. *
;* 03/31/89 jimmat Added Priv Level to selectors during *
;* relocation and removed some dead code. *
;* 03/15/89 jimmat Added INT 31h hook *
;* 03/11/89 jimmat Added support for TSS & LDT & ring 1 *
;* 03/07/89 jimmat Converted to use WDEB386 debugger *
;* 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 handling code during init. *
;* 02/14/89 (GeneA): added initialization of INT15h vector, *
;* and changed segment limit of BIOS_CODE segment to *
;* 64k. *
;* 02/14/89 (GeneA): added code to copy protected mode code *
;* segment up into extended memory. Also code to allocate *
;* and copy GDT and IDT in extended memory. *
;* 01/31/89 (GeneA): reorganization of code. This module now *
;* contains only code for initializing the Dos Extender *
;* itself. *
;* 01/25/89 (GeneA): moved code for loading and relocating *
;* the child program here from dxinit.asm *
;* 01/24/89 (Genea): removed routines for hooking into real *
;* mode int 2Fh. (part of removing real mode int 2Fh *
;* interface from the dos extender). *
;* 12/13/88 (GeneA): created by moving code from DXINIT.ASM *
;* *
;****************************************************************
.286p
.287
; -------------------------------------------------------
; INCLUDE FILE DEFINITIONS
; -------------------------------------------------------
.xlist
.sall
include segdefs.inc
include gendefs.inc
include pmdefs.inc
include dpmi.inc
ifdef WOW_x86
include vdmtib.inc
endif
include intmac.inc
include dbgsvc.inc
.list
; -------------------------------------------------------
; GENERAL SYMBOL DEFINITIONS
; -------------------------------------------------------
;
; This structure defines the format of the EXE file header.
EXEHDR struc
idExeFile dw ? ;magic number to identify EXE file
cbLastPage dw ? ;number of bytes in last page of the file
crgbFileLen dw ? ;number of 512 byte pages in the file
clpRelocLen dw ? ;number of relocation entries in the table
cparHdrSize dw ? ;number of 16 byte paragraphs in header
cparMinAlloc dw ?
cparMaxAlloc dw ?
segStackInit dw ? ;initial stack segment
offStackInit dw ? ;initial stack pointer
wCheckSum dw ?
offCodeInit dw ? ;initial program counter
segCodeInit dw ? ;initial code segment
wRelocOffset dw ? ;byte offset of relocation table
idOverlay dw ? ;overlay number
EXEHDR ends
;
; This structure defines the parameter block to the XMS driver block
; move function.
XMSMOVE struc
cbxmsLen dd ? ;length of memory block
hxmsSource dw ? ;XMS source block handle
oxmsSource dd ? ;source offset
hxmsDest dw ? ;XMS destination block handle
oxmsDest dd ? ;destination offset
XMSMOVE ends
NOP_OPCODE equ 090h ; NO-OP opcode
IRET_OPCODE equ 0CFh ; IRET opcode
FAR_JMP_OPCODE equ 0EAh ; JMP FAR opcode
SHORT_JMP_OPCODE equ 0EBh ; JMP SHORT opcode
; -------------------------------------------------------
; EXTERNAL SYMBOL DEFINITIONS
; -------------------------------------------------------
extrn PMIntr31:NEAR
extrn PMIntr13:NEAR
extrn PMIntr19: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
extrn ReadINIFile:NEAR
ifdef NEC_98 ;
extrn PMIntrSound:NEAR ; for Sound Bios
extrn PMIntrExDos:NEAR ; for Extend Dos Function
extrn PMIntr11dummy:NEAR
extrn PMIntrPrinter:NEAR
extrn PMIntrCalTi:NEAR
extrn PMIntrGraph:NEAR
endif ;NEC_98 ;
extrn EMMDisable:NEAR
extrn FindFIle:NEAR
ifdef WOW_x86
extrn NpxExceptionHandler:near
extrn EndNpxExceptionHandler:near
endif
extrn RmUnsimulateProc:FAR
extrn PmUnsimulateProc:FAR
extrn PMFaultHandlerIRET:NEAR
extrn PMFaultHandlerIRETD:NEAR
extrn PMIntHandlerIRET:NEAR
extrn PMIntHandlerIRETD:NEAR
extrn PMDosxIret:NEAR
extrn PMDosxIretd:NEAR
extrn RMCallBackBop:FAR
extrn RMtoPMReflector:FAR
extrn RmSaveRestoreState:far
extrn PmSaveRestoreState:far
extrn RmRawModeSwitch:far
extrn PmRawModeSwitch:far
extrn DPMI_MsDos_API:far
extrn VCD_PM_Svc_Call:far
extrn XmsControl:far
extrn HungAppExit:far
DXPMCODE segment
extrn CodeEndPM:NEAR
externFP NSetSegmentDscr
DXPMCODE ends
; -------------------------------------------------------
; DATA SEGMENT DEFINITIONS
; -------------------------------------------------------
DXDATA segment
extrn selGDT:WORD
extrn segGDT:WORD
extrn selIDT:WORD
extrn segIDT:WORD
extrn bpGDT:FWORD
extrn bpIDT:FWORD
extrn sysTSS:WORD
extrn segPSP:WORD
extrn selPSP:WORD
extrn hmemDOSX:WORD
extrn f286_287:BYTE
extrn bpRmIVT:FWORD
extrn fhExeFile:WORD
extrn idCpuType:WORD
extrn cdscGDTMax:WORD
extrn rgbXfrBuf0:BYTE
extrn rgbXfrBuf1:BYTE
extrn clpRelocItem:WORD
extrn plpRelocItem:WORD
extrn lpfnXMSFunc:DWORD
ifdef NEC_98 ;
extrn fPCH98:BYTE ; PC-H98 flag
extrn fNHmode:BYTE ; NHmode flag
endif ;NEC_98 ;
extrn lpfnUserMouseHandler:DWORD
extrn fUsingHMA:BYTE
ifdef WOW_x86
extrn rgwWowStack:word
extrn FastBop:fword
endif
extrn pbHwIntrStack:word
IFNDEF WOW_x86
extrn IretBopTable:BYTE
ENDIF
public fDebug
fDebug db 0
szModName db 'DOSX',0 ;Our module name for use by WDEB386
if DEBUG
public lpchFileName
lpchFileName dd ?
endif
INIFileName db 'SYSTEM.INI',0 ;.INI file to read
public NetHeapSize, Int28Filter
INIKeywords label byte
db '[standard]',0
db 'netheapsize',0
NetHeapSize dw 4 ;default is 8k
db 'int28filter',0
Int28Filter dw 10 ;default is every 10th
if DEBUG ;------------------------------------------------------------
public fTraceDOS
db 'tracedos',0
fTraceDOS dw 0
public fTraceFault
db 'tracefault',0
fTraceFault dw 0
public fTraceA20
db 'tracea20',0
fTraceA20 dw 1
public TrapDOS
db 'trapdos',0
TrapDOS dw 0
db 'tableslow',0
fTablesLow dw 0
public fTraceReflect
db 'tracereflect',0
fTraceReflect dw 0
public fTraceMode
db 'tracemode',0
fTraceMode dw 0
endif ;DEBUG --------------------------------------------------------
db 0
szExeExtension db '.exe',0
; The following set of variables are used when copying our Pmode data
; structures into a HIMEM-allocated block.
public lmaIDT,lmaGDT,lmaDXPMCODE
CBIDTOFF = 0
CBGDTOFF = CDSCIDTDEFAULT * 8
IFNDEF WOW_x86
CBDXPMCODEOFF = CBGDTOFF + GDT_SIZE
ELSE
;
; Since we have no GDT for wow, we do not need space for it.
;
CBDXPMCODEOFF = CBGDTOFF
ENDIF
CBTABLESIZE = CBDXPMCODEOFF
.errnz CBIDTOFF and 0fh
.errnz CBGDTOFF and 0fh
.errnz CBDXPMCODEOFF and 0fh
lmaIDT dd CBIDTOFF
lmaGDT dd CBGDTOFF
lmaDXPMCODE dd CBDXPMCODEOFF
lmaLDT dd CBDXPMCODEOFF
extrn rgwStack:WORD
DXDATA ends
DXSTACK segment
extrn ResetStack:WORD
DXSTACK ends
; -------------------------------------------------------
page
; -------------------------------------------------------
; CODE SEGMENT VARIABLES
; -------------------------------------------------------
DXCODE segment
;************************************************************************
;
; REMEMBER... any code segment variables defined in this file
; will be discarded after initialization.
;
;************************************************************************
extrn CodeEnd:NEAR
extrn segDXCode:WORD
extrn segDXData:WORD
extrn selDgroup:WORD
ErrMsg MACRO name
extrn ER_&name:BYTE
ERC_&name equ offset ER_&name
ENDM
ErrMsg CPUTYPE
ErrMsg DXINIT
ErrMsg PROTMODE
ErrMsg NOHIMEM
ErrMsg EXTMEM
ErrMsg NOEXE
extrn RMInt2FHandler:NEAR
extrn PrevInt2FHandler:DWORD
szWinKernel db 'krnl386.exe',0
lpfnPrevXMS dd 0
DXCODE ends
DXPMCODE segment
extrn selDgroupPM:WORD
extrn segDXCodePM:WORD
extrn segDXDataPM:WORD
DXPMCODE ends
; -------------------------------------------------------
page
DXCODE segment
assume cs:DXCODE
; -------------------------------------------------------
; MAIN INITIALIZATION ROUTINES
; -------------------------------------------------------
; InitDosExtender -- This routine is the executive
; for initializing the dos extender.
;
; Input: none
; Output: various global tables and variables initialized.
; Dos Extender relocated for protected mode execution
; and moved into extended memory.
; Errors: returns CY set if error occurs, pointer to error message
; in DX
; Uses:
assume ds:DGROUP,es:DGROUP,ss:NOTHING
public InitDosExtender
InitDosExtender:
; Init the key code & data segment variables.
mov ax,cs
mov segDXCode,ax
mov ax,ds
mov segDXData,ax
mov selDgroup,ax
push es
mov ax,seg DXPMCODE
mov es,ax
assume es:DXPMCODE
mov selDgroupPM,SEL_DXDATA or STD_RING
mov segDXCodePM,cs
mov segDXDataPM,ds
pop es
assume es:DGROUP
; Do an initial shrink of our program memory. This assumes that DXPMCODE
; is the last segment in program.
mov bx,(offset DXPMCODE:CodeEndPM) + 10h
shr bx,4
add bx,seg DXPMCODE
sub bx,segPSP
mov es,segPSP
dossvc 4Ah
push ds
pop es
; Determine the type of CPU we are running on and make sure it is
; at least an 80286.
call CheckCPUType
cmp ax,2
jae indx14
mov ax,ERC_CPUTYPE
jmp indx80
indx14:
; If running on a 286, see if there is a 287 coprocessor installed
ifdef NEC_98 ;
;------------------- 90/08/15 --------------------
;check N/H at system area BIOS_FLAG(0:501h)
;if H mode, fNHmode bit on.
push es
push ax
mov ax,0
mov es,ax
test byte ptr es:[501h],8h ;if Hmode
jz not_Hmode
mov fNHmode,0FFh ;Now! Running on Hmode!!! 90/07/07
not_Hmode:
pop ax
pop es
;------------------- 90/08/15 --------------------
; If running on a 286, see if there is a 287 coprocessor installed
cmp al,2 ;286 processor?
jnz EMM_Disable
test fNHmode,0FFh
jz Copro_Nmode
;----- 90/07/04 in -----
; check co-processor exist at memory-switch
;----------------- Hmode -----------------
push ds
push bx
;;;;;;;; mov bx,0Eh
mov bx,0E000h ;90/10/04 bug
mov ds,bx
mov bx,3FEAh
mov al,byte ptr ds:[bx]
pop bx
pop ds
test al,08h ;0=none,1=exists
jmp Coprocessor
Copro_Nmode:
;----------------- Nmode -----------------
push ds
push bx
;;;;;;;; mov bx,0Ah
mov bx,0A000h ;90/10/04 bug
mov ds,bx
mov bx,3FEAh
mov al,byte ptr ds:[bx]
pop bx
pop ds
test al,08h ;0=none,1=exists
Coprocessor:
jz EMM_Disable
inc f286_287 ; yup, 286 & 287
EMM_Disable:
else ;NEC_98 ;
cmp al,2 ;286 processor?
jnz @f
int 11h ;math coprocessor installed?
test al,2
jz @f
ifndef WOW_x86
inc f286_287 ; yup, 286 & 287
endif
@@:
endif ;NEC_98 ;
; If on a 386 or greater, try to disable the EMM drivers we know about
call EMMDisable
; Check if the machine is already running in protected mode. If so, we
; can't run.
ifndef WOW_x86
smsw ax
test ax,1 ;check the protected mode bit
jz @f
mov ax,ERC_PROTMODE
jmp indx80
endif
@@:
; Get the full pathname of our EXE file, it's needed in a couple of places
call GetExeName
jnc @F
mov ax,ERC_DXINIT
jmp indx80
@@:
; Determine if the real mode Int 28h vector points anywhere. If it doesn't
; then we don't need to reflect Int 28h calls from protected to real mode.
; The user can still override this by putting a Int28Filter= entry in
; SYSTEM.INI.
push es
mov ax,3528h
int 21h
assume es:NOTHING
cmp byte ptr es:[bx],IRET_OPCODE ;Int 28h -> IRET?
jne @f
mov Int28Filter,0 ; yes, don't need to reflect
@@:
pop es
assume es:DGROUP
; Read SYSTEM.INI for any parameter overrides - NOTE: requires GetExeName
; having been run first!
mov bx,offset INIKeywords
mov dx,offset INIFileName
call ReadINIFile
; Check that the HIMEM.SYS driver is installed so that we can use it
; for extended memory management.
call SetupHimemDriver
jnc @F ; Himem is OK.
mov ax,ERC_NOHIMEM
jmp indx80
@@:
ifdef NEC_98 ;
push es
xor ax, ax
mov es, ax
test byte ptr es:[458h], 80h ; if NESA
jz not_MC
mov fPCH98, 0FFh ; it's a NPC NESA
not_MC:
pop es
assume es:DGROUP
endif ;NEC_98 ;
; Hook the real mode int vectors
mov ax,352Fh ;get previous Int 2Fh vector
int 21h
assume es:NOTHING
mov word ptr [PrevInt2FHandler],bx
mov word ptr [PrevInt2FHandler+2],es
push ds
pop es
assume es:DGROUP
mov ax,cs ;point to our rMode Int 2Fh
mov ds,ax
assume ds:NOTHING
mov dx,offset DXCODE:RMInt2FHandler
mov ax,252Fh
int 21h
push es
pop ds
assume ds:DGROUP
; Allocate and initialize the descriptor tables and TSS.
cCall AllocateExtMem
jnc indx20
mov ax,ERC_EXTMEM
jmp indx80
indx20:
push es
push bx
push dx
push di
push si
;
; Bop to initialize 32 bit support.
;
mov di, sp ;original stack offset
push SEL_DXPMCODE OR STD_RING
push offset DXPMCODE:HungAppExit
push SEL_DXPMCODE OR STD_RING
push offset DXPMCODE:XmsControl
push SEL_DXPMCODE OR STD_RING
push offset DXPMCODE:DPMI_MsDos_API
push SEL_DXPMCODE OR STD_RING
push offset DXPMCODE:VCD_PM_Svc_Call
push SEL_DXPMCODE OR STD_RING
push offset DXPMCODE:PmRawModeSwitch
push segDXCode
push offset DXCODE:RmRawModeSwitch
push SEL_DXPMCODE OR STD_RING
push offset DXPMCODE:PmSaveRestoreState
push segDXCode
push offset DXCODE:RmSaveRestoreState
mov bx,cdscGDTMax
shl bx,3
dec bx
push bx ;Initial LDT size
push selGDT
push SEL_DXPMCODE OR STD_RING ;pm reflector seg
push segDXCode
push offset DXCODE:RMtoPMReflector
push segDXCode
push offset DXCODE:RMCallBackBop
push SEL_DXPMCODE OR STD_RING
push offset DXPMCODE:PMDosxIretd
push SEL_DXPMCODE OR STD_RING
push offset DXPMCODE:PMDosxIret
push SEL_DXPMCODE OR STD_RING
push offset DXPMCODE:PMIntHandlerIRETD
push SEL_DXPMCODE OR STD_RING
push offset DXPMCODE:PMIntHandlerIRET
push SEL_DXPMCODE OR STD_RING
push offset DXPMCODE:PMFaultHandlerIRETD
push SEL_DXPMCODE OR STD_RING
push offset DXPMCODE:PMFaultHandlerIRET
push SEL_DXCODE OR STD_RING
push segDXCode
push SEL_DXPMCODE OR STD_RING
push offset DXPMCODE:PmUnsimulateProc
push segDXCode
push offset DXCODE:RmUnsimulateProc
push word ptr CB_STKFRAME
push segDXData
mov si,sp ;pass stack offset
DPMIBOP InitDosxRM
mov sp, di ;restore stack
ifdef WOW_x86
mov word ptr [FastBop],bx
mov word ptr [FastBop + 2],dx
mov word ptr [FastBop + 4],es
endif
pop si
pop di
pop dx
pop bx
pop es
call InitGlobalDscrTable ;set up the GDT
call SendDbgNotification ;tell NTSD about our segments
call InitIntrDscrTable ;set up the IDT
ifndef WOW_x86 ;bugbug
call InitTaskStateSeg ;set up the TSS
endif
if DEBUG
; DOSX is written such that it does not require any segment fix ups for
; protected mode operation. This wasn't always the case, and it's easy
; to make create dependencies so the routine CheckDOSXFixUps exists in
; the debug version to check for segment fix ups in non-initialization
; code.
call CheckDOSXFixUps
jnc @F
mov ax,ERC_DXINIT
jmp short indx80
@@:
endif ;DEBUG
; Move the Extended memory segment up into extended memory.
mov dx,seg DXPMCODE
call MoveDosExtender
jc indx80
; Move the GDT and IDT up into extended memory.
call MoveDscrTables
; Parse the command line, and locate the child exe file
call ParseCommandLine
IFNDEF WHEN_COMMAND_COM_WORKS
if WINDOWS ;--------------------------------------------------------
; If this is a Windows specific version of DOSX, we only run one child EXE
; (krnl?86.exe).
push ds
push cs
pop ds
assume ds:NOTHING
mov si,offset DXCODE:szWinKernel
mov di,offset RELOC_BUFFER
call strcpy
pop ds
assume ds:DGROUP
endif ;WINDOWS -------------------------------------------------
call FindFile ;setup done by ParseCommandLine
jnc indx70
mov ax,ERC_NOEXE
jmp short indx80
indx70:
ENDIF
; Initialized okay!
clc
jmp short indx90
; Error occured. Free any extended memory blocks allocated and then
; return the error code.
indx80: push ax ;save the error code
;
; 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
@@:
indxEXIT:
pop ax ;restore the error code
stc ;set error flag
indx90: ret
; -------------------------------------------------------
; AllocateExtMem -- Allocates memory used by DOSX for
; system tables and protected mode
; code.
; Allocates a temporary buffer in
; DOS memory for building the
; IDT and GDT.
; Input: none
; Output: none
; Uses: Flags
; Error: Carry set if cannot allocate memory.
;
; History:
; 10/05/90 - earleh wrote it
assume ds:DGROUP,es:NOTHING,ss:NOTHING
cProc AllocateExtMem,<PUBLIC,NEAR>,<ax,bx,dx>
cBegin
; If there is sufficient XMS memory, increase the size of the GDT/LDT
; up to the max of 8k selectors.
add word ptr lmaLDT,offset DXPMCODE:CodeEndPM
adc word ptr lmaLDT+2,0
add word ptr lmaLDT,0Fh ;make sure LDT is para aligned
adc word ptr lmaLDT+2,0
and word ptr lmaLDT,0FFF0h
@@:
xmssvc 08h ;Query Free Extended memory
cmp dx,1024 ;is there more than 1 meg available?
jb @f
mov cdscGDTMax,CDSCMAXLDT ; yes, max out the GDT size
@@:
mov ax,cdscGDTMax
xor dx,dx
shl ax,3
adc dx,0
add ax,word ptr lmaLDT
adc dx,word ptr lmaLDT+2
add ax,1023d
adc dx,0 ; DX:AX = total extended memory needed
shl dx,6
shr ax,10d
or dx,ax ; DX = kbytes needed
mov si,dx ; SI = kbytes needed
xmssvc 09h ; allocate the XMS block
or ax,ax
jz axm_error
mov hmemDOSX,dx
xmssvc 0Ch ; lock it, DX:BX = address
or ax,ax
jz axm_error
axm_address:
add word ptr lmaIDT,bx ; relocate tables & Pmode code
adc word ptr lmaIDT+2,dx
add word ptr lmaGDT,bx
adc word ptr lmaGDT+2,dx
add word ptr lmaDXPMCODE,bx
adc word ptr lmaDXPMCODE+2,dx
add word ptr lmaLDT,bx
adc word ptr lmaLDT+2,dx
mov bx,(CDSCIDTDEFAULT + GDT_SELECTORS + 1) shr 1
dossvc 48h ; get a DOS block for building tables
jc axm_error ; abort if error
mov segIDT,ax
mov selIDT,ax
add ax,CDSCIDTDEFAULT shr 1
mov segGDT,ax
mov selGDT,ax
clc
jmp axm_exit
axm_error:
stc
axm_exit:
cEnd
; -------------------------------------------------------
; SetupHimemDriver -- This routine checks that an XMS driver
; is installed and sets up for calling it.
;
; Input: none
; Output: none
; Errors: returns CY set if no driver available
; Uses: AX, all other registers preserved
assume ds:DGROUP,es:DGROUP,ss:NOTHING
public SetupHimemDriver
SetupHimemDriver proc near
push bx
push es
; Check to see if there is an XMS driver resident.
mov ax,4300h
int 2Fh
cmp al,80h
jnz sthd80
; There is an XMS driver resident, so init for calling it.
mov ax,4310h
int 2Fh
mov word ptr [lpfnXMSFunc],bx
mov word ptr [lpfnXMSFunc+2],es
; Make sure this is the proper XMS/driver version
xmssvc 0 ;returns XMS vers in ax, driver vers in bx
cmp ax,300h ;assume okay if XMS 3.0 or above
jae @f
cmp ax,200h ;require at least XMS 2.00
jb sthd80
cmp bx,21Ch ;if XMS 2.x, require driver version 2.28+
jb sthd80 ; (himem used to have minor vers in decimal)
@@:
; Verify that the XMS driver's A20 functions work
xmssvc 5 ;local enable
or ax,ax
jz sthd80
xmssvc 7 ;query A20
push ax
xmssvc 6 ;local disable
or ax,ax
pop ax ;recover query status
jz sthd80
or ax,ax ;should be NZ, (A20 enabled status)
jz sthd80
; Looks good to me...
clc
jmp short sthd90
; No XMS driver resident or wrong version or we couldn't enable A20.
sthd80: stc
sthd90: pop es
pop bx
ret
SetupHimemDriver endp
; -------------------------------------------------------
; MoveDosExtender -- This routine will move the Dos Extender
; protected mode segment up into extended memory.
; The himem driver function for moving memory blocks is used.
; The parameter block for this function is built in rgbXfrBuf0.
;
; Input: DX - real mode segment address of the segment to move
; Output: none
; Errors: returns CY set if error, Error code in AX
; Uses: AX used, all else preserved
; modifies rgbXfrBuf0
assume ds:DGROUP,es:NOTHING,ss:NOTHING
public MoveDosExtender
MoveDosExtender proc near
push bx
push cx
push dx
push si
cmp fUsingHMA,0
je mvdx40
;
; Our extended memory block is actually the HMA. Enable A20 and do
; the move ourselves.
;
xmssvc 5 ;local enable
push di
push ds
push es
mov cx,offset DXPMCODE:CodeEndPM
inc cx
and cx,0FFFEh
mov di,CBDXPMCODEOFF+10h
xor si,si
dec si
mov es,si
inc si
mov ds,dx
assume ds:NOTHING
;
; DS:SI = segIDT:0
; ES:DI = 0FFFF:CBDXPMCODEOFF+10h
; CX = code size
;
cld
rep movsb
pop es
assume ds:DGROUP
pop ds
pop di
xmssvc 6 ;local disable
jmp mvdx65
mvdx40:
; Move the data up into extended memory using the XMS driver's function.
mov si,offset DGROUP:rgbXfrBuf0
mov cx,offset DXPMCODE:CodeEndPM
inc cx
and cx,0FFFEh
mov word ptr [si].cbxmsLen,cx
mov word ptr [si].oxmsSource+2,dx ;real mode code segment address
mov ax,hmemDOSX
mov word ptr [si].hxmsDest,ax
xor ax,ax
mov word ptr [si].cbxmsLen+2,ax
mov [si].hxmsSource,ax
mov word ptr [si].oxmsSource,ax
mov word ptr [si].oxmsDest,CBDXPMCODEOFF
mov word ptr [si].oxmsDest+2,ax
xmssvc 0Bh
mvdx65:
clc
jmp short mvdx90
; Error occured
mvdx80: stc
mvdx90: pop si
pop dx
pop cx
pop bx
ret
MoveDosExtender endp
; -------------------------------------------------------
; MoveDscrTables -- This routine will move the GDT
; and IDT up into extended memory. The himem driver
; function for moving memory blocks is used. The parameter
; block for this function is built in rgbXfrBuf0.
;
; Input: none
; Output: none
; Errors: returns CY set if error occurs. Error code in AX
; Uses: AX, all else preserved
; modifies rgbXfrBuf0
assume ds:DGROUP,es:NOTHING,ss:NOTHING
public MoveDscrTables
MoveDscrTables proc near
push bx
push si
push es
cmp fUsingHMA,0
je @F
;
; Our extended memory block is actually the HMA. Enable A20 and do
; the move ourselves.
;
xmssvc 5 ;local enable
push ds
push di
push cx
mov cx,CBTABLESIZE
mov di,10h
xor si,si
dec si
mov es,si
inc si
mov ds,segIDT
assume ds:NOTHING
;
; DS:SI = segIDT:0
; ES:DI = 0FFFF:10
; CX = tables size
;
cld
rep movsb
pop cx
pop di
pop ds
assume ds:DGROUP
xmssvc 6 ;local disable
clc
jmp mvdt_ret
@@:
; Move the GDT and IDT together.
mov si,offset DGROUP:rgbXfrBuf0
mov word ptr [si].cbxmsLen,CBTABLESIZE
mov word ptr [si].cbxmsLen+2,0
mov ax,segIDT
mov word ptr [si].oxmsSource+2,ax
mov ax,hmemDOSX
mov word ptr [si].hxmsDest,ax
xor ax,ax
mov [si].hxmsSource,ax
mov word ptr [si].oxmsSource,ax
mov word ptr [si].oxmsDest,ax
mov word ptr [si].oxmsDest+2,ax
xmssvc 0Bh
IFDEF WOW
;
; Move the initialized selectors from the gdt to the ldt
;
mov word ptr [si].cbxmsLen,GDT_SIZE
mov word ptr [si].cbxmsLen+2,0
mov ax,segGDT
mov word ptr [si].oxmsSource+2,ax
mov ax,hmemDOSX
mov word ptr [si].hxmsDest,ax
xor ax,ax
mov word ptr [si].hxmsSource,ax
mov word ptr [si].oxmsSource,ax
mov word ptr [si].oxmsDest+2,ax
mov word ptr [si].oxmsDest,CBTABLESIZE + offset DXPMCODE:CodeEndPM
xmssvc 0Bh
ENDIF
mvdt_ret:
mov es,segIDT ;free the low memory copy
dossvc 49h
pop es
pop si
pop bx
ret
MoveDscrTables endp
; -------------------------------------------------------
; Send Debugger Notification
SendDbgNotification proc near
IFDEF WOW
;
; Send load notification to the debugger for DXDATA
;
push 1 ; data
push ds ; exe name
push offset EXEC_DXNAME
push ds ; module name
push offset szModName
push 0
push SEL_DXDATA OR STD_RING
push DBG_SEGLOAD
BOP BOP_DEBUGGER
add sp,16
;
; Send load notification to the debugger for DXCODE
;
push 0 ; code
push ds ; exe name
push offset EXEC_DXNAME
push ds ; module name
push offset szModName
push 1
push SEL_DXCODE OR STD_RING
push DBG_SEGLOAD
BOP BOP_DEBUGGER
add sp,16
;
; Send load notification to the debugger
;
push 0 ; code
push ds ; exe name
push offset EXEC_DXNAME
push ds ; module name
push offset szModName
push 2
push SEL_DXPMCODE OR STD_RING
push DBG_SEGLOAD
BOP BOP_DEBUGGER
add sp,16
ENDIF
ret
SendDbgNotification endp
; -------------------------------------------------------
; InitGlobalDscrTable -- This function will allocate a memory
; buffer from DOS and then initialize it as a global
; descriptor table. It will also initialize all global
; variables associated with GDT management.
; Descriptors in the range 0 - SEL_USER are given statically
; defined meanings. Descriptors from SEL_USER up are defined
; dynamically when a program is loaded or when dynamic memory
; management calls occur.
;
; NOTE: This routine works in real mode. The buffer where
; the GDT is built is in low memory.
;
; Input: AX - number of descriptors to initialize
; Output: none
; Errors: CY set if unable to obtain memory for the GDT
; Uses: AX used, all other registers preserved
; bpGDT initialized.
assume ds:DGROUP,es:DGROUP,ss:NOTHING
public InitGlobalDscrTable
InitGlobalDscrTable proc near
push bx
push cx
push dx
push di
push es
mov word ptr [bpGDT+0],GDT_SIZE - 1
mov ax,word ptr lmaGDT
mov word ptr [bpGDT+2],ax
mov ax,word ptr lmaGDT+2
mov word ptr [bpGDT+4],ax
;
; Start by initializing the GDT to 0.
;
mov cx,GDT_SIZE shr 1
mov es,segGDT
assume es:NOTHING
xor ax,ax
mov di,ax
rep stosw
; Next, initialize the statically defined descriptors.
;
; Set up a descriptor for our protected mode code.
xor ax,ax ;AX = 0
mov dx,cs ;our code segment paragraph address
call B_ParaToLinear ;convert to linear byte address
mov cx,offset CodeEnd
cCall NSetSegmentDscr,<SEL_DXCODE,bx,dx,ax,cx,STD_CODE>
; Set up another one, but ring 0 this time. Limit should be 0FFFFh
; or 386 reset to real mode will not work properly.
mov cx,0FFFFh
cCall NSetSegmentDscr,<SEL_DXCODE0,bx,dx,ax,cx,ARB_CODE0>
;
; Set up one for the other segment, and a Ring 0 alias.
;
mov cx,offset CodeEndPM
mov bx,word ptr lmaDXPMCODE
mov dx,word ptr lmaDXPMCODE+2
cCall NSetSegmentDscr,<SEL_DXPMCODE,dx,bx,0,cx,STD_CODE>
cCall NSetSegmentDscr,<SEL_NBPMCODE,dx,bx,0,cx,STD_CODE>
ifndef WOW_x86
cCall NSetSegmentDscr,<SEL_EH,dx,bx,0,cx,EH_CODE>
else
cCall NSetSegmentDscr,<SEL_EH,dx,bx,0,cx,STD_CODE>
endif
mov cx,0FFFFh
; Set up a descriptor for our protected mode data and stack area.
mov dx,ds ;our data segment paragraph address
call B_ParaToLinear ;convert to linear byte address
cCall NSetSegmentDscr,<SEL_DXDATA,bx,dx,ax,cx,STD_DATA>
IFNDEF WOW_x86
; Set up descriptor for IRET HOOKS
push dx
push bx
add dx,offset IretBopTable
adc bx,0
cCall NSetSegmentDscr,<SEL_IRETHOOK,bx,dx,ax,cx,STD_CODE>
pop bx
pop dx
ELSE
; Set up descriptor for IRET HOOKS
push dx
push bx
add dx,offset FastBop
adc bx,0
cCall NSetSegmentDscr,<SEL_IRETHOOK,bx,dx,ax,cx,STD_CODE>
pop bx
pop dx
ENDIF
IFNDEF WOW_x86
; And another one of those for ring 0
cCall NSetSegmentDscr,<SEL_DXDATA0,bx,dx,ax,cx,ARB_DATA0>
ENDIF
;
; Set up descriptors pointing to our PSP and environment.
mov dx,segPSP ;segment address of the PSP
call B_ParaToLinear ;convert to linear byte address
cCall NSetSegmentDscr,<SEL_PSP,bx,dx,ax,cx,STD_DATA>
mov selPSP,SEL_PSP
;
push es
mov es,segPSP
assume es:PSPSEG
mov dx,segEnviron
call B_ParaToLinear
cCall NSetSegmentDscr,<SEL_ENVIRON,bx,dx,ax,7FFFH,STD_DATA>
pop es
assume es:nothing
; Set up a descriptor that points to the GDT.
mov dx,word ptr [bpGDT+2] ;get the GDT linear byte address
mov bx,word ptr [bpGDT+4]
mov cx,word ptr [bpGDT+0] ;get the GDT segment size
cCall NSetSegmentDscr,<SEL_GDT,bx,dx,ax,cx,STD_DATA>
; Set up a descriptor for the LDT and an LDT data alias.
mov cx,cdscGDTMax ;get count of descriptors
shl cx,3
dec cx
mov dx,word ptr lmaLDT
mov bx,word ptr lmaLDT+2
IFNDEF WOW_x86
cCall NSetSegmentDscr,<SEL_LDT,bx,dx,ax,cx,STD_LDT>
ENDIF
cCall NSetSegmentDscr,<SEL_LDT_ALIAS,bx,dx,ax,cx,STD_DATA>
; set up a readonly selector to the LDT for the wow kernel
cCall NSetSegmentDscr,<SEL_WOW_LDT,bx,dx,ax,cx,STD_DATA>
; Set up descriptors pointing to the BIOS code and data areas
mov cx,0FFFFH ; CX = 0FFFFH
cCall NSetSegmentDscr,<SEL_BIOSCODE,000fh,ax,ax,cx,STD_CODE>
mov dx,40h*16
cCall NSetSegmentDscr,<SEL_BIOSDATA,ax,dx,ax,cx,STD_DATA>
; Set up a descriptor pointing to the real mode interrupt vector table.
cCall NSetSegmentDscr,<SEL_RMIVT,ax,ax,ax,cx,STD_DATA>
IFNDEF WOW_x86
; Setup a selector and data alias for the TSS
mov dx,ds ;get base address of TSS
call B_ParaToLinear ; (it may not be para aligned)
add dx,offset DGROUP:sysTSS
adc bx,ax
mov cx,(TYPE TSS286) - 1
cCall NSetSegmentDscr,<SEL_TSS,bx,dx,ax,cx,STD_TSS>
cCall NSetSegmentDscr,<SEL_TSS_ALIAS,bx,dx,ax,cx,STD_DATA>
ENDIF
;
; Pass address of HwIntr stack, and form pointer to lockcount in
; VdmTib. This enables us to coordinate stack switching with
; the nt kernel and the monitor. These components will switch
; the stack on Hw Interrupt reflection, dosx will switch it
; back at iret.
;
push es
mov ax,SEL_DXDATA or STD_RING
mov es, ax
mov bx, pbHwIntrStack
DPMIBOP InitPmStackInfo
pop es
IFDEF WOW_x86
;
; Create a code selector for the NPX emulation exception handler
;
mov ax,offset EndNpxExceptionHandler
sub ax,offset NpxExceptionHandler
mov bx,offset DXPMCODE:NpxExceptionHandler
add bx,word ptr lmaDXPMCODE
mov dx,word ptr lmaDXPMCODE + 2
cCall NSetSegmentDscr,<SEL_NPXHDLR,dx,bx,0,ax,STD_CODE>
ENDIF
clc ;worked! make sure CY is clear
; All done
igdt90: pop es
pop di
pop dx
pop cx
pop bx
ret
InitGlobalDscrTable endp
; -------------------------------------------------------
; InitIntrDscrTable -- This function will initialize the
; specified memory buffer as an Interrupt Descriptor Table,
; and set up all of the control variables associated with
; the IDT.
;
; NOTE: This routine works in real mode. The buffer where
; the IDT is built is in low memory.
; NOTE: The InitGlobalDscrTable function must be called before
; this function can be called.
;
; Input: AX - number of descriptors to initialize
; Output: none
; Errors: CY set if unable to obtain the memory required
; Uses: AX, all other registers preserved
assume ds:DGROUP,es:DGROUP,ss:NOTHING
public InitIntrDscrTable
InitIntrDscrTable proc near
push bx
push cx
push dx
push si
push di
push es
ifndef WOW_x86
; Save the current pointer to the real mode interrupt vector table.
sidt fword ptr bpRmIVT
endif
mov es,selIDT
assume es:NOTHING
mov cx,256 ;number of descriptors in table
shl cx,3 ;convert to count of bytes
dec cx ;compute segment size limit
mov word ptr [bpIDT+0],cx
mov dx,word ptr lmaIDT
mov word ptr [bpIDT+2],dx
mov bx,word ptr lmaIDT+2
mov word ptr [bpIDT+4],bx
cCall NSetSegmentDscr,<SEL_IDT,bx,dx,0,cx,STD_DATA>
; 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.
; BUGBUG In dxstrt.asm, these are x86 ONLY.
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 ;
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
.286p
; All done
iidt90: pop es
pop di
pop si
pop dx
pop cx
pop bx
ret
InitIntrDscrTable endp
; -------------------------------------------------------
;
; InitTaskStateSeg -- This function initializes the
; TSS for the DOS Extender.
;
; Input: none
; Output: none
; Errors: returns CY if unable to allocate memory
; Uses: all registers preserved
assume ds:DGROUP,es:DGROUP,ss:NOTHING
public InitTaskStateSeg
InitTaskStateSeg proc near
push ax
push cx
push di
; As a start, zero out the TSS
xor al,al
mov cx,type TSS286
mov di,offset DGROUP:sysTSS
rep stosb
; Set the LDT selector
mov sysTSS.tss_ldt,SEL_LDT
; Set the ring 0 stack seg/pointer, we don't bother to set the others
; since nothing runs below DOSX's ring. Currently very little code runs
; ring 0 - just when switching between real/proteted modes.
mov sysTSS.tss_ss0,SEL_DXDATA0
mov sysTSS.tss_sp0,offset DGROUP:ResetStack
; That's all it takes
pop di
pop cx
pop ax
clc
ret
InitTaskStateSeg endp
; -------------------------------------------------------
; MISC. STARTUP ROUTINES
; -------------------------------------------------------
; *** CheckCPUType - Set global variable for CPU type
;
; This routine relies on Intel-approved code that takes advantage
; of the documented behavior of the high nibble of the flag word
; in the REAL MODE of the various processors. The MSB (bit 15)
; is always a one on the 8086 and 8088 and a zero on the 286 and
; 386. Bit 14 (NT flag) and bits 13/12 (IOPL bit field) are
; always zero on the 286, but can be set on the 386.
;
; For future compatibility of this test, it is strongly recommended
; that this specific instruction sequence be used. The exit codes
; can of course be changed to fit a particular need.
;
; CALLABLE FROM REAL MODE ONLY
;
; ENTRY: NONE
;
; EXIT: AX holds CPU type ( 0=8086,80186; 2=80286; 3=80386; 4=80486 )
;
; USES: AX, DS must point to DX data segment
; idCpuType initialized
;
; Modified: 07-31-90 Earleh added code from Kernel, originally
; supplied by Intel, to check for 80486. Added check
; for V86 mode just in case a Limulator or something
; is active.
;
assume ds:DGROUP,es:NOTHING,ss:NOTHING
public CheckCPUType
CheckCPUType proc near
.8086
pushf ; save flags during cpu test
pushf
pop ax ; flags to ax
and ax, 0fffh ; clear bits 12-15
push ax ; push immediate is bad op-code on 8086
npopf ; try to put that in the flags
pushf
pop ax ; look at what really went into flags
and ah,0f0h ; mask off high flag bits
cmp ah,0f0h ; Q: was high nibble all ones ?
mov ax, 0
jz cidx ; Y: 8086
.286p
smsw ax
test ax,1 ; Protected mode?
jnz cid386 ; V86! Gotta be at least a 386.
push 0f000h ; N: try to set the high bits
npopf ; ... in the flags
pushf
pop ax ; look at actual flags
and ah,0f0h ; Q: any high bits set ?
mov ax, 2 ; at least 286
jz cidx ; N: 80286 - exit w/ Z flag set
; Y: 80386 - Z flag reset
; 386 or 486? See if we can set the AC (Alignment check) bit in Eflags
; Need to insure stack is DWORD aligned for this to work properly
.386
cid386:
mov ax, 3
push cx
push ebx
mov cx,sp ; Assume stack aligned
and cx,0011b ; set "pop" count
sub sp,cx ; Move to DWORD aligned
pushfd ; save entry flags (DWORD)
push dword ptr 40000h ; AC bit
popfd
pushfd
pop ebx
popfd ; Recover entry flags (DWORD)
add sp,cx ; pop off alignment bytes
test ebx,40000h ; Did AC bit set?
pop ebx
pop cx
jz short cidx ; No, 386
.286p
inc ax ; At least 80486...
cidx:
mov idCpuType,ax ;store CPU type in global
npopf ; restore flags after cpu test
CheckCPUType endp
; -------------------------------------------------------
; B_ParaToLinear
;
; This function will convert a paragraph address in the lower
; megabyte of memory space into a linear address for use in
; a descriptor table. This is a local duplicate of the function
; ParaToLinear in DXUTIL.ASM. This is duplicated here to avoid
; having to make far calls to it during the initialization.
;
; Input: DX - paragraph address
; Output: DX - lower word of linear address
; BX - high word of linear address
; Errors: none
; Uses: DX, BX used, all else preserved
assume ds:NOTHING,es:NOTHING,ss:NOTHING
B_ParaToLinear proc near
xor bh,bh
mov bl,dh
shr bl,4
shl dx,4
ret
B_ParaToLinear endp
if DEBUG ;-------------------------------------------------------
; -------------------------------------------------------
; CheckDOSXFixUps -- This routine will check for segment fix ups
; in non-initialization code that need to be converted from
; a segment to selector.
;
; This routine works by opening the EXE file that we were
; loaded from and examining the relocation table.
;
; 10-09-90 Earleh modified so that references in initialization
; code are not edited.
;
; 11-12-90 JimMat renamed from RelocateDosExtender and it now
; only checks for fix ups in DEBUG version since all fix ups
; in post-initialization code have been removed.
;
; Input: none
; Output: none
; Errors: returns CY set if error occurs
; Uses: AX, all else preserved
; modifies lpchFileName
assume ds:DGROUP,es:NOTHING,ss:DGROUP
public CheckDOSXFixUps
CheckDOSXFixUps proc near
push bp
mov bp,sp
push bx
push dx
push si
push di
push es
; Find the path to our exe fie.
mov word ptr [lpchFileName],offset EXEC_DXNAME
mov word ptr [lpchFileName+2],ds
; Set up for reading the relocation table from the exe file.
call B_InitRelocBuffer
jc rldx90 ;get out if error
; Go down through the relocation table and for each fixup item,
; patch in our selector.
mov bx,segPSP
add bx,10h ;the relocation table items are relative
; to the initial load address of our program
; image which is immediately after the PSP
rldx40: call B_GetRelocationItem ;get next relocation table entry
jz rldx60 ;if end of table, get out
mov di,ax ;offset of relocation item
add dx,bx ;adjust relocation item segment for our load
; address
mov es,dx ;
;
; Do not fixup instructions in initialization code.
;
cmp dx,seg DXCODE
jne rldx41
cmp di,offset DXCODE:CodeEnd
jnc rldx40
rldx41:
cmp dx,seg DXPMCODE
jne rldx42
cmp di,offset DXPMCODE:CodeEndPM
jnc rldx40
rldx42:
mov ax,es:[di] ;get the current fixup contents
cmp ax,seg DXCODE ;is it the mixed mode segment?
jnz rldx44
extrn lCodeSegLoc:WORD
cmp di,offset DXCODE:lCodeSegLoc ;special far jmp to flush
jz rldx40 ; pre-fetch queue? ok if so.
; Shouldn't get here--tell developer he messed something up!
int 3 ;****************************************
mov word ptr es:[di],SEL_DXCODE or STD_RING
jmp short rldx40
rldx44: cmp ax,seg DXPMCODE ;is it the protected mode only segment
jnz rldx40
; Shouldn't get here--tell developer he messed something up!
int 3 ;****************************************
mov word ptr es:[di],SEL_DXPMCODE or STD_RING
jmp rldx40 ;and repeat for the next one
; We have gone through the entire relocation table, so close up the exe file
rldx60: mov bx,fhExeFile
dossvc 3Eh
;
clc
jmp short rldx90
;
; Error occured
rldx80: stc
;
; All done
rldx90: pop es
pop di
pop si
pop dx
pop bx
mov sp,bp
pop bp
ret
CheckDOSXFixUps endp
; -------------------------------------------------------
; B_InitRelocBuffer -- This routine will open the EXE
; file and initialize for reading the relocation table
; as part of relocating the program for protected mode
; execution.
;
; Input: lpchFileName - pointer to exe file name
; Output: none
; Errors: returns CY set if error occurs
; Uses: AX modified, all other registers preserved
; sets up static variables:
; clpRelocItem, plpRelocItem, fhExeFile
; modifies rgbXfrBuf1 at offset RELOC_BUFFER
assume ds:DGROUP,es:NOTHING,ss:NOTHING
public B_InitRelocBuffer
B_InitRelocBuffer proc near
push bx
push cx
push dx
push si
;
; Open the EXE file.
push ds
lds dx,lpchFileName
mov al,0
dossvc 3Dh ;attempt to open the exe file
pop ds
jc inrl80 ;get out if error occurs
;
mov fhExeFile,ax ;store the file handle
mov bx,ax ;file handle to BX also
; Read the EXE file header, so that we can get information about
; the relocation table.
mov dx,offset RELOC_BUFFER
mov si,dx
mov cx,32
dossvc 3Fh
jc inrl80 ;get out if error
cmp ax,32
jnz inrl80
;
; Get the important values from the exe file header.
cmp [si].idExeFile,5A4Dh ;make sure it is an EXE file
jnz inrl80
mov ax,[si].clpRelocLen ;number of relocation items
mov clpRelocItem,ax
mov plpRelocItem,0FFFFh ;init the pointer to the first one
; to a bogus value to force the initial
; buffer to be loaded
;
; Get the location of the relocation table, and move the file pointer
; to its start.
xor cx,cx
mov dx,[si].wRelocOffset
mov al,cl
dossvc 42h
jnc inrl90
;
; Error occured
inrl80: stc
;
; All done
inrl90: pop si
pop dx
pop cx
pop bx
ret
B_InitRelocBuffer endp
; -------------------------------------------------------
; B_GetRelocationItem -- This routine will return the next
; relocation table entry from the exe file being relocated.
;
; Input: none
; Output: AX - offset of relocation item pointer
; DX - segment of relocation item pointer
; Errors: returns ZR true if end of table and no more items
; Uses: AX, DX modified, all other registers preserved
assume ds:DGROUP,es:NOTHING,ss:NOTHING
public B_GetRelocationItem
B_GetRelocationItem proc near
push si
;
cmp clpRelocItem,0 ;are there any relocation items left?
jz gtrl90 ;get out if not
;
; Check if the buffer is empty. The buffer for the relocation table is
; at offset RELOC_BUFFER in the buffer rgbXfrBuf1, and is 512 bytes long.
cmp plpRelocItem,offset RELOC_BUFFER + 512
jc gtrl40
;
; The buffer is empty, so we need to read the next part of it in.
push cx
push bx
push dx
mov ax,clpRelocItem ;number of items left in file
shl ax,2 ;multiply by size of relocation item
jc gtrl22 ;check for overflow
cmp ax,512 ;check if bigger than the buffer
jc gtrl24
gtrl22: mov ax,512 ;use buffer size as size of transfer
gtrl24: mov cx,ax
mov dx,offset RELOC_BUFFER
mov plpRelocItem,dx ;pointer to next reloc item to return
mov bx,fhExeFile
dossvc 3Fh
pop dx
pop bx
jc gtrl28 ;if error occured
cmp ax,cx ;or, if we didn't get as much as we asked
jnz gtrl28 ; for, we have an error
pop cx
jmp short gtrl40
;
gtrl28: pop cx
stc
jmp short gtrl90
;
; Get the next relocation item from the buffer.
gtrl40: mov si,plpRelocItem
lods word ptr [si] ;get the offset part of the reloc item
mov dx,ax
lods word ptr [si] ;get the segment part of the reloc item
xchg dx,ax ;put offset in AX, and segment in DX
mov plpRelocItem,si ;store the updated pointer
dec clpRelocItem ;and bump the count down by 1
or si,si ;clear the zero flag
;
; All done.
gtrl90: pop si
ret
B_GetRelocationItem endp
endif ;DEBUG --------------------------------------------------------
; -------------------------------------------------------
; GetExeName -- This routine will put a copy of the complete
; path name to the dos extender's exe file. In a name
; buffer in rgbXfrBuf1.
;
; Input: none
; Output: EXEC_DXNAME buffer updated with complete pathname.
; Errors: returns CY set if environment not correctly built.
; Uses: all preserved
assume ds:DGROUP,es:DGROUP,ss:DGROUP
public GetExeName
GetExeName proc near
push ax
push si
push di
push ds
; The name of the current program is stored at the end of the environment
; table. There are two bytes of 0 to indicate end of table, a byte
; with a 1 in it followed by another byte of 0 and then the null terminated
; string with the current program name.
gtxe20: mov ds,segPSP
assume ds:PSPSEG
mov ds,segEnviron
assume ds:NOTHING
xor si,si
gtxe22: lods byte ptr [si] ;get next byte from environment
or al,al ;test if 0
jnz gtxe22 ;if not, keep looking
lods byte ptr [si] ;get next byte
or al,al ;see if it is 0 also
jnz gtxe22
; We have found the double 0 at the end of the environment. So
; we can now get the name. At the end of the environment is an
; argc, argv construct. (i.e. a word giving the count of strings
; followed by an array of strings). Under DOS, argc is always 1,
; so check that there is a word of 1 here. If not, this environment
; wasn't built correctly and we don't know what is here.
lods word ptr [si]
cmp ax,1
jnz gtxe80
; We have the pointer to the name, now copy it.
mov di,offset EXEC_DXNAME
call strcpy
clc
jmp short gtxe90
; We have an error.
gtxe80: stc ;set error condition flag
gtxe90: pop ds
pop di
pop si
pop ax
ret
GetExeName endp
; -------------------------------------------------------
; COMMAND LINE PARSING ROUTINES
; -------------------------------------------------------
; ParseCommandLine -- This function will examine the dos
; command line that caused the Dos Extender to be exec'd
; and determine what the user wants done. It will set
; up the various buffers required for the child program
; to be loaded.
;
; NOTE: the child exe file name read from the command line
; is placed in RELOC_BUFFER in the case where the child
; name is specified on the command line. This buffer is
; used later when reading the relocation table while
; performing the fixups on the child.
;
; Input: none
; Output: AL - 0 if empty command line, else non-zero
; parse buffers in rgbXfrBuf1 set up.
; Errors: none
; Uses: AX, all else preserved
assume ds:DGROUP,es:DGROUP,ss:NOTHING
public ParseCommandLine
ParseCommandLine proc near
push si
push di
push ds
mov ds,segPSP
assume ds:PSPSEG
mov si,81h ;pointer to command line in PSP
; Skip any white space in front of the child program name.
prsc12: lods byte ptr [si]
cmp al,' '
jz prsc12
dec si
; Copy the command line tail following the program name to the command
; line buffer for use when we load the child.
prsc40: push si ;save current point in parse
mov di,offset EXEC_CMNDLINE + 1
xor dl,dl ;count characters in command line tail
prsc42: lods byte ptr [si] ;get the next character
stos byte ptr [di] ;store it into the output buffer
cmp al,0Dh ;is it the end of the line?
jz prsc44
inc dl ;count the character
jmp prsc42
prsc44: mov es:[EXEC_CMNDLINE],dl ;store the character count
pop si ;restore the buffer pointer
; Now we want to set up the two default FCB's by letting DOS parse the
; first two parameters on the command line.
mov di,offset EXEC_FCB0
mov al,1
dossvc 29h
mov di,offset EXEC_FCB1
mov al,1
dossvc 29h
prsc90:
pop ds
pop di
pop si
ret
ParseCommandLine endp
; -------------------------------------------------------
; strcpy -- copy a null terminated string.
;
; Input: DS:SI - pointer to source string
; ES:DI - pointer to destination buffer
; Output: ES:DI - pointer to end of destination string
; Errors: none
; Uses: DI modified, all else preserved
assume ds:NOTHING,es:NOTHING,ss:NOTHING
public strcpy
strcpy proc near
push ax
push si
stcp10: lods byte ptr [si]
stos byte ptr [di]
or al,al
jnz stcp10
dec di
pop si
pop ax
ret
strcpy endp
; -------------------------------------------------------
; strcmpi -- This function will perform a case insensitive
; comparison of two null terminated strings.
;
; Input: DS:SI - string 1
; ES:DI - string 2
; Output: ZR if the strings match, else NZ
; CY set if string 1 less than string 2
; Errors: none
; Uses: all registers preserved
assume ds:NOTHING,es:NOTHING,ss:NOTHING
public strcmpi
strcmpi proc near
push si
push di
stcm20: mov al,byte ptr ds:[si]
call toupper
mov ah,al
mov al,byte ptr es:[di]
call toupper
cmp ah,al
jnz stcm90
or al,ah
jz stcm90
inc si
inc di
jmp stcm20
stcm90: pop di
pop si
ret
strcmpi endp
; -------------------------------------------------------
; IsFileNameChar -- This function will examine the
; character in AL and determine if it is a legal character
; in an MS-DOS file name.
;
; Input: AL - character to test
; Output: ZR true if character is legal in a file name
; Errors: none
; Uses: all registers preserved
assume ds:NOTHING,es:NOTHING,ss:NOTHING
IsFileNameChar proc near
push ax
cmp al,20h ;is it a control character
jbe isfc80 ;if so, it isn't valid
cmp al,':'
jz isfc80
cmp al,';'
jz isfc80
cmp al,','
jz isfc80
cmp al,'='
jz isfc80
cmp al,'+'
jz isfc80
cmp al,'<'
jz isfc80
cmp al,'>'
jz isfc80
cmp al,'|'
jz isfc80
cmp al,'/'
jz isfc80
cmp al,'"'
jz isfc80
cmp al,'['
jz isfc80
cmp al,']'
jz isfc80
xor al,al
jmp short isfc90
; Not a valid file name character
isfc80: or al,0FFh
isfc90: pop ax
ret
IsFileNameChar endp
; -------------------------------------------------------
; toupper -- This function will convert the character
; in AL into upper case.
;
; Input: AL - character to convert
; Output: AL - upper case character
; Errors: none
; Uses: AL modified, all else preserved
assume ds:NOTHING,es:NOTHING,ss:NOTHING
public toupper
toupper proc near
cmp al,'a'
jb toup90
cmp al,'z'
ja toup90
sub al,'a'-'A'
toup90:
ret
toupper endp
; -------------------------------------------------------
DXCODE ends
;
;****************************************************************
end
Reference in a new issue Copy permalink