OS/2 Shareware BBS: 10 Tools/10-Tools.zip/caway349.zip/SOURCE/ALL/CW32.ASM

Assembly Source File | 1999-12-30 | 99KB | 4,995 lines

;
;CauseWay v2 main file.
;
;
;Things to note:
;
;The IDT has a page to itself even though it only needs 2k. For RAW/VCPI systems
;the top 2k could be used for something else.
;
;Things to do:
;
;Put in some sort of system stack overflow checking and terminate the program
;if it happens.
;
    option oldstructs

    include general.inc
    include strucs.inc
    include cw.inc
;    include cw-undoc.inc

    ifndef ENGLISH
ENGLISH    equ    0
    endif
    ifndef SPANISH
SPANISH    equ    0
    endif

;=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
;
;Main code segment. This takes care of calling the right initialisation routines
;and generaly getting everything rolling.
;
_cwMain    segment para public 'Main thread' use16
    assume cs:_cwMain, ds:_cwMain, ss:_cwStack
;
;Want a copyright message embedded first.
;
Copyright    label byte
    db 'CauseWay DOS Extender v'
VersionMajor    db '3.'
VersionMinor    db '49'
    db " Copyright 1992-99 Michael Devore.",13,10,"All rights reserved.",13,10,0


    .386
;-------------------------------------------------------------------------------
;
;Final init stuff.
;
cwOpen    proc    near
    assume ds:nothing        ;make our data addresable.
    mov    ds,cs:DataSegment
    assume ds:_cwMain
    ;
    mov    d[TerminationHandler],offset cwClose
    mov    w[TerminationHandler+4],cs
;
;Now we know the machines details, re-size the program
;block again to release as much memory as possible.
;
    mov    edi,offset Int21Buffer
    push    ds
    pop    es
    mov    ax,RealPSPSegment
    mov    es:Real_ES[edi],ax
    mov    bx,_cwDPMIEMU
    cmp    ProtectedType,2
    jnz    @@KeepRaw
    mov    bx,_cwRaw
@@KeepRaw:    sub    bx,ax        ;Size program.
    inc    bx
    mov    TSRSize,bx
    mov    es:Real_EBX[edi],ebx
    mov    es:Real_EAX[edi],4a00h
    mov    bl,21h
    mov    ErrorNumber,1
    sys    IntXX
    test    es:w[edi+Real_Flags],1
    jnz    @@9
    mov    ErrorNumber,0    ;clear error number.
;
;Force accurate memory values.
;
    or    ecx,-1
    sys    GetMemLinear32
;
;Enable resource tracking and MCB allocations.
;
    or    ResourceTracking,-1    ;Enable resource tracking.
;
;Run the main program.
;
    mov    edx,offset MainExec    ;name to exec.
    mov    esi,80h
    mov    es,PSPSegment
    xor    cx,cx
    sys    cwExec        ;run the bugger.
    jnc    @@8
    add    ax,10-1        ;convert error number.
    mov    ErrorNumber,ax
    jmp    @@9
@@8:    cmp    DebugDump,0
    jnz    @@9
    mov    ErrorLevel,ax    ;store programs error level.
    mov    ErrorNumber,0    ;clear error number.
@@9:    jmp    cwClose
cwOpen    endp


;-------------------------------------------------------------------------------
;
;Shut everything down.
;
cwClose    proc    near

IFDEF DEBUG4
    push    eax
    push    ebx
    push    ecx
    push    edx
    push    ds
    push    cs
    pop    ds
    mov    edx,OFFSET debugatext1
debugaloop2:
    cmp    BYTE PTR ds:[edx],0
    je    debugab
    mov    ecx,1
    mov    bx,1
    mov    ah,40h
    int    21h
    inc    edx
    jmp    debugaloop2
debugab:
    mov    edx,OFFSET debugatext2
    push    cs
    pop    ds
    mov    ecx,2
    mov    bx,1
    mov    ah,40h
    int    21h
    pop    ds
    pop    edx
    pop    ecx
    pop    ebx
    pop    eax
    jmp    debugaout

debugatext1    DB    'Entering cwClose...',0
debugatext2    DB    13,10

debugaout:
    push    ecx
    mov    ecx,100000h
debugaloop:
;    dec    ecx
;    jne    debugaloop
    pop    ecx
ENDIF

    assume ds:nothing
    mov    ds,cs:DataSegment
    assume ds:_cwMain
    ;
    mov    ResourceTracking,0
    mov    mcbAllocations,0
    sti
    mov    w[TerminationHandler+4],0
    ;

IFDEF DEBUG4
    push    eax
    push    ebx
    push    ecx
    push    edx
    push    ds

    mov    dx,w[ExceptionExtension+12]
;    lar    ax,dx
    cmp    dx,127h
    jnz    debughout
;    and    ah,3
;    cmp    ah,3
;    jne    debughout

    push    cs
    pop    ds
    mov    edx,OFFSET debughtext1
debughloop2:
    cmp    BYTE PTR ds:[edx],0
    je    debughb
    mov    ecx,1
    mov    bx,1
    mov    ah,40h
    int    21h
    inc    edx
    jmp    debughloop2
debughb:
    mov    edx,OFFSET debughtext2
    push    cs
    pop    ds
    mov    ecx,2
    mov    bx,1
    mov    ah,40h
    int    21h
    pop    ds
    pop    edx
    pop    ecx
    pop    ebx
    pop    eax
    jmp    debughout

debughtext1    DB    'Calling DebugDisplay...',0
debughtext2    DB    13,10

debughout:
    push    ecx
    mov    ecx,100000h
debughloop:
;    dec    ecx
;    jne    debughloop
    pop    ecx

ENDIF

    push    cs
    push    offset @@dd0
    push    w[ExceptionExtension+12]
    mov    eax,offset DebugDisplay
    push    ax
    retf
@@dd0:    ;

    cmp    ErrorNumber,0
    jz    @@NoError

    mov    ax,ErrorNumber    ;Get the error number.
    xor    dx,dx
    mov    cx,10
    div    cx
    add    al,'0'
    mov    b[ErrorM00n],al
    add    dl,'0'
    mov    b[ErrorM00n+1],dl

    cmp    EnableDebugDump,0    ; if debug dump turned off, no screen i/o
    je    @@NoError

    xor    edx,edx
    mov    dx,w[ErrorList]
    mov    ah,9
    int    21h
;
;Get a pointer to the appropriate error message and print it.
;
    mov    bx,ErrorNumber
    add    bx,bx
    xor    edx,edx
    mov    dx,[ErrorList+bx]
    mov    ah,9
    int    21h
;
;Now exit with the error number as the DOS "errorlevel".
;
@@NoError:
;
;Remove extension patches.
;

IFDEF DEBUG4
    push    eax
    push    ebx
    push    ecx
    push    edx
    push    ds
    push    cs
    pop    ds
    mov    edx,OFFSET debugctext1
debugcloop2:
    cmp    BYTE PTR ds:[edx],0
    je    debugcb
    mov    ecx,1
    mov    bx,1
    mov    ah,40h
    int    21h
    inc    edx
    jmp    debugcloop2
debugcb:
    mov    edx,OFFSET debugctext2
    push    cs
    pop    ds
    mov    ecx,2
    mov    bx,1
    mov    ah,40h
    int    21h
    pop    ds
    pop    edx
    pop    ecx
    pop    ebx
    pop    eax
    jmp    debugcout

debugctext1    DB    'Removing interrupt patches...',0
debugctext2    DB    13,10

debugcout:
    push    ecx
    mov    ecx,100000h
debugcloop:
;    dec    ecx
;    jne    debugcloop
    pop    ecx
ENDIF

    mov    di,offset ExtensionList    ;list of interupt patches.
@@p1:    cmp    w[di+2],-1        ;search for the end of the table so we can restore
    jz    @@p0        ;vectors in reverse order.
    add    di,2
    jmp    @@p1
    ;
@@p0:    mov    bp,w[di]
    cmp    ds:w[bp+32],-1    ;installed?
    jnz    @@p2
    pushm    di,bp
    push    cs
    push    offset @@p3
    push    ds:w[bp+20]
    push    ds:w[bp+16]
    retf
@@p3:    popm    di,bp
@@p2:    sub    di,2
    cmp    di,offset ExtensionList-2
    jnz    @@p0
;
;Remove api exception patches.
;
    cmp    apiExcepPatched,0
    jz    @@pe0
    mov    ax,cs
    push    ax
    mov    ax,offset @@pe0
    push    ax
    mov    ax,apiCodeSeg
    push    ax
    mov    eax,offset UnPatchExc
    push    ax
    retf
@@pe0:    ;
;
;Remove the API patch.
;
    mov    es,apiDataSeg
    assume es:_apiCode
    test    SystemFlags,1
    jz    @@Use32
    mov    dx,es:w[OldIntSys]
    mov    cx,es:w[OldIntSys+2]
    jmp    @@Use0
@@Use32:    mov    edx,es:d[OldIntSys]
    mov    cx,es:w[OldIntSys+4]
@@Use0:    mov    bl,31h
    mov    ax,205h
    int    31h
    mov    es:d[cwIdentity],0
    mov    es:d[cwIdentity+4],0
    assume es:nothing
    ;
@@noAPI:
    cmp    ProtectedType,2    ;DPMI?
    jz    @@DPMI

IFDEF DEBUG4
    push    eax
    push    ebx
    push    ecx
    push    edx
    push    ds
    push    es
    mov    ax,KernalZero
    mov    es,ax
    mov    ebx,0b8000h
    mov    BYTE PTR es:[ebx],'1'
    push    cs
    pop    ds
    mov    ecx,OFFSET debugdtext1
debugdloop2:
    cmp    BYTE PTR ds:[ecx],0
    je    debugdb
    mov    dl,ds:[ecx]
    mov    ah,2
    int    21h
    inc    ecx
    jmp    debugdloop2
debugdb:
    mov    dl,13
    mov    ah,2
    int    21h
    mov    dl,10
    mov    ah,2
    int    21h
    pop    es
    pop    ds
    pop    edx
    pop    ecx
    pop    ebx
    pop    eax
    jmp    debugdout

debugdtext1    DB    'Making raw addressable...',0
debugdtext2    DB    13,10

debugdout:
    push    ecx
    mov    ecx,100000h
debugdloop:
    dec    ecx
    jne    debugdloop
    pop    ecx
ENDIF

;
;Make RAW stuff addressable.
;
    cli            ;Don't want interrupts interfering.
    mov    ax,KernalDS        ;Get supervisor data descriptor,
    mov    ds,ax        ;DS,ES,FS,GS,SS must be data with 64k limit
    assume ds:_cwRaw
    mov    ax,KernalZero
    mov    es,ax
;
;Switch to RAW exit code.
;
    push    _cwMain
    push    offset @@6
    mov    ax,KernalCS
    push    ax
    mov    ax,offset RawVCPIRealMode
    push    ax
    retf
@@6:    jmp    @@RealMode
;
;Remove DPMI stuff.
;
@@DPMI:

IFDEF DEBUG4
    push    eax
    push    ebx
    push    ecx
    push    edx
    push    ds
    push    cs
    pop    ds
    mov    ecx,OFFSET debugetext1
debugeloop2:
    cmp    BYTE PTR ds:[ecx],0
    je    debugeb
    mov    dl,ds:[ecx]
    mov    ah,2
    int    21h
    inc    ecx
    jmp    debugeloop2
debugeb:
    mov    dl,13
    mov    ah,2
    int    21h
    mov    dl,10
    mov    ah,2
    int    21h
    pop    ds
    pop    edx
    pop    ecx
    pop    ebx
    pop    eax
    jmp    debugeout

debugetext1    DB    'Removing DPMI setup...',0
debugetext2    DB    13,10

debugeout:
    push    ecx
    mov    ecx,100000h
debugeloop:
    dec    ecx
    jne    debugeloop
    pop    ecx
ENDIF

    assume ds:nothing
    mov    ds,cs:DataSegment
    assume ds:_cwMain

    if    0
    cmp    d[OldInt21hExec],0
    jz    @@d0
    mov    bl,21h
    mov    dx,w[OldInt21hExec]
    mov    cx,w[OldInt21hExec+2]
    mov    ax,201h
    int    31h
@@d0:    movzx    edx,dx
    endif

    jmp    @@InRealMode
;
;Make sure our data is addressable.
;
@@RealMode:    mov    ax,_cwMain
    mov    ds,ax
    assume ds:_cwMain
;
;Display the "CauseWay error: ??" bit.
;
@@InRealMode:

    if    0
    cmp    ErrorNumber,0
    jz    @@NoError

    push    ax
    mov    al,3
    call    bordm
    pop    ax

    mov    ax,ErrorNumber    ;Get the error number.
    xor    dx,dx
    mov    cx,10
    div    cx
    add    al,'0'
    mov    b[ErrorM00n],al
    add    dl,'0'
    mov    b[ErrorM00n+1],dl

    cmp    EnableDebugDump,0    ; if debug dump turned off, no screen i/o
    je    @@NoError

    xor    edx,edx
    mov    dx,w[ErrorList]
    mov    ah,9
    int    21h
;
;Get a pointer to the appropriate error message and print it.
;
    mov    bx,ErrorNumber
    add    bx,bx
    mov    dx,[ErrorList+bx]
    mov    ah,9
    int    21h
;
;Now exit with the error number as the DOS "errorlevel".
;
@@NoError:
    endif

; MED, 12/24/99, coalesce free memory by attempting to allocate largest possible
;  with upper memory in the chain
    mov    ax,5800h
    int    21h
    push    ax
    mov    ax,5802h
    int    21h
    push    ax
    mov    bx,1
    mov    ax,5803h
    int    21h
    mov    bx,81h
    mov    ax,5801h
    int    21h

    mov    ah,48h
    mov    bx,-1
    int    21h

    pop    bx
    mov    ax,5803h
    int    21h
    pop    bx
    mov    ax,5801h
    int    21h

    mov    ax,ErrorNumber
    or    ax,ax
    jnz    @@Exit
    mov    ax,ErrorLevel
@@Exit:

IFDEF DEBUG4
    push    eax
    push    ebx
    push    ecx
    push    edx
    push    ds
    push    cs
    pop    ds
    mov    edx,OFFSET debugbtext1
debugbloop2:
    cmp    BYTE PTR ds:[edx],0
    je    debugbb
    mov    ecx,1
    mov    bx,1
    mov    ah,40h
    int    21h
    inc    edx
    jmp    debugbloop2
debugbb:
    mov    edx,OFFSET debugbtext2
    push    cs
    pop    ds
    mov    ecx,2
    mov    bx,1
    mov    ah,40h
    int    21h
    pop    ds
    pop    edx
    pop    ecx
    pop    ebx
    pop    eax
    jmp    debugbout

debugbtext1    DB    'Performing final real mode 4ch termination...',0
debugbtext2    DB    13,10

debugbout:
    push    ecx
    mov    ecx,100000h
debugbloop:
    dec    ecx
    jne    debugbloop
    pop    ecx
ENDIF

    mov    ah,4ch
    int    21h
cwClose    endp


;-------------------------------------------------------------------------------
Int21hExecPatch proc    near
    assume ds:nothing
    pushf
    cmp    ax,4b00h
    jnz    @@Old

    inc    cs:Int21hExecCount

    popf
    pushf
    call    cs:d[OldInt21hExec]

    pushf
    push bp
    push ax
    mov bp,sp
    mov ax,[bp+2+2]
    and ax,1
;    and w[bp+2+2+2+2+2],1
    and w[bp+2+2+2+2+2],0fffeh    ; MED 01/24/96

    or w[bp+2+2+2+2+2],ax
    pop ax
    pop bp
    popf

    dec    cs:Int21hExecCount

    iret
@@Old:
    popf
    jmp    cs:d[OldInt21hExec]
OldInt21hExec    dd 0
    assume ds:_cwMain
Int21hExecCount db 0
Int21hExecPatch endp
    .386p


;-------------------------------------------------------------------------------
Bordm    proc    near
    pushm    ax,dx
    mov    ah,al
    mov    dx,3dah
    in    al,dx
    mov    dl,0c0h
    mov    al,11h
    out    dx,al
    mov    al,ah
    out    dx,al
    mov    al,20h
    out    dx,al
    popm    ax,dx
    ret
Bordm    endp

;-------------------------------------------------------------------------------
;
;Some global data.
;
RealPSPSegment    dw ?        ;Real mode PSP segment.
RealENVSegment    dw ?        ;Real mode environment segment.
ProtectedFlags    dw 0        ;Bit significant, 0-DPMI,1-VCPI,2-RAW.
ProtectedType    dw 0        ;0-RAW,1-VCPI,2-DPMI.
ProtectedForce    db 0
DOSVersion    dw 0
SystemFlags    dd 0
apiCodeSeg    dw 0
apiDataSeg    dw 0
;
CodeSegment    dw MainCS    ;Setup CS selector.
CodeSegmenti    dw InitCS
DataSegment    dw MainDS    ;Setup DS selector.
DataSegmenti    dw InitDS
StackSegment    dw MainSS
RealSegment    dw KernalZero
PSPSegment    dw MainPSP
ENVSegment    dw MainENV
BasePSP    dw 0
BasePSPAddress    dd 0
;
TSRSize    dw 0
;
ErrorNumber    dw 0
ErrorLevel    dw 0
ErrorList    dw ErrorM00,ErrorM01,ErrorM02,ErrorM03,ErrorM04,ErrorM05,ErrorM06,ErrorM07
    dw ErrorM08,ErrorM09,ErrorM10,ErrorM11,ErrorM12,ErrorM13,ErrorM14,ErrorM15
    dw ErrorM16
ErrorM00    db 'CauseWay error '
ErrorM00n    db '00 : $'
ErrorM01    label byte
    if ENGLISH
    db 'Unable to re-size program memory block.',13,10,'$'
    elseif SPANISH
    db "Incapaz de redimensionar el bloque de memoria del programa.",13,10,"$"
    endif
ErrorM02    db "$"
ErrorM03    db "$"
ErrorM04    db "$"
ErrorM05    label byte
    if ENGLISH
    db 'Not enough memory for CauseWay.',13,10,'$'
    elseif SPANISH
    db "Memoria insuficiente para CauseWay.",13,10,"$"
    endif
ErrorM06    db "$"
ErrorM07    db "$"
ErrorM08    db "$"
ErrorM09    label byte
    if ENGLISH
    db 'Unrecoverable exception. Program terminated.',13,10,'$'
    elseif SPANISH
    db "Excepcion irrecuperable. Programa terminado.",13,10,"$"
    endif
ErrorM10    label byte
    if ENGLISH
    db 'Unable to find '
ErrorM10_T    db 'application to load.',13,10,'$',32 dup (0)
    elseif SPANISH
    db "Incapaz de encontrar '
ErrorM10_T    db 'aplicacion a cargar.",13,10,"$",32 dup (0)
    endif
ErrorM11    label byte
    if ENGLISH
    db 'DOS reported an error or corrupt file found.'
    elseif SPANISH
    db "DOS informo de un error o de un fichero corrupto."
    endif
ErrorM11_0    db 13,10,'$'
    db "No:"
ErrorM11_1    db "00000000",13,10,"$"
ErrorM12    label byte
    if ENGLISH
    db 'Not enough memory to load application.',13,10,'$'
    elseif SPANISH
    db "Memoria insuficiente para cargar la aplicacion.",13,10,"$"
    endif
ErrorM13    db "$"
ErrorM14    label byte
    if ENGLISH
    db 'Memory structures destroyed. Program terminated.',13,10,'$'
    elseif SPANISH
    db "Estructuras de memoria destruidas. Programa terminado.",13,10,"$"
    endif
ErrorM15    label byte
    if ENGLISH
    db 'DOS reported an error while accessing swap file. Program terminated.',13,10,'$'
    elseif SPANISH
    db "DOS informa de un error mientras se accede al fichero de swap. Programa terminado.",13,10,"$"
    endif
ErrorM16    label byte
    if ENGLISH
    db "Unsupported DOS function call, program terminated.",13,10,"$"
    elseif SPANISH
    db "Llamada a funcion no soportada del DOS, programa terminado.",13,10,"$"
    endif
;
ALIGN 4
MainExec    db 128 dup (0)
;
DtaBuffer    db 128 dup (0)
;
TransferSize    dd 8192
TransferReal    dw ?
;
MouseETarget    dd 0,0
ResourceTracking dw 0
ForcedFind    dd 0,0
mcbAllocations    dw 0
LinearAddressCheck db 0
;
TerminationHandler dd offset InitError,InitCS
UserTermRoutine    DF    0
UserTermDump    DF    0    ; dump location for register info
;
DPMIStateAddr    df 0
DPMIStateSize    dd 0
DPMIStackOff    dw ?
DPMIStackSeg    dw ?
;
DebugDump    db 0
EnableDebugDump    DB    1
UserTermFlag    DB    0
Pad1Flag    DB    0

IFDEF PERMNOEX
NoEXECPatchFlag    DB    1
ELSE
NoEXECPatchFlag    DB    0
ENDIF

; MED, 11/11/99
; used to flag checking XMS total memory because EMM386 lies and acts as VCPI
;  host when NOVCPI set, but provides no memory
VCPIHasNoMem    DB    0

NewCWErrName    DB    81 DUP (0)
DOS4GFlag    db 0
;
;*** MED change for Michael Devore name
CopyCheck    label byte
    db 'C'-44,'a'-44,'u'-44,'s'-44,'e'-44,'W'-44,'a'-44,'y'-44,' '-44
    db 'D'-44,'O'-44,'S'-44,' '-44,'E'-44,'x'-44,'t'-44,'e'-44,'n'-44
    db 'd'-44,'e'-44,'r'-44,' '-44,'v'-44,255,255,255,255
    db ' '-44,'C'-44,'o'-44,'p'-44,'y'-44,'r'-44,'i'-44,'g'-44
    db 'h'-44,'t'-44,' '-44,'1'-44,'9'-44,'9'-44,'2'-44,'-'-44,'9'-44
    db '9'-44,' '-44,'M'-44
    db 'i'-44,'c'-44,'h'-44,'a'-44,'e'-44,'l'-44,' '-44,'D'-44,'e'-44
    db 'v'-44,'o'-44,'r'-44,'e'-44,'.'-44,13-44,10-44,'A'-44,'l'-44,'l'-44
    db ' '-44,'r'-44,'i'-44,'g'-44,'h'-44,'t'-44,'s'-44,' '-44,'r'-44
    db 'e'-44,'s'-44,'e'-44,'r'-44,'v'-44,'e'-44,'d'-44,'.'-44,13-44,10-44
CopyCount    dw 0
;
Int21Buffer    db size RealRegsStruc dup (?)
Int10Buffer    db size RealRegsStruc dup (?)
Int33Buffer    db size RealRegsStruc dup (?)
;
apiExcepPatched db 0
;
ExtensionList    label word
    dw ExceptionExtension
    dw Int21hExtension,Int10hExtension,Int33hExtension
    dw -1
;
ExceptionExtension dw _Excep,0
    dd offset ExcepEnd-ExcepStart
    dd offset ExcepOpen,?
    dd offset ExcepClose,?
    dd 0
    dd 0
    dd 0
;
Int21hExtension dw _Int21h,1        ;segment start.
    dd offset Int21hEnd-Int21hStart    ;segment length.
    dd offset Int21hOpen,?     ;init code.
    dd offset Int21hClose,?    ;remove code.
    dd 0            ;code selector.
    dd 0            ;data selector.
    dd 0            ;installed flag.
;
Int10hExtension dw _Int10h,1        ;segment start.
    dd offset Int10hEnd-Int10hStart    ;segment length.
    dd offset Int10hOpen,?    ;init code.
    dd offset Int10hClose,?    ;remove code.
    dd 0            ;code selector.
    dd 0            ;data selector.
    dd 0            ;installed flag.
;
Int33hExtension dw _Int33h,1        ;segment start.
    dd offset Int33hEnd-Int33hStart    ;segment length.
    dd offset Int33hOpen,?    ;init code.
    dd offset Int33hClose,?    ;remove code.
    dd 0            ;code selector.
    dd 0            ;data selector.
    dd 0            ;installed flag.
;
Temp0_    dd ?
Temp1_    dd ?
;
DebugUserOff    DD    ?
DebugUserSel    DW    ?
DebugUserCount    DW    0    ; must be initialized, nonzero value flags operation
DebugAsciiFlag    DB    ?
_cwMain    ends


;=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
;
;Default stack used during startup and exit.
;
_cwStack    segment para stack 'main stack' use16
    db 2048 dup (0)
_cwStackEnd    label byte
_cwStack    ends


    include raw&vcpi.asm

    include api.asm
    include exceptn.asm
    include int10h.asm
    include int21h.asm
    include int33h.asm


;=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
;
;The initialiseation code seg. Takes care of things like checking for the right
;processor and determining how we're going to get into protected mode.
;
_cwInit    segment para public 'init code' use16
    assume cs:_cwInit, ds:_cwMain

dpmiSelBuffer    db 8 dup (0)

;-------------------------------------------------------------------------------
Startup    proc    near
;
;Make global data addresable.
;
    mov    ax,_cwMain
    mov    ds,ax

; MED, 12/30/99
; works around weird bug in some machines due to Windows/hardware/BIOS??? error
;  where a CauseWay application in AUTOEXEC.BAT which uses DOS function 8
;  to get a keystroke when no other application in AUTOEXEC.BAT gets a
;  keystroke will cause failure in Windows 98 (and 95?) when opening a DOS
;  box after Windows startup.  Caused by A20 or keyboard port stabilization?
    mov    cx,127
kloop:
    mov    ax,0b00h
    int    21h
    test    al,al
    jne    done
    loop    kloop
done:

;
;Stow real mode PSP and environment values, we'll need them later.
;
    mov    RealPSPSegment,es
    mov    ax,es:w[02ch]
    mov    RealEnvSegment,ax    ;Stow ENV for later.
;
;Re-size memory so we can allocate what we want high.
;
    mov    cs:IErrorNumber,1
    mov    ax,es
    mov    bx,_cwEnd        ;Get program end segment.
    sub    bx,ax        ;Size program.
    inc    bx
    mov    ah,4ah
    int    21h        ;Re-size memory block.

; MED 06/16/97
;    jc    InitError
    jnc    chk386

toiniterr:
    jmp    InitError

;
;Check we're on at least a 386 system.
;
chk386:
    mov    cs:IErrorNumber,2
    call    CheckProcessor

;    jc    InitError
    jc    toiniterr

;
;Check DOS version is high enough.
;
    mov    cs:IErrorNumber,4
    call    CheckDOSVersion
    jc    InitError
;
;Get execution name from environment.
;
    call    GetEXECName
;
;Retrieve setup info from 3P header.
;
    call    GetSystemFlags
;
;Check if a suitable method for switching to protected mode exists.
;
    call    GetProtectedType
    mov    cs:IErrorNumber,3
    cmp    ProtectedFlags,0    ;Any types available?
    jz    InitError
;
;Get CAUSEWAY environment variable settings.
;
    call    GetENVStuff
;
;Decide which environment to use.
;
    call    SetProtectedType
;
;Move the DTA to where we can get at it in the future.
;
    mov    dx,offset DTABuffer
    mov    ah,1ah
    int    21h
;
;now see about type specific initialisations.
;
    cmp    ProtectedType,2    ;DPMI initialiseation?
    jz    @@InitDPMI
;
;Useing either RAW or VCPI so do the stuff that's common to both for now.
;
    mov    ax,_cwRaw
    mov    ds,ax
    assume ds:_cwRaw
;
;Get SDA address so VMM can change BREAK state.
;
    .386
    push    ds
    mov    ax,5d06h
    int    21h
    mov    ax,ds
    pop    ds
    add    si,17h
    movzx    eax,ax
    shl    eax,4
    movzx    esi,si
    add    eax,esi
    mov    BreakAddress,eax
;
;Find out if XMS is present.
;
    mov    ax,4300h        ;XMS install check.
    int    2fh
    cmp    al,80h        ;XMS present?
    jnz    @@NoXMS
;
;XMS detected so work out max block size and entry point.
;
    mov    ax,4310h        ;Get XMS API.
    int    2fh
    mov    w[XMSControl],bx
    mov    w[XMSControl+2],es
    mov    XMSPresent,1        ;flag XMS is available.

; MED, 09/10/99, support extended XMS API to calculate XMS available to CauseWay
;  (maximum of 2G-32K, i.e. 32 handles/entries of 64K-1)
    mov    ah,0
    call    d[XMSControl]    ; get info
    cmp    ah,3
    jb    xms2
    cmp    bh,3
    jb    xms2
    cmp    bl,8
    jb    xms2            ; treat early 3.x drivers < 3.08 as 2.x

; use extended XMS API
    mov    XMSVer3Present,1    ; flag XMS 3.x driver present
    mov    ah,88h
    call    d[XMSControl]    ;get size of biggest block free.
    mov    edx,eax
    test    eax,eax
    jz    @@YesXMS        ;no memory available.
    mov    cs:d[@@XMSSize],edx
    mov    ah,89h
    call    d[XMSControl]    ;claim biggest block to force XMS
    cmp    ax,1            ;to stake a claim on int 15h.
    jnz    @@YesXMS
    mov    cs:b[@@NumXMSHandles],1
    push    dx
    mov    ah,8eh
    call    d[XMSControl]    ; get handle information
    cmp    ax,1
    jnz    @@NoHandles3
    cmp    cx,4
    jc    @@NoHandles3
    sub    cx,2
    mov    cs:b[@@NumXMSHandles],32
    cmp    cx,32
    jnc    @@NoHandles3
    mov    cs:b[@@NumXMSHandles],cl    ; cx known 8-bit value

@@NoHandles3:
    pop    dx
    mov    ah,0ah
    call    d[XMSControl]    ;now free it.

    movzx    eax, BYTE PTR cs:[@@NumXMSHandles]
    mov    edx,eax
    shl    eax,16
    sub    eax,edx        ; eax == handles (up to 32) * 65535
    cmp    eax,cs:d[@@XMSSize]
    jae    @@ComputeSize
    mov    cs:d[@@XMSSize],eax    ; throttle maximum size

@@ComputeSize:
    push    eax
    xor    edx,edx
    movzx    ebx,BYTE PTR cs:[@@NumXMSHandles]
    div    ebx
    pop    ebx
    cmp    ax,4        ; eax known 16-bit value
    jnc    @@SizeOK3
    mov    ax,bx        ; ebx == maximum size, known 16-bit value here

@@SizeOK3:
    mov    XMSBlockSize,ax
    jmp    @@YesXMS

xms2:
    mov    ah,8
    call    d[XMSControl]    ;get size of biggest block free.
    mov    dx,ax
    or    ax,ax
    jz    @@YesXMS        ;no memory available.
    mov    cs:w[@@XMSSize],dx
    mov    ah,9
    call    d[XMSControl]    ;claim biggest block to force XMS
    cmp    ax,1        ;to stake a claim on int 15h.
    jnz    @@YesXMS
    mov    cs:b[@@NumXMSHandles],1
    push    dx
    mov    ah,0eh
    call    d[XMSControl]    ;now free it.
    cmp    ax,1
    jnz    @@NoHandles
    cmp    bl,4
    jc    @@NoHandles
    sub    bl,2
    mov    cs:b[@@NumXMSHandles],32
    cmp    bl,32
    jnc    @@NoHandles
    mov    cs:b[@@NumXMSHandles],bl
@@NoHandles:    pop    dx
    mov    ah,0ah
    call    d[XMSControl]    ;now free it.
    mov    ax,cs:w[@@XMSSize]
    push    ax
    xor    dx,dx
    xor    bh,bh
    mov    bl,cs:b[@@NumXMSHandles]
    div    bx
    pop    bx
    cmp    ax,4
    jnc    @@SizeOK
    mov    ax,bx
@@SizeOK:    mov    XMSBlockSize,ax
    jmp    @@YesXMS
;
;Install raw A20 handler.
;
@@NoXMS:    call    InstallA20
;
;Get A20 state.
;
@@YesXMS:    push    ds
    les    di,HighMemory    ;   with the four at FFFF:0090
    lds    si,LowMemory        ; Compare the four words at 0000:0080
    mov    cx,4
    cld
    repe  cmpsw
    pop    ds
    xor    ax,ax
    jcxz    @@A20OFF         ; Are the two areas the same?
    inc    ax            ; No, return A20 Enabled
@@A20OFF:    mov    A20Flag,al
;
;Change DOS allocation stratergy to highest so we'll get UMB's if available.
;
    mov    ax,5800h
    int    21h
    mov    cs:w[@@OldStrat],ax
    mov    ax,5802h
    int    21h
    mov    cs:w[@@OldStrat+2],ax
    mov    bx,1
    mov    ax,5803h
    int    21h
    mov    bx,81h
    mov    ax,5801h
    int    21h
;
;Grab memory for page dir, page alias & first page table entry.
;
    mov    bx,(4096*3)/16    ;smallest allocation possible.
    mov    ah,48h
    int    21h
    jc    @@OldWay
    push    ax
    movzx    eax,ax
    shl    eax,4        ;linear address.
    mov    ebx,eax
    add    eax,4095
    and    eax,0ffffffffh-4095    ;round up to next page.
    sub    eax,ebx
    shr    eax,4
    mov    bx,ax
    mov    cx,ax
    add    bx,(4096*3)/16
    mov    ah,4ah
    pop    es
    pushm    bx,cx,es
    int    21h        ;re-size the block.
    popm    bx,cx,es
    jnc    @@NewWay
    mov    ah,49h
    int    21h        ;release this block.
    ;
@@OldWay:    mov    cs:IErrorNumber,5
    mov    bx,(4096*4)/16    ;need space for 3 page tables on
    mov    ah,48h        ;4k boundary.
    int    21h
    jc    InitError
    mov    dx,ax
    movzx    eax,ax        ;get segment address.
    shl    eax,4        ;make linear.
    mov    ebx,eax
    add    eax,4095
    and    eax,0FFFFFFFFh-4095    ;round up to nearest page.
    mov    ecx,eax
    sub    ecx,ebx
    shr    ecx,4
    shr    eax,4        ;Get segment value again.
    jmp    @@GotSeg
    ;
@@NewWay:    mov    ax,es
    mov    dx,ax
    add    ax,cx        ;move to real start.
    ;
@@GotSeg:
    pushm    cx,dx
    mov    es,ax

; MED 09/19/96
;    mov    PageDirReal,ax    ;setup page directory address.
;    add    ax,4096/16
;    mov    Page1stReal,ax    ;setup 1st page table address.
    mov    Page1stReal,ax    ;setup 1st page table address.
    add    ax,4096/16
    mov    PageDirReal,ax    ;setup page directory address.

    add    ax,4096/16
    mov    PageAliasReal,ax    ;setup alias table address.
    xor    di,di
    mov    cx,4096*3
    xor    al,al
    cld
    rep    stosb        ;clear it.
    movzx    eax,PageDIRReal
    shl    eax,4
    mov    PageDIRLinear,eax
    mov    VCPI_CR3,eax
    movzx    eax,PageALIASReal
    shl    eax,4
    mov    PageAliasLinear,eax
    movzx    eax,Page1stReal
    shl    eax,4
    mov    Page1stLinear,eax
    popm    cx,dx
;
;See if enough wasted space to squeeze TSS into.
;
    cmp    cx,(((size TSSFields)+2+16)/16)
    jc    @@TSSOld
    mov    ax,dx           ;get segment.
    add    dx,(((size TSSFields)+2+16)/16)    ;move segment base.
    sub    cx,(((size TSSFields)+2+16)/16)    ;update space left size.
    jmp    @@TSSGot
;
;Allocate memory for Kernal TSS.
;
@@TSSOld:    mov    cs:IErrorNumber,5
    mov    bx,(((size TSSFields)+2+16)/16)    ;(4096/2)+2+16)/16
    mov    ah,48h
    int    21h
    jc    InitError
@@TSSGot:    mov    KernalTSSReal,ax
;
;See if enough wasted space to squeeze GDT into.
;
    cmp    cx,((8*GDT_Entries)/16)+1
    jc    @@GDTOld
    mov    ax,dx           ;get segment.
    add    dx,((8*GDT_Entries)/16)+1    ;move segment base.
    sub    cx,((8*GDT_Entries)/16)+1    ;update space left size.
    jmp    @@GDTGot
;
;Allocate some memory for the GDT.
;
@@GDTOld:    mov    cs:IErrorNumber,5
    mov    bx,((8*GDT_Entries)/16)+1
    mov    ah,48h
    int    21h
    jc    InitError
@@GDTGot:    mov    GDTReal,ax
    mov    es,ax
    movzx    eax,ax
    shl    eax,4
    mov    GDTLinear,eax
    xor    di,di
    mov    cx,(8*GDT_Entries)
    xor    al,al
    cld
    rep    stosb
;
;Allocate some memory for the stack.
;
    mov    cs:IErrorNumber,5
    mov    ebx,RawStackPos
    shr    ebx,4
    mov    ah,48h
    int    21h
    jc    InitError
    mov    RawStackReal,ax
    mov    es,ax
    mov    cx,w[RawStackPos]
    xor    di,di
    xor    al,al
    cld
    rep    stosb

; MED 09/19/96
; Set address for VMM page to disk buffer.
    mov    cs:IErrorNumber,5
    mov    bx,4096/16
    mov    ah,48h
    int    21h
    jc    InitError
    mov    PageBufferReal,ax
    movzx    eax,ax
    shl    eax,4
    mov    PageBufferLinear,eax

;
;Restore DOS memory allocation stratergy.
;
    mov    bx,cs:w[@@OldStrat+2]
    xor    bh,bh
    mov    ax,5803h
    int    21h
    mov    bx,cs:w[@@OldStrat]
    xor    bh,bh
    mov    ax,5801h
    int    21h
;
;Need to initialise 1st page table to map <1meg+64k 1:1.
;
    mov    es,Page1stReal
    xor    di,di
    mov    cx,256+16        ;1st 1 meg + 64k.
    mov    esi,111b        ;user+write+present
@@0:    mov    es:[di],esi
    add    di,4        ;next page table entry.
    add    esi,4096        ;next physical page address.
    dec    cx
    jnz    @@0

; MED 09/19/96
COMMENT !
;
;Set address for VMM page to disk buffer.
;
    mov    ax,PageDIRReal
    mov    PageBufferReal,ax
    movzx    eax,ax
    shl    eax,4
    mov    PageBufferLinear,eax
END COMMENT !

;
;Set address for DOS INT 21h PM to Real transfer buffer.
;

; MED 09/19/96
;    mov    bx,Page1stReal
    mov    bx,PageDirReal

    push    ds
    mov    ax,_cwMain
    mov    ds,ax
    assume ds:_cwMain
    mov    TransferReal,bx
    assume ds:_cwRaw
    pop    ds
;
;Allocate the GDT entries.
;
    mov    es,GDTReal
;
;Fill in the null entry just for the hell of it.
;
    xor    esi,esi        ;Null entry at 0.
    xor    ecx,ecx
    xor    ax,ax
    xor    di,di
    call    MakeDesc
;
;Fill in the VCPI entries so we don't try to use them later.
;
    xor    esi,esi
    xor    ecx,ecx
    mov    ah,DescPresent+DescPL3+DescMemory+DescRWData
    mov    di,VCPI_0
    call    MakeDesc
    xor    esi,esi
    xor    ecx,ecx
    mov    ah,DescPresent+DescPL3+DescMemory+DescRWData
    mov    di,VCPI_1
    call    MakeDesc
    xor    esi,esi
    xor    ecx,ecx
    mov    ah,DescPresent+DescPL3+DescMemory+DescRWData
    mov    di,VCPI_2
    call    MakeDesc
;
;Allocate 40h descriptor.
;
    mov    esi,400h
    mov    ecx,65535
    xor    al,al
    mov    ah,DescPresent+DescPL3+DescMemory+DescRWData
    mov    di,Kernal40h
    call    MakeDesc
;
;Allocate kernal task descriptors, TSS itself first.
;
    movzx    esi,KernalTSSReal
    shl    esi,4
    mov    ecx,size TSSFields+2
    xor    al,al
    mov    ah,DescPresent+DescPL3+Desc386Tss
    mov    di,KernalTS
    call    MakeDesc
;
;TSS PL0 stack.
;
    movzx    esi,KernalTSSReal
    shl    esi,4
    add    esi,tPL1Stack
    mov    ecx,65535
    mov    al,b[RawSystemFlags]
    xor    al,1
    shl    al,6
    mov    ah,DescPresent+DescPL0+DescMemory+DescRWData
    mov    di,KernalPL0
    call    MakeDesc
;
;Mode switch PL0 stack.
;
    movzx    esi,KernalTSSReal
    shl    esi,4
    add    esi,tPL1Stack
    mov    ecx,65535
    xor    al,al
    mov    ah,DescPresent+DescPL0+DescMemory+DescRWData
    mov    di,KernalSwitchPL0
    call    MakeDesc
;
;LDT
;
    xor    esi,esi
    xor    ecx,ecx
    xor    al,al
    mov    ah,DescPresent+DescPL3+DescLDT
    mov    di,KernalLDT
    call    MakeDesc
;
;Kernal (RAW) code seg.
;
    xor    esi,esi
    mov    si,_cwRaw
    shl    esi,4
    mov    ecx,65535
    xor    al,al
    mov    ah,DescPresent+DescPL3+DescMemory+DescERCode
    mov    di,KernalCS
    call    MakeDesc
;
;Kernal (RAW) code seg at PL0
;
    xor    esi,esi
    mov    si,_cwRaw
    shl    esi,4
    mov    ecx,65535
    xor    al,al
    mov    ah,DescPresent+DescPL0+DescMemory+DescERCode
    mov    di,KernalCS0
    call    MakeDesc
;
;Kernal (RAW) data seg.
;
    xor    esi,esi
    mov    si,_cwRaw
    shl    esi,4
    mov    ecx,65535
    xor    al,al
    mov    ah,DescPresent+DescPL3+DescMemory+DescRWData
    mov    di,KernalDS
    call    MakeDesc
;
;Kernal (RAW) stack seg.
;
    movzx    esi,RawStackReal
    shl    esi,4
    mov    ecx,65535
    mov    al,b[RawSystemFlags]
    xor    al,1
    shl    al,6
    mov    ah,DescPresent+DescPL3+DescMemory+DescRWData
    mov    di,KernalSS
    call    MakeDesc
;
;Kernal PL3 to PL0 call gate.
;
    xor    ecx,ecx
    mov    esi,KernalCS0
    xor    al,al
    mov    ah,DescPresent+DescPL3+Desc386Call
    mov    di,KernalPL3_2_PL0
    call    MakeDesc
;
;DPMI emulator code seg.
;
    xor    esi,esi
    mov    si,_cwDPMIEMU
    shl    esi,4
    mov    ecx,offset cwDPMIEMUEnd-cwDPMIEMUStart
    mov    al,1 shl 6
    mov    ah,DescPresent+DescPL3+DescMemory+DescERCode
    mov    di,DpmiEmuCS
    call    MakeDesc
;
;DPMI emulator code seg at PL0
;
    xor    esi,esi
    mov    si,_cwDPMIEMU
    shl    esi,4
    mov    ecx,offset cwDPMIEMUEnd-cwDPMIEMUStart
    mov    al,1 shl 6
    mov    ah,DescPresent+DescPL0+DescMemory+DescERCode
    mov    di,DpmiEmuCS0
    call    MakeDesc
;
;DPMI emulator data seg.
;
    xor    esi,esi
    mov    si,_cwDPMIEMU
    shl    esi,4
    mov    ecx,offset cwDPMIEMUEnd-cwDPMIEMUStart
    mov    al,1 shl 6
    mov    ah,DescPresent+DescPL3+DescMemory+DescRWData
    mov    di,DpmiEmuDS
    call    MakeDesc
;
;Init PL3 to PL0 call gate.
;
    xor    ecx,ecx
    mov    esi,InitCS0
    xor    al,al
    mov    ah,DescPresent+DescPL3+Desc386Call
    mov    di,InitPL3_2_PL0
    call    MakeDesc
;
;DPMI emulator PL3 to PL0 call gate.
;
    xor    ecx,ecx
    mov    esi,DpmiEmuCS0
    xor    al,al
    mov    ah,DescPresent+DescPL3+Desc386Call
    mov    di,DpmiEmuPL3_2_PL0
    call    MakeDesc
;
;Zero to 4G segment.
;
    xor    esi,esi
    or    ecx,-1
    xor    al,al
    mov    ah,DescPresent+DescPL3+DescMemory+DescRWData
    mov    di,KernalZero
    call    MakeDesc
;
;Main PSP segment.
;
    push    ds
    mov    ax,_cwMain
    mov    ds,ax
    assume ds:_cwMain
    movzx    esi,RealPspSegment
    assume ds:_cwRaw
    pop    ds
    shl    esi,4
    mov    ecx,256
    mov    al,0
    mov    ah,DescPresent+DescPL3+DescMemory+DescRWData
    mov    di,MainPSP
    call    MakeDesc
;
;Main environment var.
;
    push    ds
    mov    ax,_cwMain
    mov    ds,ax
    assume ds:_cwMain
    movzx    esi,RealEnvSegment
    assume ds:_cwRaw
    pop    ds
    shl    esi,4
    mov    ecx,0FFFFh
    xor    al,al
    mov    ah,DescPresent+DescPL3+DescMemory+DescRWData
    mov    di,MainEnv
    call    MakeDesc
;
;Main code seg.
;
    xor    esi,esi
    mov    si,_cwMain
    shl    esi,4
    mov    ecx,65535
    xor    al,al
    mov    ah,DescPresent+DescPL3+DescMemory+DescERCode
    mov    di,MainCS
    call    MakeDesc
;
;Main data seg.
;
    xor    esi,esi
    mov    si,_cwMain
    shl    esi,4
    mov    ecx,65535
    xor    al,al
    mov    ah,DescPresent+DescPL3+DescMemory+DescRWData
    mov    di,MainDS
    call    MakeDesc
;
;Main stack.
;
    xor    esi,esi
    mov    si,_cwStack
    shl    esi,4
    mov    ecx,65535
    mov    al,b[RawSystemFlags]
    xor    al,1
    shl    al,6
    mov    ah,DescPresent+DescPL3+DescMemory+DescRWData
    mov    di,MainSS
    call    MakeDesc
;
;Init code seg.
;
    xor    esi,esi
    mov    si,_cwInit
    shl    esi,4
    mov    ecx,65535
    xor    al,al
    mov    ah,DescPresent+DescPL3+DescMemory+DescERCode
    mov    di,InitCS
    call    MakeDesc
;
;Init code seg at PL0
;
    xor    esi,esi
    mov    si,_cwInit
    shl    esi,4
    mov    ecx,65535
    xor    al,al
    mov    ah,DescPresent+DescPL0+DescMemory+DescERCode
    mov    di,InitCS0
    call    MakeDesc
;
;Init data seg.
;
    xor    esi,esi
    mov    si,_cwInit
    shl    esi,4
    mov    ecx,65535
    xor    al,al
    mov    ah,DescPresent+DescPL3+DescMemory+DescRWData
    mov    di,InitDS
    call    MakeDesc
;
;Init GDT data alias.
;
    mov    esi,GDTLinear
    mov    ecx,65535
    xor    al,al
    mov    ah,DescPresent+DescPL3+DescMemory+DescRWData
    mov    di,GDTData
    call    MakeDesc
;
;Setup TSS registers to run in protected mode. Setup GDT & IDT values.
;
    mov    es,KernalTSSReal
    xor    di,di
    mov    cx,size TSSFields    ;+(4096/8)
    xor    al,al
    cld
    rep    stosb        ;clear TSS & IO map.
    or    ax,-1
    stosw            ;mark end of IO map.
    mov    es:SS0,KernalPL0
    mov    es:ESP0,tPL0StackSize-4
    mov    es:tLDT,KernalLDT
    mov    es:IOMap,size TSSFields    ;set displacement to IO table.
;
;Setup GDT load value.
;
    movzx    eax,GDTReal
    shl    eax,4
    mov    d[GDTVal+2],eax
    mov    w[GDTVal],-1
;
;Setup Windows enhanced mode denial patch.
;
    mov    ax,352fh        ;get existing vector.
    int    21h
    mov    w[OldInt2F],bx
    mov    w[OldInt2F+2],es
    mov    ax,252fh
    mov    dx,offset Int2FPatch
    int    21h
;
;Now patch RAW specific calls.
;
    push    ds
    mov    ax,_cwMain
    mov    ds,ax
    assume ds:_cwMain
    cmp    ProtectedType,1    ;VCPI?
    assume ds:_cwRaw
    pop    ds
    jz    @@VCPI
;
;Use RAW method to switch to protected mode.
;
@@RAW:    .386p
;
;Need to initialise 1st entry of page dir & alias.
;
    movzx    eax,Page1stReal
    shl    eax,4
    or    eax,111b        ;user+write+present
    mov    es,PageDirReal
    xor    di,di
    mov    es:[di],eax
    mov    es,PageAliasReal
    mov    es:[di],eax
    mov    es,KernalTSSReal
    mov    es:[di].tCR3,eax    ;set CR3 in TSS as well.
    ;
    ;map alias into page dir as well.
    ;
    movzx    eax,PageAliasReal    ;get para address.
    shl    eax,4        ;make linear.
    or    eax,111b        ;user+write+present.
    mov    es,PageDirReal
    mov    di,1023*4
    mov    es:[di],eax        ;setup in last page dir entry.
    ;
;    pushfd
;    pop    eax
;    mov    EFlagsSav,eax
    mov    eax,cr3
    mov    CR3Sav,eax
    mov    eax,cr0
    mov    CR0Sav,eax
    sidt    IDTSav        ;save old IDT value for switch back.
    sgdt    GDTSav
    pop    RetAdd
    cli            ;Don't want interupts interfering.
    lgdt    GDTVal        ;Setup GDT &
    lidt    f[IDTVal]        ;IDT.
    mov    eax,VCPI_CR3
    mov    cr3,eax        ;set page dir address.
    mov    eax,cr0        ;Get machine status &
    or    eax,080000001h    ;set PM+PG bits.
    mov    cr0,eax        ;/

; MED 10/15/96
    mov    CR0ProtSav,eax    ; save protected mode status of CR0

    db 0eah        ;Absolute 16-bit jump, to clear
    dw @@RAW0,InitCS0        ;instruction pre-fetch & load CS.
@@RAW0:    mov    ax,KernalLDT        ;Point to empty LDT descriptor.
    lldt    ax        ;and set LDT.
    mov    cx,KernalTS        ;Get value for task register.
    ltr    cx        ;and set it.
    ;
    mov    Protected2Real,offset RawProt2Real
    mov    Real2Protected,offset RawReal2Prot
    jmp    @@inProt
;
;Use VCPI method to switch to protected mode.
;
@@VCPI:    mov    cs:IErrorNumber,6
    cli
    push    ds
    xor    di,di        ;Page table offset.
    mov    es,Page1stReal    ;Page table segment
    mov    si,VCPI_0        ;VCPI GDT entries offset.
    and    si,not 3
    mov    ds,GDTReal        ;GDT segment.
    mov    ax,0de01h        ;Let VCPI server prepare.
    int    67h
    pop    ds
    or    ah,ah
    jnz    InitError
    mov    d[VCPI_Entry],ebx    ;Store entry point.

; MED 11/05/96
    mov    FirstUninitPage,di    ; VCPI server advanced to first uninitialized page
                            ; table entry in client's page

    ;
    ;Now update PHYSICAL addresses of dir & 1st page tables.
    ;
    mov    es,Page1stReal
    movzx    edi,Page1stReal    ;get linear address.
    shl    edi,4        ;/
    shr    edi,12        ;page number.
    shl    edi,2        ;*4 bytes per entry.
    mov    eax,es:[di]        ;get physical address.
    and    eax,not 4095        ;clear status bits.
    or    eax,111b        ;set our bits.
    mov    es,PageDirReal
    xor    di,di
    mov    es:[di],eax
    mov    es,PageAliasReal
    mov    es:[di],eax
    ;
    mov    es,Page1stReal
    movzx    edi,PageDirReal    ;get linear address.
    shl    edi,4        ;/
    shr    edi,12        ;page number.
    shl    edi,2        ;*4 bytes per entry.
    mov    eax,es:[di]        ;get physical address.
    and    eax,0FFFFFFFFh-4095    ;clear status bits.
    mov    VCPI_CR3,eax        ;set VCPI CR3 value as well.
    mov    es,KernalTSSReal
    xor    di,di
    mov    es:[di].tCR3,eax    ;set CR3 in TSS as well.
    ;
    mov    es,Page1stReal
    movzx    edi,PageAliasReal    ;get linear address.
    shl    edi,4        ;/
    shr    edi,12        ;page number.
    shl    edi,2        ;*4 bytes per entry.
    mov    eax,es:[di]        ;get physical address.
    and    eax,0FFFFFFFFh-4095    ;clear status bits.
    or    eax,111b        ;user+write+present.
    mov    es,PageDirReal
    mov    di,1023*4
    mov    es:[di],eax        ;setup in last page dir entry.
    ;
    mov    VCPI_LDT,KernalLDT
    mov    VCPI_EIP,offset @@InProt
    mov    VCPI_TR,KernalTS    ;Get value for task register.
    mov    VCPI_CS,InitCS0
    xor    eax,eax
    mov    ax,seg _cwRaw
    shl    eax,4
    add    eax,offset GDTVal
    mov    VCPI_pGDT,eax
    xor    eax,eax
    mov    ax,seg _cwRaw
    shl    eax,4
    add    eax,offset IDTVal
    mov    VCPI_pIDT,eax
    cli
    mov    ax,0de0ch
    mov    si,seg _cwRaw
    movzx    esi,si
    shl    esi,4
    add    esi,offset VCPI_CR3
    int    67h
    ;
    mov    ax,_cwStack
    mov    ss,ax
    mov    esp,offset _cwStackEnd-4
    mov    ax,_cwRaw
    mov    ds,ax
    jmp    InitError        ;Shouldn't come through here.
;
;We're in protected mode at last, now we just have to move the DPMI emulation
;stuff into extended memory and build a useful IDT.
;
@@InProt:
    mov    ax,InitDS
    mov    ds,ax
    assume ds:_cwInit
    or    IProtectedMode,-1
    mov    ax,KernalDS        ;Get data descriptor.
    mov    ds,ax        ;/
    assume ds:_cwRaw
    mov    es,ax        ;/
    mov    fs,ax        ;/
    mov    gs,ax        ;/
    mov    ax,KernalPL0
    mov    ss,ax        ;/
    mov    esp,offset tPL0StackSize-4
    ;
    pushfd
    pop    eax
    and    ax,1011111111111111b    ;clear NT.
    push    eax
    popfd
    cld
    clts
;
;Switch to PL3 code seg for the hell of it.
;
    .386
    mov    edx,offset _cwStackEnd-4
    mov    ecx,MainSS
    push    ecx        ;SS
    push    edx        ;ESP
    pushfd        ;EFlags
    pop    eax
    and    ax,1000111111111111b    ;clear NT & IOPL.
    or    ax,0011000000000000b    ;force IOPL.
    push    eax
    popfd
    push    eax
    xor    eax,eax
    mov    ax,InitCS
    push    eax        ;CS
    mov    eax,offset @@pl3
    push    eax        ;EIP
    db 66h
    iretd
    ;
@@pl3:    push    es
    mov    ax,KernalZero
    mov    es,ax
    mov    esi,GDTLinear
    add    esi,KernalTS-3
    mov    es:b[esi+5],DescPresent+DescPL3+Desc386Tss
    pop    es
;
;Setup initial segment variables.
;
    push    ds
    mov    ax,MainDS
    mov    ds,ax
    assume ds:_cwMain
    or    w[SystemFlags],32768    ;Flags us in protected mode.
    mov    RealSegment,KernalZero
    mov    PspSegment,MainPSP
    mov    EnvSegment,MainENV
    mov    CodeSegment,MainCS
    mov    DataSegment,MainDS
    mov    StackSegment,MainSS
    assume ds:_cwRaw
    pop    ds
;
;Make sure A20 is enabled.
;
    push    ds
    mov    ax,InitDS
    mov    ds,ax
    assume ds:_cwInit
    mov    IErrorNumber,7
    assume ds:_cwRaw
    pop    ds
    mov    ax,1
    push    cs
    push    offset @@1
    push    KernalCS
    push    offset A20Handler
    retf
@@1:    jnz    InitError
;
;Now get extended memory sorted out, move the page tables into extended memory
;for a start.
;
    push    ds
    mov    ax,InitDS
    mov    ds,ax
    assume ds:_cwInit
    mov    IErrorNumber,5
    assume ds:_cwRaw
    pop    ds
    mov    ax,KernalZero
    mov    es,ax
;
;Allocate 2nd page table so we can map extended memory.
;
    call    d[fPhysicalGetPage]
    jc    InitError
    and    ecx,1        ;put user bits in useful place.
    shl    ecx,10
    and    edx,not 4095        ;lose user bits.

    or    edx,111b        ;present+user+write.
    or    edx,ecx        ;set use flags.
    mov    eax,1
    mov    esi,PageDIRLinear
    mov    es:d[esi+eax*4],edx    ;store this tables address.
    mov    esi,PageAliasLinear    ;get alias table address.
    mov    es:d[esi+eax*4],edx    ;setup in alias table as well.
    call    d[fCR3Flush]
    mov    edi,1024*4096*1023    ;base of page alias's.
    mov    eax,1024*4        ;get the entry number again.
    add    edi,eax
    mov    ecx,4096/4
    xor    eax,eax
    cld
    db 67h
    rep    stosd
    call    d[fCR3Flush]
    mov    LinearEntry,1024
;
;Setup DET page alias.
;
    call    d[fPhysicalGetPage]    ;get page for new page 1st DET.
    jc    InitError
    mov    LinearEntry+8,edx    ;store physical address.
    and    ecx,1        ;put user bits in useful place.
    shl    ecx,10
    and    edx,not 4095        ;lose user bits.
    or    edx,111b        ;present+user+write.
    or    edx,ecx        ;set use flags.
    mov    eax,LinearEntry    ;get the entry number again.
    mov    esi,1024*4096*1023    ;base of page alias's.
    mov    es:d[esi+eax*4],edx    ;set physical address.
    call    d[fCR3Flush]
    mov    edi,LinearEntry
    shl    edi,12
    mov    ecx,4096/4
    xor    eax,eax
    cld
    db 67h
    rep    stosd        ;clear it.
    mov    eax,LinearEntry
    shl    eax,12        ;get linear address.
    mov    PageDETLinear,eax
    mov    eax,1022
    mov    esi,PageDIRLinear
    mov    edx,LinearEntry+8    ;get physical address again.
    or    edx,111b
    mov    es:[esi+eax*4],edx    ;put new page into the map.
    mov    esi,PageALIASLinear
    mov    es:[esi+eax*4],edx    ;put new page into the map.
    call    d[fCR3Flush]
    inc    LinearEntry
;
;Setup DET page 1st.
;
    call    d[fPhysicalGetPage]    ;get page for new page 1st.
    jc    InitError
    mov    LinearEntry+8,edx    ;store physical address.
    and    ecx,1        ;put user bits in useful place.
    shl    ecx,10
    and    edx,not 4095        ;lose user bits.
    or    edx,111b        ;present+user+write.
    or    edx,ecx        ;set use flags.
    mov    esi,1024*4096*1023    ;base of page alias's.
    mov    eax,LinearEntry    ;get the entry number again.
    mov    es:d[esi+eax*4],edx    ;set physical address.
    call    d[fCR3Flush]
    mov    edi,LinearEntry
    shl    edi,12
    mov    ecx,4096/4
    mov    eax,MEM_FILL
    cld
    db 67h
    rep    stosd        ;copy old to new.
    mov    esi,PageDETLinear
    mov    eax,0
    mov    edx,LinearEntry+8    ;get physical address again.
    or    edx,111b
    mov    es:[esi+eax*4],edx    ;put new page into the map.
    call    d[fCR3Flush]
    inc    LinearEntry
;
;Allocate 2nd page DET
;
    call    d[fPhysicalGetPage]    ;get page for new page 1st.
    jc    InitError
    mov    LinearEntry+8,edx    ;store physical address.
    and    ecx,1        ;put user bits in useful place.
    shl    ecx,10
    and    edx,not 4095        ;lose user bits.
    or    edx,111b        ;present+user+write.
    or    edx,ecx        ;set use flags.
    mov    esi,1024*4096*1023    ;base of page alias's.
    mov    eax,LinearEntry    ;get the entry number again.
    mov    es:d[esi+eax*4],edx    ;set physical address.
    call    d[fCR3Flush]
    mov    edi,LinearEntry
    shl    edi,12
    mov    ecx,4096/4
    mov    eax,MEM_FILL
    cld
    db 67h
    rep    stosd        ;copy old to new.
    mov    esi,PageDETLinear
    mov    eax,1
    mov    edx,LinearEntry+8    ;get physical address again.
    or    edx,111b
    mov    es:[esi+eax*4],edx    ;put new page into the map.
    call    d[fCR3Flush]
    inc    LinearEntry
;
;Move page alias into extended memory.
;
    call    d[fPhysicalGetPage]    ;get page for new page 1st.
    jc    InitError
    mov    LinearEntry+8,edx    ;store physical address.
    and    ecx,1        ;put user bits in useful place.
    shl    ecx,10
    and    edx,not 4095        ;lose user bits.
    or    edx,111b        ;present+user+write.
    or    edx,ecx        ;set use flags.
    mov    eax,LinearEntry    ;get the entry number again.
    mov    esi,1024*4096*1023    ;base of page alias's.
    mov    es:d[esi+eax*4],edx    ;set physical address.
    call    d[fCR3Flush]
    push    ds
    mov    esi,PageAliasLinear
    mov    edi,LinearEntry
    shl    edi,12
    mov    ecx,4096/4
    push    es
    pop    ds
    cld
    db 67h
    rep    movsd        ;copy old to new.
    pop    ds
    mov    eax,PageALIASLinear
    mov    PageALIASLinear+4,eax
    mov    eax,LinearEntry
    shl    eax,12        ;get linear address.
    mov    PageALIASLinear,eax
    mov    esi,PageDIRLinear
    mov    eax,1023
    mov    edx,LinearEntry+8    ;get physical address again.
    or    edx,111b
    mov    ecx,es:[esi+eax*4]    ;get origional value.
    mov    PageALIASLinear+8,ecx
    mov    es:[esi+eax*4],edx    ;put new page into the map.
    mov    esi,PageALIASLinear
    mov    eax,1023
    mov    edx,LinearEntry+8    ;get physical address again.
    or    edx,111b
    mov    es:[esi+eax*4],edx    ;put new page into the map.
    call    d[fCR3Flush]
    inc    LinearEntry

; MED 09/19/96
COMMENT !
;
;Move page 1st into extended memory.
;
    call    d[fPhysicalGetPage]    ;get page for new page 1st.
    jc    InitError
    mov    LinearEntry+8,edx    ;store physical address.
    and    ecx,1        ;put user bits in useful place.
    shl    ecx,10
    and    edx,not 4095        ;lose user bits.
    or    edx,111b        ;present+user+write.
    or    edx,ecx        ;set use flags.
    ;
    ;Map it into general linear address space.
    ;
    mov    eax,LinearEntry    ;get the entry number again.
    mov    esi,1024*4096*1023    ;base of page alias's.
    mov    es:d[esi+eax*4],edx    ;set physical address.
    call    d[fCR3Flush]
    ;
    ;Copy table to new memory.
    ;
    push    ds
    mov    esi,Page1stLinear
    mov    edi,LinearEntry
    shl    edi,12
    mov    ecx,4096/4
    push    es
    pop    ds
    cld
    db 67h
    rep    movsd        ;copy old to new.
    pop    ds
    ;
    ;Make variables point to new memory.
    ;
    mov    eax,Page1stLinear
    mov    Page1stLinear+4,eax    ;store old address.
    mov    eax,LinearEntry
    shl    eax,12        ;get linear address.
    mov    Page1stLinear,eax    ;set new linear address.
    ;
    ;Set new address in page dir.
    ;
    mov    edx,LinearEntry+8    ;get physical address again.
    or    edx,111b
    ;
    mov    esi,PageDIRLinear
    mov    eax,0
    mov    ecx,es:[esi+eax*4]    ;get origional value.
    mov    Page1stLinear+8,ecx
    mov    es:[esi+eax*4],edx    ;put new page into the map.
    call    d[fCR3Flush]
    ;
    ;Set new address in page dir alias.
    ;
    mov    esi,PageALIASLinear
    mov    eax,0
    mov    es:[esi+eax*4],edx    ;put new page into the map.
    call    d[fCR3Flush]
    inc    LinearEntry
END COMMENT !

;
;Move page dir into extended memory.
;
    call    d[fPhysicalGetPage]    ;get page for new page DIR.
    jc    InitError
    mov    LinearEntry+8,edx    ;store physical address.
    and    ecx,1        ;put user bits in useful place.
    shl    ecx,10
    and    edx,not 4095        ;lose user bits.
    or    edx,111b        ;present+user+write.
    or    edx,ecx        ;set use flags.
    ;
    ;Map it into normal linear address space.
    ;
    mov    eax,LinearEntry    ;get the entry number again.
    mov    esi,1024*4096*1023    ;base of page alias's.
    mov    es:d[esi+eax*4],edx    ;set physical address.
    call    d[fCR3Flush]
    ;
    ;Copy table to new memory.
    ;
    push    ds
    mov    esi,PageDIRLinear
    mov    edi,LinearEntry
    shl    edi,12
    mov    ecx,4096/4
    push    es
    pop    ds
    cld
    db 67h
    rep    movsd        ;copy old to new.
    pop    ds
    ;
    ;Make variables point to new memory.
    ;
    mov    eax,PageDirLinear
    mov    PageDIRLinear+4,eax    ;store old value.
    mov    eax,LinearEntry
    shl    eax,12        ;get linear address.
    mov    PageDIRLinear,eax    ;set new value.
    mov    eax,VCPI_CR3
    mov    PageDIRLinear+8,eax    ;store old physical address.
    mov    eax,LinearEntry+8
    mov    VCPI_CR3,eax        ;set new physical address.
    movzx    edi,KernalTSSReal
    shl    edi,4
    mov    es:[edi].tCR3,eax    ;set CR3 in TSS as well.
    call    d[fCR3Flush]
    inc    LinearEntry
;
;Setup IDT.
;
    call    d[fPhysicalGetPage]    ;get page for new page DIR.
    jc    InitError
    mov    LinearEntry+8,edx    ;store physical address.
    and    ecx,1        ;put user bits in useful place.
    shl    ecx,10
    and    edx,not 4095        ;lose user bits.
    or    edx,111b        ;present+user+write.
    or    edx,ecx        ;set use flags.
    mov    eax,LinearEntry    ;get the entry number again.
    mov    esi,1024*4096*1023    ;base of page alias's.
    mov    es:d[esi+eax*4],edx    ;set physical address.
    call    d[fCR3Flush]
    mov    eax,LinearEntry
    shl    eax,12
    mov    d[IDTVal+2],eax
    mov    w[IDTVal],0+(256*8)-1
    ;
    mov    bp,256        ;number of vectors.
    mov    ecx,offset InterruptHandler ;code address.
    mov    esi,DpmiEmuCS0    ;gate to use.
    mov    al,0
    mov    ah,DescPresent+DescPL3+Desc386Int
    mov    edi,d[IDTVal+2]
@@3:    call    MakeDesc2
    add    edi,8        ;next table address.
    add    ecx,8        ;/
    dec    bp
    jnz    @@3
    inc    LinearEntry
    ;
    ;Re-load IDT value.
    ;
    push    es
    mov    edi,offset MemIntBuffer
    push    ds
    pop    es
    mov    Real_CS[edi],_cwInit
    mov    Real_IP[edi],offset IDTFlush
    mov    Real_SS[edi],0
    mov    Real_SP[edi],0
    call    d[fRawSimulateFCALL]
    pop    es
;
;Get extended memory for DPMI emulator.
;
    push    ds
    mov    ax,InitDS
    mov    ds,ax
    assume ds:_cwInit
    mov    IErrorNumber,5
    assume ds:_cwRaw
    pop    ds
    ;
    mov    ebp,offset cwDPMIEMUEnd-cwDPMIEMUStart
    add    ebp,4095
    shr    ebp,12        ;Get number of pages needed.
    mov    eax,LinearEntry
    shl    eax,12
    mov    LinearEntry+4,eax    ;Store start address.
@@2:    call    d[fPhysicalGetPage]    ;try to allocate a page.
    jc    InitError
    and    ecx,1        ;put user bits in useful place.
    shl    ecx,10
    and    edx,not 4095        ;lose user bits.
    or    edx,111b        ;present+user+write.
    or    edx,ecx        ;set use flags.
    mov    eax,LinearEntry    ;get the entry number again.
    mov    esi,1024*4096*1023    ;base of page alias's.
    mov    es:d[esi+eax*4],edx    ;set physical address.
    call    d[fCR3Flush]
    inc    LinearEntry        ;update pointer.
    dec    ebp
    jnz    @@2
;
;Copy DPMI emulator code into extended memory we just allocated.
;
    mov    edi,LinearEntry+4    ;Get the destination.
    mov    si,_cwDPMIEMU
    movzx    esi,si
    shl    esi,4        ;Point to the source.
    mov    ecx,offset cwDPMIEMUEnd-cwDPMIEMUStart
    shr    ecx,2
    push    ds
    push    es
    pop    ds
    cld
    db 67h
    rep    movsd        ;Copy it up their.
    pop    ds
;
;Setup DPMI emulator selectors.
;
    push    es
    mov    ax,GDTData
    mov    es,ax
    mov    esi,LinearEntry+4
    mov    ecx,offset cwDPMIEMUEnd-cwDPMIEMUStart
    mov    al,1 shl 6
    mov    ah,DescPresent+DescPL3+DescMemory+DescERCode
    mov    di,DpmiEmuCS
    call    MakeDesc
    mov    esi,LinearEntry+4
    mov    ecx,offset cwDPMIEMUEnd-cwDPMIEMUStart
    mov    al,1 shl 6
    mov    ah,DescPresent+DescPL0+DescMemory+DescERCode
    mov    di,DpmiEmuCS0
    call    MakeDesc
    mov    esi,LinearEntry+4
    mov    ecx,offset cwDPMIEMUEnd-cwDPMIEMUStart
    mov    al,1 shl 6
    mov    ah,DescPresent+DescPL3+DescMemory+DescRWData
    mov    di,DpmiEmuDS
    call    MakeDesc
    pop    es
;
;Should be OK to enable interrupts at last.
;
    mov    ah,1
    int    16h
    sti
;
;Initialise hardware interrupt call-back's.
;
    call    InitHardwareInts
;
;Allocate memory for new GDT/LDT
;
    push    ds
    mov    ax,InitDS
    mov    ds,ax
    assume ds:_cwInit
    mov    IErrorNumber,5
    assume ds:_cwRaw
    pop    ds
    ;
    mov    ebp,(8192*8)+8192
    shr    ebp,12        ;Get number of pages needed.
    mov    eax,LinearEntry
    shl    eax,12
    mov    LinearEntry+4,eax    ;Store start address.
@@6:    call    d[fPhysicalGetPage]    ;try to allocate a page.
    jc    InitError
    and    ecx,1        ;put user bits in useful place.
    shl    ecx,10
    and    edx,not 4095        ;lose user bits.
    or    edx,111b        ;present+user+write.
    or    edx,ecx        ;set use flags.
    mov    eax,LinearEntry    ;get the entry number again.
    mov    esi,1024*4096*1023    ;base of page alias's.
    mov    es:d[esi+eax*4],edx    ;set physical address.
    call    d[fCR3Flush]
    inc    LinearEntry        ;update pointer.
    dec    ebp
    jnz    @@6
    ;
    mov    esi,LinearEntry+4
    mov    MDTLinear,esi    ;store for allocation code.
    mov    MDTLinear+4,esi
    add    MDTLinear+4,8192*8    ;setup bit string address.
    ;
    ;Clear the memory to zero's.
    ;
    mov    edi,MDTLinear
    mov    ecx,(8192*8)+8192
    cld
    xor    al,al
    db 67h
    rep    stosb
    mov    edi,MDTLinear+4
    or    es:d[edi],-1        ;Force VCPI values to not used.
    ;
    ;See which table we want to use.
    ;
    test    RawSystemFlags,128    ;GDT or LDT?
    jnz    @@LDT
    ;
    ;Setup a new GDT.
    ;
    mov    esi,MDTLinear
    mov    GDTLinear+4,esi
    mov    ecx,65535
    xor    al,al
    mov    ah,DescPresent+DescPL3+DescMemory+DescRWData
    mov    di,GDTData
    push    es
    mov    es,di
    call    MakeDesc
    pop    es
    ;
    ;Copy current GDT to new GDT.
    ;
    push    ds
    mov    esi,GDTLinear
    mov    edi,GDTLinear+4
    mov    ax,KernalZero
    mov    ds,ax
    mov    ecx,GDT_Entries*8
    cld
    db 67h
    rep    movsb
    pop    ds
    ;
    ;Set new GDT values.
    ;
    pushf
    cli
    mov    eax,GDTLinear
    mov    GDTLinear+8,eax
    mov    eax,GDTLinear+4
    mov    GDTLinear,eax
    mov    d[GDTVal+2],eax
    mov    d[VCPI_GDT+2],eax
    popf
    ;
    ;Now mark all used descriptors in allocation control string.
    ;
    mov    edi,GDTLinear
    mov    esi,MDTLinear+4
    mov    cx,GDT_Entries
@@4:    test    es:b[edi+5],DescPresent    ;this descriptor in use?
    jz    @@5
    or    es:b[esi],-1
@@5:    add    edi,8        ;next descriptor.
    inc    esi        ;update descriptor number.
    dec    cx
    jnz    @@4
    ;
    ;Now setup extra GDT descriptors.
    ;
    push    es
    mov    ax,GDTData
    mov    es,ax
    ;
    mov    di,KernalB000
    mov    esi,0b0000h
    mov    ecx,65535
    xor    al,al
    mov    ah,DescPresent+DescPL3+DescMemory+DescRWData
    call    MakeDesc
    ;
    mov    di,KernalB800
    mov    esi,0b8000h
    mov    ecx,65535
    xor    al,al
    mov    ah,DescPresent+DescPL3+DescMemory+DescRWData
    call    MakeDesc
    ;
    mov    di,KernalA000
    mov    esi,0a0000h
    mov    ecx,65535
    xor    al,al
    mov    ah,DescPresent+DescPL3+DescMemory+DescRWData
    call    MakeDesc
    pop    es
    ;
@@LDT:    ;Setup new LDT.
    ;
    mov    esi,MDTLinear
    mov    LDTLinear,esi
    ;
    ;Map LDT into GDT.
    ;
    push    es
    mov    ax,GDTData
    mov    es,ax
    mov    di,KernalLDT
    mov    esi,LDTLinear
    mov    ecx,8192*8
    xor    al,al
    mov    ah,DescPresent+DescPL3+DescLDT
    call    MakeDesc
    pop    es
    ;
    mov    ah,1
    int    16h        ;force GDT/LDT reload with mode switch.
;
;Initialise application memory pool.
;
    mov    eax,LinearEntry
    shl    eax,12
    mov    LinearBase,eax
    add    eax,4096
    mov    LinearLimit,eax
    ;
    call    d[fPhysicalGetPage]    ;try to allocate a page.
    jc    InitError

    and    ecx,1        ;put user bits in useful place.
    shl    ecx,10
    and    edx,not 4095        ;lose user bits.
    or    edx,111b        ;present+user+write.
    or    edx,ecx        ;set use flags.
    mov    eax,LinearEntry    ;get the entry number again.
    mov    esi,1024*4096*1023    ;base of page alias's.
    mov    es:d[esi+eax*4],edx    ;set physical address.
    call    d[fCR3Flush]
    mov    eax,LinearEntry    ;get the entry number again.
    mov    esi,1024*4096*1022
    mov    es:d[esi+eax*4],0    ;clear this pages details.
;
;Initialise virtual memory manager stuff.
;
    call    d[fPhysicalGetPages]    ;find free pages.
    mov    eax,edx
    shl    eax,12
    add    eax,LinearLimit
    sub    eax,LinearBase
    mov    ebp,eax        ;save this for comparisons.
    mov    di,InitDS
    mov    fs,di
    mov    di,offset VMMDrivPath1    ;point to start of paths.
    assume fs:_cwInit
    cmp    fs:NoVMSwitch,0
    assume fs:nothing
    jnz    @@v9
    ;
    ;Work through list of posibles till we find a useful entry.
    ;
@@v0:
    cmp    fs:b[di],0
    jz    @@v7
    cmp    fs:b[di],-1
    jz    @@v9
    ;
    ;Check drive is valid and has enough free space.
    ;

COMMENT !
; MED 10/11/96
; if no drivespec, then use default drive
    cmp    BYTE PTR fs:[di+1],':'
    je    isdrive

    movzx    edx,di    ; scan to end of current pathspec
defloop:
    inc    dx            ; edx known 16-bit value so 16-bit increment is valid
    cmp    BYTE PTR fs:[edx],0
    jne    defloop

; at end of current pathspec, now shift forward two bytes to allow for drive
shiftloop:
    mov    al,fs:[edx]
    mov    fs:[edx+2],al
    dec    dx
    cmp    di,dx        ; edx known 16-bit value so 16-bit compare is valid
    jae    shiftloop

    push    edi
    mov    edi,offset PageInt
    push    ds
    pop    es
    mov    [edi].Real_EAX,1900h
    mov    Real_SS[edi],0
    mov    Real_SP[edi],0
    mov    bl,21h
    call    d[fRawSimulateINT]
    mov    al,BYTE PTR [edi].Real_EAX
    pop    edi
    add    al,'A'        ; convert to drive
    mov    fs:[di],al
    mov    BYTE PTR fs:[di+1],':'    ; add colon to drivespec
END COMMENT !

isdrive:
    mov    dl,fs:[di]        ;get swap file drive.
    cmp    dl,61h        ; 'a'
    jb    @@v1
    cmp    dl,7Ah        ; 'z'
    ja    @@v1
    and    dl,5Fh        ;convert to upper case.
@@v1:    sub    dl,'A'        ;make it real.
    inc    dl        ;adjust for current type selection.

drivefree:
    mov    ah,36h        ;get free space.
    push    ebp
    int    21h        ;/
    pop    ebp
    cmp    ax,-1        ;invalid drive?
    jz    @@v7
    mul    cx        ;Get bytes per cluster.
    mul    bx        ;Get bytes available.
    shl    edx,16
    mov    dx,ax
    cmp    edx,ebp        ;Enough free space.
    jc    @@v7
    ;
    ;See if we can create a temp file.
    ;

; MED 02/25/96, use name specified in CAUSEWAY e-var
    test    DesiredVMMName,-1
    je    med5a            ; no VMM name request
    push    di
    mov    si,di
    push    si            ; save -> filespec start

; find end of pathspec
mednameloop:
    cmp    BYTE PTR fs:[si],0
    je    medndone
    inc    si
    jmp    mednameloop

; append desired name on filespec
medndone:

; 05/15/98
; check for backslash already existing
    cmp    BYTE PTR fs:[si-1],'\'
    je    medbs

    mov    BYTE PTR fs:[si],'\'
    inc    si

medbs:
    mov    di,offset DesiredVMMName

medtransloop:
    mov    al,[di]
    mov    fs:[si],al
    inc    di
    inc    si
    test    al,al
    jne    medtransloop
    pop    si                ; restore si -> filespec start

    mov    edi,offset PageInt
    push    ds
    pop    es
    mov    [edi].Real_DS,_cwInit
    mov    [edi].Real_EDX,esi
    mov    [edi].Real_EAX,3c00h
    mov    [edi].Real_ECX,0
    mov    Real_SS[edi],0
    mov    Real_SP[edi],0
    mov    bl,21h
    call    d[fRawSimulateINT]
    test    Real_Flags[edi],1
    mov    eax,Real_EAX[edi]
    pop    di
    jz    @@v8
    jmp    @@v7
    ;

med5a:
    push    di
    mov    si,di
    mov    edi,offset PageInt
    push    ds
    pop    es
    mov    [edi].Real_DS,_cwInit
    mov    [edi].Real_EDX,esi
    mov    [edi].Real_EAX,5a00h
    mov    [edi].Real_ECX,0
    mov    Real_SS[edi],0
    mov    Real_SP[edi],0
    mov    bl,21h
    call    d[fRawSimulateINT]
    test    Real_Flags[edi],1
    mov    eax,Real_EAX[edi]
    pop    di
    jz    @@v8
    ;
@@v7:    add    di,128
    jmp    @@v0
    ;
@@v8:    ;Store the handle and copy the name accross.
    ;
    mov    VMMHandle,ax        ;store the handle.
    pushm    ds,fs
    pop    ds
    mov    di,offset VMMName
    mov    cx,128
    rep    movsb
    pop    ds
    mov    al,VMMName
    cmp    al,61h        ; 'a'
    jb    @@v2
    cmp    al,7Ah        ; 'z'
    ja    @@v2
    and    al,5Fh        ;convert to upper case.
@@v2:    mov    VMMName,al

; MED 02/25/96, if pre-allocate, then force write to allocated size
    cmp    PreAllocSize,0
    je    medpre2
    mov    bx,VMMHandle
    mov    ecx,PreAllocSize
    mov    dx,cx
    shr    ecx,16
    mov    ax,4200h    ; seek from beginning of file
    int    21h
    xor    cx,cx        ; write zero bytes (pre-allocating based on seek)
    mov    ah,40h        ; write to file
    int    21h
    mov    ah,68h        ; commit file
    int    21h
    xor    dx,dx        ; get current size of swap file
    mov    cx,dx
    mov    ax,4202h
    int    21h
    mov    WORD PTR SwapFileLength,ax    ; update internal swapfile length variable
    mov    WORD PTR SwapFileLength+2,dx

medpre2:
    ;
    ;Now patch the exception vector.
    ;
    mov    bl,14        ;Page fault vector.
    movzx    eax,bl
    mov    ebx,eax
    shl    ebx,1        ;*2
    mov    eax,ebx
    shl    ebx,1        ;*4
    add    ebx,eax        ;*6
    push    ds
    mov    ax,DpmiEmuDS
    mov    ds,ax
    assume ds:_cwDPMIEMU
    add    ebx,offset ExceptionTable
    mov    edx,[ebx]        ;get offset.
    mov    cx,4[ebx]        ;get segment selector.
    mov    w[OldExcep14+4],cx
    mov    d[OldExcep14],edx    ;store 32 bit offset.
    mov    d[ebx],offset VirtualFault    ;set offset.
    mov    w[ebx+4],DpmiEmuCS    ;set segment selector.
    or    DpmiEmuSystemFlags,1 shl 1 ;flag VMM's presence.
    mov    ax,MainDS
    mov    ds,ax
    assume ds:_cwMain
    or    SystemFlags,1 shl 1    ;flag VMM's presence.
    assume ds:_cwRaw
    pop    ds
    or    RawSystemFlags,1 shl 1    ;flag VMM's presence.
@@v9:    ;
    push    ds
    pop    fs

    mov    ax,InitDS
    mov    ds,ax
    assume ds:_cwInit
    jmp    @@InProtected
;
;Do initialisations needed for DPMI
;
@@InitDPMI:    mov    ax,_cwMain
    mov    ds,ax
    assume ds:_cwMain
;
;Get some memory for the transfer buffer.
;
    mov    cs:IErrorNumber,5
    mov    bx,8192/16
    mov    ah,48h
    int    21h        ;get memory for transfer buffer.
    jc    InitError
    mov    TransferReal,ax
;
;Get some memory for the INT buffer.
;
    mov    bx,((RawStackTotal/2)/16)+1
    mov    ah,48h
    int    21h
    jc    InitError
    mov    DPMIStackSeg,ax
    mov    DPMIStackOff,RawStackTotal/2
;
;Do instalation check and get mode switch address.
;
    mov    cs:IErrorNumber,9
    mov    ax,1687h        ;DPMI instalation check.
    int    2fh
    or    ax,ax        ;None-zero means its not there.
    jnz    InitError
;
;Check for 32-bit support if needed.
;
    test    SystemFlags,1 shl 14    ;Dual mode?
    jnz    @@Use16Bit23
    ;
    test    SystemFlags,1
    jz    @@Use32Bit23
    jmp    @@Use16Bit23
@@Use32Bit23:    mov    cs:IErrorNumber,9
    test    bx,1        ;Must offer 32 bit support.
    jz    InitError
@@Use16Bit23:    mov    bx,si        ;Get DPMI save buffer size.
    mov    ax,si
    or    bx,bx
    jz    @@d0        ;No guarante that it'll need it.
;
;Allocate memory for DPMI state save buffer.
;
    mov    cs:IErrorNumber,5
    push    di
    push    es
    mov    ah,48h
    int    21h        ;Try and claim memory for it.
    pop    es
    pop    di
    mov    bx,ax
    jc    InitError
@@d0:    pushm    ax,ds
    mov    ax,_cwInit
    mov    ds,ax
    assume ds:_cwInit
    mov    DPMISwitch,di    ;Store the switch call address.
    mov    DPMISwitch+2,es
    mov    es,bx
    popm    ax,ds
    assume ds:_cwMain
;
;Attempt to switch mode.
;
    test    SystemFlags,1
    jz    @@Use32Bit24
    xor    ax,ax        ;16 bit segments for this code.
    jmp    @@Use16Bit24
@@Use32Bit24:    mov    ax,1        ;32 bit segments for this code.
@@Use16Bit24:    push    ax
    mov    ax,_cwInit
    mov    ds,ax
    pop    ax
    assume ds:_cwInit
    pusha
    call    d[DPMISwitch]    ;Make the switch.
    popa
    jnc    @@DpmiInProtected
    mov    IErrorNumber,9
    push    ax
    mov    ax,_cwMain
    mov    ds,ax
    pop    ax
    assume ds:_cwMain
    test    w[SystemFlags+2],1    ;Dual mode?
    jz    InitError
    xor    SystemFlags,1
    xor    ax,1        ;toggle the mode.
    push    ax
    mov    ax,_cwInit
    mov    ds,ax
    pop    ax
    assume ds:_cwInit
    call    d[DPMISwitch]    ;Make the switch.
    jc    InitError        ;really isn't feeling well.
@@DpmiInProtected:
    mov    iDataSegment,ds
    mov    iCodeSegment,cs
    mov    iStackSegment,ss
    mov    iPSPSegment,es
    xor    eax,eax
    mov    ax,sp
    mov    esp,eax
    mov    ax,es:[2ch]
    mov    iENVSegment,ax
;
;Create _cwMain code segment.
;
    mov    iErrorNumber,8
    mov    ax,0000h
    mov    cx,1
    int    31h        ;allocate a selector.
    jc    InitError
    mov    mCodeSegment,ax
    mov    bx,ax
    push    ds
    pop    es
    mov    di,offset dpmiSelBuffer
    mov    si,_cwMain
    movzx    esi,si
    shl    esi,4
    mov    ecx,65535
    xor    al,al
    mov    ah,DescPresent+DescPL3+DescMemory+DescERCode
    call    MakeDesc
    mov    ax,000ch
    push    ds
    pop    es
    mov    edi,offset dpmiSelBuffer
    int    31h
;
;Create _cwMain data segment.
;
    mov    iErrorNumber,8
    mov    ax,0000h
    mov    cx,1
    int    31h        ;allocate a selector.
    jc    InitError
    mov    mDataSegment,ax
    mov    bx,ax
    push    ds
    pop    es
    mov    di,offset dpmiSelBuffer
    mov    si,_cwMain
    movzx    esi,si
    shl    esi,4
    mov    ecx,65535
    xor    al,al
    mov    ah,DescPresent+DescPL3+DescMemory+DescRWData
    call    MakeDesc
    mov    ax,000ch
    push    ds
    pop    es
    mov    edi,offset dpmiSelBuffer
    int    31h
;
;Create a 0-4G selector.
;
    mov    iErrorNumber,8
    mov    ax,0000h
    mov    cx,1
    int    31h        ;allocate a selector.
    jc    InitError
    mov    iRealSegment,ax
    mov    bx,ax
    push    ds
    pop    es
    mov    di,offset dpmiSelBuffer
    xor    esi,esi
    or    ecx,-1
    xor    al,al
    mov    ah,DescPresent+DescPL3+DescMemory+DescRWData
    call    MakeDesc
    mov    ax,000ch
    push    ds
    pop    es
    mov    edi,offset dpmiSelBuffer
    int    31h
;
;Make main seg addressable now.
;
    mov    ax,mDataSegment
    mov    es,ax
    assume es:_cwMain
    mov    ax,mCodeSegment
    mov    es:CodeSegment,ax
    mov    es:w[TerminationHandler+4],ax
    mov    ax,mDataSegment
    mov    es:DataSegment,ax
    mov    ax,iStackSegment
    mov    es:StackSegment,ax
    mov    ax,iPSPSegment
    mov    es:PSPSegment,ax
    mov    ax,iENVSegment
    mov    es:ENVSegment,ax
    mov    ax,iRealSegment
    mov    es:RealSegment,ax
    mov    ax,iCodeSegment
    mov    es:CodeSegmenti,ax
    mov    ax,iDataSegment
    mov    es:DataSegmenti,ax
    push    es
    pop    ds
    assume es:nothing
    assume ds:_cwMain


;
;Patch INT 21h exec function to preserve the stack.
;
    if    0
    mov    bl,21h
    mov    ax,200h
    int    31h
    mov    w[OldInt21hExec],dx
    mov    w[OldInt21hExec+2],cx
    mov    dx,offset Int21hExecPatch
    mov    cx,_cwMain
    mov    bl,21h
    mov    ax,201h
    int    31h
    endif
;
;Make right stuff addresable again.
;
    mov    ds,DataSegmenti
    assume ds:_cwInit
    or    IProtectedMode,-1
;
;Now get on with installing the higher level stuff.
;
@@InProtected:    mov    ax,mDataSegment
    mov    ds,ax
    assume ds:_cwMain
    ;
    mov    ax,ProtectedType    ;Copy protected mode environment type into common
    shl    ax,1+1        ;variable for application access. Might become useful
    or    w[SystemFlags],ax    ;at some point. Other flags can be added at will.
    mov    ax,ProtectedFlags
    shl    ax,1+1+2
    or    w[SystemFlags],ax
    or    w[SystemFlags],32768    ;Flags us in protected mode.
    ;
    mov    ax,DataSegmenti
    mov    ds,ax
    assume ds:_cwInit
;
;Add CW API patch to int 31h and 2Fh.
;
    mov    IErrorNumber,5
    xor    bx,bx
    mov    cx,offset _apiCodeEnd-_apiCodeStart
    mov    ax,0501h
    int    31h        ;Get memory.
    jc    InitError
    xor    si,si
    mov    di,offset _apiCodeEnd-_apiCodeStart
    mov    ax,0600h
    int    31h        ;Lock memory.
    jc    InitError
    shl    ebx,16
    mov    bx,cx
    mov    dpmiSelBase,ebx
;
;Allocate code selector.
;
    mov    iErrorNumber,8
    mov    ax,0000h
    mov    cx,1
    int    31h        ;allocate a selector.
    jc    InitError
    mov    dpmiCodeSel,ax
    mov    bx,ax
    push    ds
    pop    es
    mov    di,offset dpmiSelBuffer
    mov    esi,dpmiSelBase
    mov    ecx,offset _apiCodeEnd-_apiCodeStart
    mov    al,1 shl 6
    mov    ah,DescPresent+DescPL3+DescMemory+DescERCode
    call    MakeDesc
    mov    ax,000ch
    push    ds
    pop    es
    mov    edi,offset dpmiSelBuffer
    int    31h
;
;Allocate data selector.
;
    mov    iErrorNumber,8
    mov    ax,0000h
    mov    cx,1
    int    31h        ;allocate a selector.
    jc    InitError
    mov    dpmiDataSel,ax
    mov    bx,ax
    push    ds
    pop    es
    mov    di,offset dpmiSelBuffer
    mov    esi,dpmiSelBase
    mov    ecx,offset _apiCodeEnd-_apiCodeStart
    xor    al,al
    mov    ah,DescPresent+DescPL3+DescMemory+DescRWData
    call    MakeDesc
    mov    ax,000ch
    push    ds
    pop    es
    mov    edi,offset dpmiSelBuffer
    int    31h
;
;Copy API code into the new memory.
;
    pushm    ds,es
    mov    es,dpmiDataSel
    mov    ds,iRealSegment
    xor    edi,edi
    mov    esi,edi
    mov    si,seg _apiCode
    shl    esi,4
    mov    ecx,offset _apiCodeEnd-_apiCodeStart
    db 67h
    rep    movsb
    popm    ds,es
;
;Setup descriptors in new memory.
;
    pushm    ds,es
    mov    es,dpmiDataSel
    mov    ds,mDataSegment
    assume ds:_cwMain
    assume es:_apiCode
    mov    es:apiDSeg,ds
    mov    es:apiDDSeg,es
    mov    eax,d[SystemFlags]
    mov    es:d[apiSystemFlags],eax
;
;Set INT vector to bring API code into play.
;
    mov    bl,31h
    mov    ax,204h
    int    31h
    test    SystemFlags,1
    jz    @@Use32
    mov    es:w[OldIntSys],dx
    mov    es:w[OldIntSys+2],cx
    jmp    @@Use0
@@Use32:    mov    es:d[OldIntSys],edx
    mov    es:w[OldIntSys+4],cx
@@Use0:    mov    bl,31h
    mov    edx,offset cwAPIpatch
    pushm    ax,ds
    mov    ax,DataSegmenti
    mov    ds,ax
    assume ds:_cwInit
    mov    cx,dpmiCodeSel
    assume ds:_cwMain
    popm    ax,ds
    mov    ax,205h
    int    31h
;
;Copy version through to API.
;
    mov    al,b[VersionMajor]
    sub    al,'0'
    mov    es:cwMajorVersion,al
    mov    al,b[VersionMinor]
    sub    al,'0'
    shl    al,1    ;*2
    mov    ah,al
    shl    al,2    ;*8
    add    ah,al
    mov    al,b[VersionMinor+1]
    sub    al,'0'
    add    al,ah
    mov    es:cwMinorVersion,al
    assume es:nothing
    assume ds:_cwInit
    popm    ds,es
;
;Set flag so we know the API is in place.
;
    mov    ax,dpmiDataSel
    mov    apiDataSegi,ax
    mov    bx,dpmiCodeSel
    push    ds
    mov    ds,mDataSegment
    assume ds:_cwMain
    mov    apiDataSeg,ax
    mov    apiCodeSeg,bx
    mov    d[TerminationHandler],offset InitError
    mov    w[TerminationHandler+4],cs
    assume ds:_cwInit
    pop    ds
;
;Sort out state save address & size.
;
    push    ds
    mov    ds,mDataSegment
    assume ds:_cwMain
    mov    ax,0305h
    int    31h
    jc    @@NoState
    mov    w[DPMIStateSize],ax
    mov    w[DPMIStateSize+2],0
    test    SystemFlags,1
    jz    @@DS_Use32
    mov    w[DPMIStateAddr+2],si
    mov    w[DPMIStateAddr],di
    jmp    @@NoState
@@DS_Use32:    mov    w[DPMIStateAddr+4],si
    mov    d[DPMIStateAddr],edi
    ;
@@NoState:    pop    ds
    assume ds:_cwInit
;
;Patch exception vectors to put API handlers in place.
;
    mov    ax,cs
    push    ax
    mov    ax,offset @@pe0
    push    ax
    mov    ax,dpmiCodeSel
    push    ax
    mov    eax,offset PatchExc
    push    ax
    retf
@@pe0:    ;
;
;Get memory for new PSP.
;
    mov    IErrorNumber,5
    mov    ecx,(size PSP_Struc)+(size EPSP_Struc)
    sys    GetMem32
    jc    InitError
    push    ds
    mov    ds,mDataSegment
    assume ds:_cwMain
    xchg    bx,PSPSegment
    pushm    ds,es
    mov    es,PSPSegment
    mov    ds,bx
    xor    si,si
    xor    di,di
    mov    cx,256/4
    rep    movsd
    popm    ds,es
    assume ds:_cwInit
    pop    ds
;
;Initialise PSP fields.
;
    mov    IErrorNumber,8
    push    ds
    push    es
    mov    ds,mDataSegment
    assume ds:_cwMain
    xor    edx,edx
    mov    es,PSPSegment
    mov    ax,EnvSegment
    mov    es:[PSP_Environment],ax    ;Setup ENV in PSP.
    mov    ax,RealENVSegment
    mov    es:w[EPSP_RealENV],ax
    mov    ax,offset Int21hExecCount
    mov    es:w[EPSP_ExecCount],ax
    mov    es:w[EPSP_ExecCount+2],ds
    mov    es:d[EPSP_Resource],edx    ;Clear memory fields.
    mov    es:d[EPSP_INTMem],edx
    mov    es:d[EPSP_DPMIMem],edx
    mov    es:w[EPSP_Parent],es    ;set parent PSP.
    mov    es:w[EPSP_Next],dx
    mov    es:d[EPSP_DTA],80h    ;Use default PSP DTA.
    mov    es:w[EPSP_DTA+4],es
    mov    eax,16384-(mcbChunkLen+mcbLen)
    mov    es:d[EPSP_mcbMaxAlloc],eax
    mov    es:d[EPSP_mcbHead],edx
    mov    es:w[EPSP_SegBase],0
    mov    es:w[EPSP_SegSize],0
    mov    es:d[EPSP_LastPSP],0
    mov    es:d[EPSP_NextPSP],0
    mov    es:d[EPSP_Exports],0
    mov    es:d[EPSP_Imports],0
    mov    es:d[EPSP_Links],80000000h
    mov    es:d[EPSP_EntryCSEIP+4],0
    mov    es:w[EPSP_PSPSel],es
    mov    BasePSP,es
    mov    bx,es
    sys    GetSelDet32
    mov    BasePSPAddress,edx
    ;
    sys    GetSel
    jc    InitError
    movzx    edx,es:w[PSP_HandlePtr+2]
    shl    edx,4
    movzx    ecx,es:w[PSP_Handles]
    movzx    eax,es:w[PSP_HandlePtr]
    add    edx,eax
    sys    SetSelDet32
    mov    dx,bx
@@normal:    mov    es:w[PSP_HandlePtr+2],dx
    mov    es:w[PSP_HandlePtr],0
    pop    es
    assume ds:_cwInit
    pop    ds
;
;Setup transfer buffer and selector.
;
    mov    IErrorNumber,8
    sys    GetSel
    jc    InitError
    push    ds
    mov    ds,mDataSegment
    assume ds:_cwMain
    movzx    edx,TransferReal
    shl    edx,4
    mov    ecx,TransferSize
    sys    SetSelDet32
    jc    InitError
    push    es
    mov    es,PSPSegment
    mov    es:w[EPSP_TransProt],bx
    mov    ax,TransferReal
    mov    es:w[EPSP_TransReal],ax
    mov    eax,TransferSize
    mov    es:d[EPSP_TransSize],eax
    pop    es
    assume ds:_cwInit
    pop    ds
;
;Setup internaly EXPORT'ed symbols.
;
    mov    bx,dpmiDataSel
    sys    GetSelDet32
    mov    edi,edx
    add    edi,offset apiExports
    push    ds
    mov    ds,mDataSegment
    assume ds:_cwMain
    push    es
    mov    es,PSPSegment
    mov    es:d[EPSP_Exports],edi
    mov    es,RealSegment
    mov    ebp,es:[edi]
    add    edi,4
    add    es:d[edi],edx
    add    edi,4
@@exp0:    add    es:d[edi],edx
    mov    esi,es:[edi]
    mov    bx,CodeSegment
    cmp    es:w[esi+4],0
    jz    @@exp1
    mov    bx,DataSegment
    cmp    es:w[esi+4],1
    jz    @@exp1
    mov    bx,apiCodeSeg
    cmp    es:w[esi+4],2
    jz    @@exp1
    mov    bx,apiDataSeg
    cmp    es:w[esi+4],3
    jz    @@exp1
    or    bx,-1
@@exp1:    mov    es:[esi+4],bx
    add    edi,4
    dec    ebp
    jnz    @@exp0
    pop    es
    assume ds:_cwInit
    pop    ds
;
;Initialise extensions. Written in a bit of a hurry but allows
;additional interupt service code to live in other segments.
;
    push    ds
    mov    ds,mDataSegment
    assume ds:_cwMain
    or    mcbAllocations,-1    ;Enable MCB code.
    ;
    mov    di,offset ExtensionList
@@e0:    cmp    w[di],-1        ;end of the list?
    jz    @@e9
    mov    bp,[di]        ;get pointer to details.
    movzx    ecx,ds:w[bp+4]    ;get patch size.
    sys    GetMemLinear32    ;get some memory.
    push    ds
    mov    ds,DataSegmenti
    assume ds:_cwInit
    mov    iErrorNumber,5
    assume ds:_cwMain
    pop    ds
    jc    InitError
    sys    LockMem32        ;lock the memory.
    jc    InitError
    sys    GetSel        ;get a selector to use for
    push    ds
    mov    ds,DataSegmenti
    assume ds:_cwInit
    mov    IErrorNumber,8    ;the code segment.
    assume ds:_cwMain
    pop    ds
    jc    InitError
    mov    edx,esi
    sys    SetSelDet32        ;set it's base and limit.
    jc    InitError
    push    ecx
    mov    cx,ds:[bp+2]        ;Get code seg size.
    sys    CodeSel        ;convert to executable.
    pop    ecx
    mov    ds:[bp+8+4],bx    ;store it for now.
    mov    ds:[bp+16+4],bx
    mov    ds:[bp+24],bx
    sys    GetSel        ;get a selector to use for data.
    jc    InitError
    sys    SetSelDet32        ;set it's base and limit.
    jc    InitError
    mov    ds:[bp+28],bx    ;store it for now.
    pushm    di,ds,es
    movzx    esi,ds:w[bp+0]    ;get real mode segment base.
    shl    esi,4
    mov    ds,RealSegment
    mov    es,bx
    xor    edi,edi
    db 67h
    rep    movsb
    popm    di,ds,es
    mov    ds:w[bp+32],-1    ;flag installed.
    pushm    di,bp,ds
    mov    es,DataSegment
    mov    ds,ds:[bp+28]

    push    cs
    push    offset @@e1
    push    es:w[bp+12]
    push    es:w[bp+8]
    retf            ;call init routine.
@@e1:    popm    di,bp,ds
    jc    InitError
    add    di,2
    jmp    @@e0
@@e9:    assume ds:_cwInit
    pop    ds

IFDEF DEBUG3
    push    eax
    push    ebx
    push    ecx
    push    es
    push    ds
    mov    ax,KernalZero
    mov    es,ax

    mov    ebx,0b81e0h
    mov    BYTE PTR es:[ebx],'F'
    mov    BYTE PTR es:[ebx+2],'P'
    mov    BYTE PTR es:[ebx+4],' '
    mov    BYTE PTR es:[ebx+6],' '
    mov    BYTE PTR es:[ebx+24],' '
    mov    BYTE PTR es:[ebx+26],' '

    mov    ax,KernalDS        ;Get data descriptor.
    mov    ds,ax
    assume ds:_cwRaw
    movzx    edx,FirstUninitPage
    push    edx
    mov    ecx,edx
    xor    edx,edx
deb3_3:
    rol    ecx,4
    mov    al,cl
    and    al,0fh
    cmp    al,10
    jb    deb3_2
    add    al,7
deb3_2:
    add    al,48
    mov    es:[ebx+edx*2+8],al
    inc    edx
    cmp    edx,8
    jb    deb3_3
    pop    edx

    mov    ecx,200000h
deb3_aloop:
    dec    ecx
;    jne    deb3_aloop
    pop    ds
    pop    es
    pop    ecx
    pop    ebx
    pop    eax
ENDIF

COMMENT !
IFDEF DEBUG3
    push    ds
    push    es
    push    eax
    push    ebx
    push    ecx
    push    edx
    push    edi
    push    ebp

    mov    ax,KernalDS        ;Get data descriptor.
    mov    ds,ax
    assume ds:_cwRaw
    movzx    edi,Page1stReal    ;get linear address.
    shl    edi,4
    mov    ax,KernalZero
    mov    es,ax
    mov    bp,1024
    sub    esp,10
    push    ss
    pop    ds
moo1:
    mov    ecx,es:[edi]
    xor    edx,edx
deb5_3:
    rol    ecx,4
    mov    al,cl
    and    al,0fh
    cmp    al,10
    jb    deb5_2
    add    al,7
deb5_2:
    add    al,48
    mov    BYTE PTR ss:[esp+edx],al
    inc    edx
    cmp    edx,8
    jb    deb5_3

    mov    WORD PTR ss:[esp+8],0a0dh
    mov    edx,esp
    mov    ecx,10
    mov    ebx,1
    mov    ah,40h
    int    21h

    add    di,4        ;next page table entry.
    dec    bp
    jnz    moo1

    add    esp,10
    pop    ebp
    pop    edi
    pop    edx
    pop    ecx
    pop    ebx
    pop    eax
    pop    es
    pop    ds
    jmp    debout1

debout1:
ENDIF
END COMMENT !

;
;We're all done here so switch to main code segment for final re-size and run.
;
    push    mCodeSegment
    push    offset cwOpen
    retf

    .286

@@OldStrat:    ;
    dw ?,?

@@NumXMSHandles:
    db ?

; MED, 09/10/99, increase max XMS size to dword
@@XMSSize:    ;
;    dw ?
    dd    0

Startup    endp


;-------------------------------------------------------------------------------
;
;Something is wrong with this system so print an error message and get out of
;here.
;
InitError    proc    near
;
;Find out if we're in protected mode or not.
;
    .386p
    assume ds:nothing
    cmp    cs:IProtectedMode,0          ; are we in protected mode?

; MED 07/10/97, allow 286 non-crash at this point
;    jz    @@RealMode
    jnz    chkapi
    jmp    @@RealMode
chkapi:

    cmp    cs:apiDataSegi,0    ;API installed?
    jz    @@noAPI
    ;
    mov    ds,cs:mDataSegment
    assume ds:_cwMain
;
;Remove extension patches.
;
    mov    di,offset ExtensionList    ;list of interupt patches.
@@p1:    cmp    w[di+2],-1        ;search for the end of the table so we can restore
    jz    @@p0        ;vectors in reverse order.
    add    di,2
    jmp    @@p1
    ;
@@p0:    mov    bp,w[di]
    cmp    ds:w[bp+32],-1    ;installed?
    jnz    @@p2
    pushm    di,bp
    push    cs
    push    offset @@p3
    push    ds:w[bp+20]
    push    ds:w[bp+16]
    retf
@@p3:    popm    di,bp
@@p2:    sub    di,2
    cmp    di,offset ExtensionList-2
    jnz    @@p0
;
;Remove api exception patches.
;
    cmp    apiExcepPatched,0
    jz    @@pe0
    mov    ax,cs
    push    ax
    mov    ax,offset @@pe0
    push    ax
    mov    ax,dpmiCodeSel
    push    ax
    mov    eax,offset UnPatchExc
    push    ax
    retf
@@pe0:    ;
;
;Remove the API patch.
;
    mov    ds,cs:mDataSegment
    assume ds:_cwMain
    mov    es,apiDataSeg
    assume es:_apiCode
    test    SystemFlags,1
    jz    @@Use32
    mov    dx,es:w[OldIntSys]
    mov    cx,es:w[OldIntSys+2]
    jmp    @@Use0
@@Use32:    mov    edx,es:d[OldIntSys]
    mov    cx,es:w[OldIntSys+4]
@@Use0:    mov    bl,31h
    mov    ax,205h
    int    31h
    mov    es:d[cwIdentity],0
    mov    es:d[cwIdentity+4],0
    assume es:nothing
    ;
@@noAPI:    assume ds:nothing
    cmp    cs:IProtectedType,2    ;DPMI?
    assume ds:_cwInit
    jz    @@DPMI
;
;Make RAW stuff addressable.
;
    cli            ;Don't want interrupts interfering.
    mov    ax,KernalDS        ;Get supervisor data descriptor,
    mov    ds,ax        ;DS,ES,FS,GS,SS must be data with 64k limit
    assume ds:_cwRaw
    mov    ax,KernalZero
    mov    es,ax
;
;Switch to RAW exit code.
;
    push    _cwInit
    push    offset @@6
    mov    ax,KernalCS
    push    ax
    mov    ax,offset RawVCPIRealMode
    push    ax
    retf
@@6:    jmp    @@RealMode
;
;Remove DPMI stuff.
;
    .386
@@DPMI:

    if    0
    assume ds:nothing
    mov    ds,cs:iDataSegment
    assume ds:_cwInit
    mov    ds,mDataSegment
    assume ds:_cwMain
    cmp    d[OldInt21hExec],0
    jz    @@d0
    mov    bl,21h
    mov    dx,w[OldInt21hExec]
    mov    cx,w[OldInt21hExec+2]
    mov    ax,201h
    int    31h
@@d0:
    endif

    assume ds:nothing
    mov    ds,cs:iDataSegment
    assume ds:_cwInit

    cmp    IErrorNumber,0
    jz    @@NoError
    mov    ax,IErrorNumber    ;Get the error number.
    xor    dx,dx
    mov    cx,10
    div    cx
    add    al,'0'
    mov    b[IErrorM00n],al
    add    dl,'0'
    mov    b[IErrorM00n+1],dl
    mov    dx,w[InitErrorList]

    mov    edi,offset DPMIErrRegs
    push    ds
    pop    es
    mov    Real_EDX[edi],edx
    mov    Real_EAX[edi],900h
    mov    Real_DS[edi],_cwInit
    xor    cx,cx        ;No stack parameters.
    mov    bh,ch        ;no flags.
    mov    ax,0300h
    int    31h        ;Use real dpmi service.
;
;Get a pointer to the appropriate error message and print it.
;
    mov    bx,IErrorNumber
    add    bx,bx
    mov    dx,[InitErrorList+bx]

    mov    edi,offset DPMIErrRegs
    push    ds
    pop    es
    mov    Real_EDX[edi],edx
    mov    Real_EAX[edi],900h
    mov    Real_DS[edi],_cwInit
    xor    cx,cx        ;No stack parameters.
    mov    bh,ch        ;no flags.
    mov    ax,0300h
    int    31h        ;Use real dpmi service.

    jmp    @@NoError
    .286
;
;Make sure our data is addressable.
;
@@RealMode:    mov    ax,_cwInit
    mov    ds,ax
    assume ds:_cwInit
;
;Display the "CauseWay error: ??" bit.
;
@@InRealMode:    cmp    IErrorNumber,0
    jz    @@NoError
    mov    ax,IErrorNumber    ;Get the error number.
    xor    dx,dx
    mov    cx,10
    div    cx
    add    al,'0'
    mov    b[IErrorM00n],al
    add    dl,'0'
    mov    b[IErrorM00n+1],dl
    mov    dx,w[InitErrorList]
    mov    ah,9
    int    21h
;
;Get a pointer to the appropriate error message and print it.
;
    mov    bx,IErrorNumber
    add    bx,bx
    mov    dx,[InitErrorList+bx]
    mov    ah,9
    int    21h
;
;Now exit with the error number as the DOS "errorlevel".
;
@@NoError:    mov    ax,IErrorNumber
    mov    ah,4ch
    int    21h
    assume ds:_cwMain
InitError    endp


;-------------------------------------------------------------------------------
;
;Initialise real mode hardware interupt vectors so that control is always passed to protected mode
;even if the interupt occurs in real mode. This simulates the DPMI environment and is essential for
;any program that re-programs IRQ-0 frequency.
;
InitHardwareInts proc near
    .386
    pushm    ds,es
    mov    ax,KernalDS
    mov    ds,ax
    mov    ax,KernalZero
    mov    es,ax
    assume ds:_cwRaw
;    mov    ch,16
;    mov    cl,1ch
;    call    @@0
    mov    ch,17
    mov    cl,23h        ;patch ctrl-break.
    call    @@0
    mov    ch,18
    mov    cl,24h        ;patch critical error.
    call    @@0
    popm    ds,es
    ret
    ;
@@0:    mov    ax,size CallBackStruc
    movzx    bx,ch
    mul    bx
    mov    bx,ax
    add    bx,offset CallBackTable
    pushf
    cli
    mov    CallBackNum[bx],cl    ;set interupt number.
    mov    CallBackFlags[bx],1+2    ;mark call back as used interupt.
    mov    ax,CallBackSize
    movzx    dx,ch
    mul    dx
    mov    si,offset ICallBackList
    add    si,ax        ;index list of calls.
    push    bx
    movzx    bx,cl
    shl    bx,2
    mov    dx,es:[bx]
    mov    cx,es:[bx+2]
    mov    es:[bx],si
    mov    es:w[bx+2],seg _cwRaw
    pop    bx
    mov    w[CallBackReal+2+bx],cx    ;store origional real mode vector.
    mov    w[CallBackReal+bx],dx
    popf
    ret
    assume ds:_cwMain
    .286
InitHardwareInts endp


;-------------------------------------------------------------------------------
CheckProcessor    proc    near
    xor    ax,ax        ;Clear the flags.
    push    ax        ;/
    popf            ;/
    pushf            ;Get the flags back.
    pop    ax        ;/
    and    ax,0F000h        ;Get Bits 11-8
    cmp    ax,0F000h        ;Exist on this processor?
    je    @@9        ;Must be an 8086
    mov    ax,0F000h        ;Setup the flags again.
    push    ax        ;/
    popf            ;/
    pushf            ;Get them back.
    pop    ax        ;/
    and    ax,0F000h        ;Get Bits 11-8
    jz    @@9        ;Valid so must be 80286
    clc
    ret
@@9:    stc
    ret
CheckProcessor    endp


;-------------------------------------------------------------------------------
CheckDOSVersion proc near
    mov    ah,30h
    int    21h        ;Get DOS version.
    mov    DOSVersion,ax
    cmp    al,3        ;3.? or above?
    jc    @@9
    jnz    @@0        ;less means trouble.
    cmp    ah,1
    jc    @@9
@@0:    clc
    ret
@@9:    stc
    ret
CheckDOSVersion endp


;-------------------------------------------------------------------------------
;
;Check for "CAUSEWAY" environment variable and fetch any relevent settings.
;
GetENVStuff    proc    near
    .386
    mov    es,RealEnvSegment
    xor    si,si
@@0:    mov    eax,es:[si]
    cmp    eax,"SUAC"
    jnz    @@1
    mov    eax,es:[si+4]
    cmp    eax,"YAWE"
    jz    @@2
@@1:    inc    si
    cmp    es:b[si-1],0
    jnz    @@1
    cmp    es:b[si],0        ;end of all strings?
    jnz    @@0
    jmp    @@9
    ;
@@2:    ;Found "CAUSEWAY" so have a look at the settings.
    ;
    add    si,8        ;skip to "="
    push    si
@@2_0:    mov    al,es:[si]
    cmp    al,61h        ; 'a'
    jb    @@2_1
    cmp    al,7Ah        ; 'z'
    ja    @@2_1
    and    al,5Fh        ;convert to upper case.
@@2_1:    mov    es:[si],al
    inc    si
    or    al,al
    jnz    @@2_0
    pop    si
    ;
@@3:    cmp    es:b[si]," "
    jnz    @@4
    inc    si
    jmp    @@3
    ;
@@4:    cmp    es:b[si],0        ;end?
    jz    @@9
    ;
    mov    eax,es:[si]
    cmp    eax,"MVON"        ;NOVM?
    jz    @@novm
    cmp    eax,"MXAM"        ;MAXMEM?
    jz    @@maxmem
    cmp    eax,"ATXE"        ;EXTALL?
    jz    @@extall
    cmp    eax,"IMPD"        ;DPMI?
    jz    @@dpmi
    cmp    eax,"PAWS"        ;swap?
    jz    @@swap
    cmp    eax,"MWOL"        ;lowmem?
    jz    @@lowmem
    cmp    eax,"EMIH"        ; himem?
    jz    @@himem
    cmp    eax,"APON"        ; nopass?
    jz    @@nopass
    cmp    eax,":ERP"        ; pre?
    jz    @@pre
    cmp    eax,"EMAN"        ; NAME?
    jz    @@name
    cmp    eax,"1DAP"        ; PAD1?
    jz    @@pad1
    cmp    eax,"XEON"        ; NOEX?
    jz    @@noex
    cmp    eax,"1GIB"        ; BIG1?
    jz    @@big1
    inc    si
    jmp    @@3
    ;
@@nopass:    ; shut off passing of real mode interrupts to protected mode
    add    si,4
    mov    ax,es:[si]
    cmp    ax,"SS"
    jnz    @@3
    add    si,2
    push    ds
    mov    bx,_cwRaw
    mov    ds,bx
    assume ds:_cwRaw
    or    NoPassFlag,-1
    assume ds:_cwMain
    pop    ds
    jmp    @@3

@@big1:    ; specify alternate extended memory size computation
    add    si,4
    push    ds
    mov    bx,_cwRaw
    mov    ds,bx
    assume ds:_cwRaw
    or    Big1Flag,-1
    assume ds:_cwMain
    pop    ds
    jmp    @@3

@@himem:    ;Set amount of physical memory to use.
    ;
    add    si,4
    mov    al,es:[si]
    cmp    al,"M"
    jnz    @@3
    inc    si
    cmp    es:b[si],":"
    jnz    @@3
    inc    si
    xor    edx,edx
@@hm0:    mov    al,es:[si]
    or    al,al
    jz    @@hm1
    cmp    al," "
    jz    @@hm1
    cmp    al,"0"
    jc    @@hm1
    cmp    al,"9"+1
    jnc    @@hm1
    sub    al,"0"
    movzx    eax,al
    add    edx,edx
    mov    ebx,edx
    add    edx,edx
    add    edx,edx
    add    edx,ebx
    add    edx,eax
    inc    si
    jmp    @@hm0
@@hm1:
    cmp    edx,4096*1024
    jnc    @@3

    shl    edx,10        ;turn K into byte's
    shr    edx,12        ;get number of pages.
    push    ds
    mov    bx,_cwRaw
    mov    ds,bx
    assume ds:_cwRaw
    mov    d[MaxMemPhys],edx
    assume ds:_cwMain
    pop    ds
    jmp    @@3
    ;
@@extall:    ;Set flag to use all extended memory.
    ;
    add    si,4
    mov    ax,es:[si]
    cmp    ax,"LL"
    jnz    @@3
    add    si,2
    push    ds
    mov    bx,_cwRaw
    mov    ds,bx
    assume ds:_cwRaw
    or    ExtALLSwitch,-1
    assume ds:_cwMain
    pop    ds
    jmp    @@3
    ;
@@novm:    ;They want to disable VM.
    ;
    add    si,4
    push    ds
    mov    bx,_cwInit
    mov    ds,bx
    assume ds:_cwInit
    or    NoVMSwitch,-1
    assume ds:_cwMain
    pop    ds
    jmp    @@3
    ;
@@maxmem:    ;Want to set maximum linear address space size.
    ;
    add    si,4
    mov    ax,es:[si]
    cmp    ax,"ME"
    jnz    @@3
    add    si,2
    cmp    es:b[si],":"
    jnz    @@3
    inc    si
    xor    edx,edx
@@mm0:    mov    al,es:[si]
    or    al,al
    jz    @@mm1
    cmp    al," "
    jz    @@mm1
    cmp    al,"0"
    jc    @@mm1
    cmp    al,"9"+1
    jnc    @@mm1
    sub    al,"0"
    movzx    eax,al
    add    edx,edx
    mov    ebx,edx
    add    edx,edx
    add    edx,edx
    add    edx,ebx
    add    edx,eax
    inc    si
    jmp    @@mm0
@@mm1:
    cmp    edx,4096
    jnc    @@3

    shl    edx,20        ;turn Meg into byte's
    push    ds
    mov    bx,_cwRaw
    mov    ds,bx
    assume ds:_cwRaw
    mov    d[MaxMemLin],edx
    assume ds:_cwMain
    pop    ds
    jmp    @@3

@@pre:    ;Want to set preallocate amount
    ;
    add    si,4
    xor    edx,edx
@@pr0:    mov    al,es:[si]
    or    al,al
    jz    @@pr1
    cmp    al," "
    jz    @@pr1
    cmp    al,"0"
    jc    @@pr1
    cmp    al,"9"+1
    jnc    @@pr1
    sub    al,"0"
    movzx    eax,al
    add    edx,edx
    mov    ebx,edx
    add    edx,edx
    add    edx,edx
    add    edx,ebx
    add    edx,eax
    inc    si
    jmp    @@pr0
@@pr1:
    cmp    edx,4096
    jnc    @@3

    shl    edx,20        ;turn Meg into byte's
    push    ds
    mov    bx,_cwRaw
    mov    ds,bx
    assume ds:_cwRaw
    mov    d[PreAllocSize],edx
    assume ds:_cwMain
    pop    ds
    jmp    @@3

@@pad1:
    mov    Pad1Flag,1
    add    si,4
    jmp    @@3

@@noex:
    mov    NoEXECPatchFlag,1
    add    si,4
    jmp    @@3

@@dpmi:    ;They want to force DPMI use if possible.
    ;
    mov    ProtectedForce,1
    add    si,4
    jmp    @@3
    ;
@@swap:    ;They want to specify the swap drive.
    ;
    add    si,4
    cmp    es:b[si],":"
    jnz    @@3
    inc    si
    mov    di,offset VMMDrivPath1
    push    ds
    mov    bx,_cwInit
    mov    ds,bx
    assume ds:_cwInit
@@s0:    mov    al,es:[si]
    mov    [di],al
    inc    si
    inc    di
    or    al,al
    jz    @@s1

    cmp    al,";"    ; MED 02/25/96
    je    @@s1

    cmp    al," "
    jnz    @@s0
@@s1:    mov    b[di-1],0
    assume ds:_cwMain
    pop    ds
    dec    si
    jmp    @@3
    ;
@@name:    ; Specify the swap name.
    ;
    add    si,4
    cmp    es:b[si],":"
    jnz    @@3
    inc    si
    mov    di,offset DesiredVMMName
    push    ds
    mov    bx,_cwRaw
    mov    ds,bx
    assume ds:_cwRaw
    xor    dx,dx
@@n0:    mov    al,es:[si]
    mov    [di],al
    inc    si
    inc    di
    or    al,al
    jz    @@n1
    inc    dx
    cmp    dx,12
    ja    @@n1        ; don't allow more than 12 chars in file name

    cmp    al,";"    ; MED 02/25/96
    je    @@n1

    cmp    al," "
    jnz    @@n0
@@n1:    mov    b[di-1],0
    assume ds:_cwMain
    pop    ds
    dec    si
    jmp    @@3
    ;
@@lowmem:    ;They want to specify low memory retention.
    ;
    add    si,4
    mov    ax,es:[si]
    cmp    ax,"ME"
    jnz    @@3
    add    si,2
    cmp    es:b[si],":"
    jnz    @@3
    inc    si
    xor    edx,edx
@@lm0:    mov    al,es:[si]
    or    al,al
    jz    @@lm1
    cmp    al," "
    jz    @@lm1
    cmp    al,"0"
    jc    @@lm1
    cmp    al,"9"+1
    jnc    @@lm1
    sub    al,"0"
    movzx    eax,al
    add    edx,edx
    mov    ebx,edx
    add    edx,edx
    add    edx,edx
    add    edx,ebx
    add    edx,eax
    inc    si
    jmp    @@lm0
    ;
@@lm1:    shl    edx,10-4        ;turn K into para's
    push    ds
    mov    bx,_cwRaw
    mov    ds,bx
    assume ds:_cwRaw
    movzx    ebx,w[CONVSaveSize]
    add    edx,ebx
    cmp    edx,65535
    jc    @@lm2
    mov    edx,65535
@@lm2:    mov    w[CONVSaveSize],dx    ;set new size.
    assume ds:_cwMain
    pop    ds
    ;
    jmp    @@3
    ;
@@9:    ;Now look for TEMP.
    ;
    xor    si,si        ;start at the beginning.
@@temp2:    mov    eax,es:[si]
    cmp    eax,"PMET"
    jz    @@temp0
@@temp1:    inc    si
    cmp    es:b[si-1],0
    jnz    @@temp1
    cmp    es:b[si],0
    jz    @@temp9
    jmp    @@temp2
    ;
@@temp0:    add    si,4
    cmp    es:b[si],"="
    jnz    @@temp9
    inc    si
    push    ds
    mov    bx,_cwInit
    mov    ds,bx
    mov    di,offset VMMDrivPath2
@@temp3:    mov    al,es:[si]
    mov    [di],al
    inc    si
    inc    di
    or    al,al
    jz    @@temp4
    cmp    al," "
    jnz    @@temp3
@@temp4:    mov    b[di-1],0
    pop    ds
@@temp9:    ;
    ;Look for TMP
    ;
    xor    si,si        ;start at the beginning.
@@tmp2:    mov    eax,es:[si]
    cmp    eax,"=PMT"
    jz    @@tmp0
@@tmp1:    inc    si
    cmp    es:b[si-1],0
    jnz    @@tmp1
    cmp    es:b[si],0
    jz    @@tmp9
    jmp    @@tmp2
    ;
@@tmp0:    add    si,4
    push    ds
    mov    bx,_cwInit
    mov    ds,bx
    mov    di,offset VMMDrivPath3
@@tmp3:    mov    al,es:[si]
    mov    [di],al
    inc    si
    inc    di
    or    al,al
    jz    @@tmp4
    cmp    al," "
    jnz    @@tmp3
@@tmp4:    mov    b[di-1],0
    pop    ds
@@tmp9:    ;
    ret
    .286
GetENVStuff    endp


;-------------------------------------------------------------------------------
GetEXECName    proc    near
    .386
@@0:    mov    es,RealEnvSegment
    xor    si,si
@@1:    mov    al,es:[si]        ;Get a byte.
    inc    si        ;/
    or    al,al        ;End of a string?
    jnz    @@1        ;keep looking.
    mov    al,es:[si]        ;Double zero?
    or    al,al        ;/
    jnz    @@1        ;keep looking.
    add    si,3        ;Skip last 0 and word count.
    mov    di,offset MainExec
    mov    bx,_cwInit
    mov    fs,bx
    mov    bx,offset VMMDrivPath4
    mov    cx,128
    mov    dx,bx
    pushm    ds,ds,es
    popm    es,ds
@@2:    movsb
    mov    al,[si-1]
    mov    fs:[bx],al
    inc    bx
    cmp    b[si-1],"\"
    jnz    @@2_0
    mov    dx,bx
    dec    dx
@@2_0:    cmp    b[si-1],0        ;got to the end yet?
    jz    @@3
    dec    cx
    jnz    @@2
@@3:    mov    bx,dx
    mov    fs:b[bx],0        ;terminate VMM path.

COMMENT !
; MED 10/10/96
    cmp    bx,offset VMMDrivPath4
    jne    genexit            ; non-null path
    mov    BYTE PTR fs:[bx],'.'    ; null path, give a valid one of '.\'
    mov    BYTE PTR fs:[bx+1],'\'
    mov    BYTE PTR fs:[bx+2],0
END COMMENT !

genexit:
    pop    ds
    pushm    ds,ds
    popm    es,fs
    ret
    .286
GetEXECName    endp


;-------------------------------------------------------------------------------
GetSystemFlags    proc    near
    push    ds
    mov    dx,offset MainExec
    mov    ax,3d00h        ;open, read only.
    int    21h
    jc    @@5
    push    cs
    pop    ds
    assume ds:_cwInit
    mov    bx,ax
    mov    dx,offset IExeSignature    ;somewhere to put the info.
    mov    cx,1bh        ;size of it.
    mov    ah,3fh
    int    21h
    jc    @@4
    cmp    ax,1bh        ;did we read right amount?
    jnz    @@4
    cmp    w[IExeSignature],'ZM'    ;Normal EXE?
    jnz    @@4
    mov    ax,w[IExeLength+2]    ;get length in 512 byte blocks

; MED 01/17/96
    cmp    WORD PTR [IExeLength],0
    je    medexe2        ; not rounded if no modulo

    dec    ax        ;lose 1 cos its rounded up

medexe2:
    add    ax,ax        ;mult by 2
    mov    dh,0
    mov    dl,ah
    mov    ah,al
    mov    al,dh        ;mult by 256=*512
    add    ax,w[IExeLength]    ;add length mod 512
    adc    dx,0        ;add any carry to dx
    mov    cx,ax
    xchg    cx,dx        ;swap round for DOS.
    mov    ax,4200h        ;set absolute position.
    int    21h
    mov    dx,offset INewHeader    ;somewhere to put the info.
    mov    cx,size NewHeaderStruc    ;size of it.
    mov    ah,3fh
    int    21h
    jc    @@4
    or    ax,ax        ;end of the file?
    jz    @@SetRUN
    cmp    ax,size NewHeaderStruc    ;did we read right amount?
    jnz    @@4
    cmp    w[INewHeader],'P3'    ;ID ok?
    jnz    @@4
    mov    si,offset INewHeader
    mov    ax,w[NewFlags+si]    ;Copy main flags.
    mov    cx,w[NewFlags+2+si]
    pop    ds
    push    ds
    assume ds:_cwMain
    mov    w[SystemFlags],ax
    mov    w[SystemFlags+2],cx
    mov    dx,_cwRaw
    mov    ds,dx
    assume ds:_cwRaw
    mov    w[RawSystemFlags],ax
    mov    w[RawSystemFlags+2],cx
    .386
    mov    dx,_cwDPMIEMU
    mov    ds,dx
    assume ds:_cwDPMIEMU
    mov    w[DpmiEmuSystemFlags],ax
    mov    w[DpmiEmuSystemFlags+2],cx
    mov    dx,_apiCode
    mov    ds,dx
    assume ds:_apiCode
    mov    w[apiSystemFlags],ax
    mov    w[apiSystemFlags+2],cx
    .286
    assume ds:_cwMain
@@4:    mov    ax,3e00h
    int    21h
    jmp    @@5

;
;Nothing on the end of the extender so replace the exec name with first
;command line argument and shuffle everything else down. Allows CW32 to be used
;to run 32-bit programs not attatched to it from the command line.
;
@@SetRUN:    mov    ax,3e00h        ;close file, we don't need it.
    int    21h
    mov    ax,_cwMain
    mov    ds,ax
    assume ds:_cwMain
    push    es
    mov    es,RealPSPSegment
    mov    si,80h
    xor    ch,ch
    mov    cl,es:b[si]
    or    cx,cx
    jz    @@sr5
    inc    si
    mov    di,offset MainExec    ;default to storeing program name.
    ;
    ;Skip white space.
    ;
@@sr0:    mov    al,es:[si]
    cmp    al," "
    jnz    @@sr1
    inc    si
    dec    cx
    jnz    @@sr0
    jmp    @@sr3
    ;
    ;Get program name.
    ;
@@sr1:    mov    al,es:[si]
    cmp    al," "
    jz    @@sr2
    mov    es:b[si],' '
    mov    [di],al
    inc    si
    inc    di
    dec    cx
    jnz    @@sr1
@@sr2:    mov    b[di],0
@@sr3:    pop    es
;
;Clean up the command line, ie, remove any spaces created by removeing name.
;
    push    es
    mov    es,RealPSPSegment
    mov    si,80h
    xor    ch,ch
    mov    cl,es:b[si]
    or    cx,cx
    jz    @@cl3
    inc    si
    mov    di,si
@@cl0:    cmp    es:b[si],' '
    jnz    @@cl1
    inc    si
    dec    cx
    jnz    @@cl0
@@cl1:    jcxz    @@cl2
    push    cx
    push    ds
    push    es
    pop    ds
    rep    movsb        ;Copy it down.
    pop    ds
    pop    cx
@@cl2:    mov    es:b[80h],cl        ;Store new length.
@@cl3:    xor    ch,ch
    add    cx,81h
    mov    si,cx
    mov    es:b[si],13        ;Terminate it correctly.
@@sr5:    pop    es
    ;
    assume ds:_cwMain
@@5:    pop    ds
    ret
GetSystemFlags    endp


;-------------------------------------------------------------------------------
GetProtectedType proc near
;
;Find out what protected mode environments are available.
;
    call    ChkDPMI        ;32 bit DPMI server present?
    jc    @@0
    or    ProtectedFlags,1
@@0:    call    ChkVCPI        ;VCPI >= v1.0 present?
    jc    @@1
    or    ProtectedFlags,2
@@1:    call    ChkRAW        ;Running in real mode?
    jc    @@2
    or    ProtectedFlags,4
@@2:    ret
GetProtectedType endp


;-------------------------------------------------------------------------------
SetProtectedType proc near
    cmp    ProtectedForce,0
    jz    @@NoDPMIForce
    test    ProtectedFlags,1
    jnz    @@2
    ;
@@NoDPMIForce:    test    ProtectedFlags,4
    jz    @@1
    mov    ProtectedType,0    ;Use real mode.
    jmp    @@3
@@1:    test    ProtectedFlags,2
    jz    @@2
    mov    ProtectedType,1    ;Use VCPI.
    jmp    @@3
@@2:    mov    ProtectedType,2    ;Use DPMI.
@@3:    push    es
    mov    ax,_cwInit
    mov    es,ax
    assume es:_cwInit
    mov    ax,ProtectedType
    mov    es:IProtectedType,ax
    assume es:nothing
    pop    es
    ret
SetProtectedType endp


;-------------------------------------------------------------------------------
ChkDPMI    proc    near
;
;See if DPMI server present.
;
    mov    ax,1687h        ;DPMI instalation check.
    int    2fh
    or    ax,ax        ;None-zero means its not there.
    jnz    @@9
    test    w[SystemFlags],1
    jz    @@Use32Bit21
    jmp    @@Use16Bit21
@@Use32Bit21:    test    bx,1        ;Must offer 32 bit support.
    jz    @@9
@@Use16Bit21:    clc
    ret
    ;
@@9:    stc
    ret
ChkDPMI    endp


;-------------------------------------------------------------------------------
;
; The following routine checks to see if a VCPI master program is installed.
; If one is not, the carry flag is set on return
; If one is, the version info is stored and the carry flag is cleared on return
;
ChkVCPI    proc    near
    pushm    ax,bx,es
    xor    ax,ax
    mov    es,ax
    mov    si,es:[67h*4]    ;Check a handler exists.
    mov    di,es:[(67h*4)+2]
    mov    ax,si
    or    ax,di
    jnz    @@IsHandler
    cli
    mov    es:w[67h*4],offset @@DummyIRET
    mov    es:w[(67h*4)+2],cs
@@IsHandler:    pushm    si,di
    mov    ax,0DE00h        ;Get VCPI installed state
    int    67h
    popm    si,di
    mov    es:[67h*4],si    ;Check a handler exists.
    mov    es:[(67h*4)+2],di
    sti
    ;
    cmp    al,0
    jne    @@NotThere
    or    bx,3030h        ;Turn to ASCII
    cmp    bh,'1'
    jc    @@NotThere
    mov    ax,si
    or    ax,di        ;Only pretending to be their?
    jz    @@HopeThere
    ;
    call    @@ChkEMS        ;Make sure EMS is in first
    jc    @@HopeThere        ;EMS not in.
    call    @@GrabPage        ;Make sure EMS initiated
@@HopeThere:    clc            ;Set for no error
    jmp    @@Done
@@NotThere:    stc
@@Done:    popm    ax,bx,es
    ret
@@DummyIRET:    iret
;
; The following routine checks to see if an EMM is installed.
; If one is not, the carry flag is set on return
; If one is, the carry flag is cleared on return
;
@@ChkEMS:    pushm    ax,bx,dx,es
    pushm    ds,cs
    pop    ds
    mov    dx,offset @@EMSName    ;Device driver name
    mov    ah,3Dh        ;Open file
    mov    al,0        ;Access/file sharing mode
    int    21h
    pop    ds
    jc    @@NotThere2
    mov    bx,ax        ;Put handle in proper place
    mov    ah,44h        ;IOCTL
    mov    al,07h        ;Get output status
    int    21h
    jc    @@NotThere1
    cmp    al,0FFh
    jne    @@NotThere1
    mov    ah,3Eh        ;Close file
    int    21h
    clc            ;Set for no error
    jmp    @@Done1
@@NotThere1:    mov    ah,3Eh        ;Close file
    int    21h
@@NotThere2:    stc
@@Done1:    popm    ax,bx,dx,es
    ret
;
; This function allocates an EMS page, and then releases it.  This is
; done to make sure the EMS driver has switched the CPU to V86 mode.
; On return, the carry is set if there was any problem using the EMS
; functions.  Carry is clear otherwise.
;
@@GrabPage:    mov    ah,43h        ;Allocate pages
    mov    bx,1        ;Get 1 page (16K)
    int    67h
    cmp    ah,0        ;Was there an error?
    jne    @@GPErr        ;Yes, so exit
    mov    ah,45h        ;Release EMS handle
    int    67h
    cmp    ah,0        ;Was there an error?
    jne    @@GPErr        ;Yes, so exit
    clc            ;Mark for no error
    jmp    @@GPEnd
@@GPErr:    stc
@@GPEnd:    ret
;
@@EMSName    DB 'EMMXXXX0',0
ChkVCPI    endp


;-------------------------------------------------------------------------------
ChkRAW    proc    near
;
;Can we run on this machine.
;
    .286
    smsw    ax
    and    ax,1             ; are we in protected mode?
    jnz    @@9
    clc
    ret
@@9:    stc
    ret
ChkRAW    endp


;-------------------------------------------------------------------------------
MakeDesc    proc    near
;
;Build a segment descriptor.
;
;On Entry:-
;
;ES:DI    - Descriptor entry to use.
;ESI    - Linear base to set.
;ECX    - limit in bytes.
;AL    - Code size bit.
;AH    - Present/PL/memory|system/type bits.
;
    .386
    pushad
    and    di,not 7        ;lose RPL & TI
    cmp    ecx,0100000h      ; see if we need to set g bit
    jc    @@0
    shr    ecx,12           ; div by 4096
    or    al,80h           ; set g bit
@@0:    mov    es:[di],cx        ;store low word of limit.
    shr    ecx,16
    or    cl,al
    mov    es:[di+6],cl        ;store high bits of limit and gran/code size bits.
    mov    es:[di+2],si        ;store low word of linear base.
    shr    esi,16
    mov    bx,si
    mov    es:[di+4],bl        ;store mid byte of linear base.
    mov    es:[di+7],bh        ;store high byte of linear base.
    mov    es:[di+5],ah        ;store pp/dpl/dt/type bits.
    popad
    ret
MakeDesc    endp


;-------------------------------------------------------------------------------
;
;Build a segment descriptor.
;
;On Entry:-
;
;ES:DI    - Descriptor entry to use.
;ESI    - Linear base to set.
;ECX    - limit in bytes.
;AL    - Code size bit.
;AH    - Present/PL/memory|system/type bits.
;
MakeDesc2    proc    near
    .386
    pushad
    and    edi,not 7        ;lose RPL & TI
    cmp    ecx,0100000h      ; see if we need to set g bit
    jc    @@0
    shr    ecx,12           ; div by 4096
    or    al,80h           ; set g bit
@@0:    mov    es:[edi],cx        ;store low word of limit.
    shr    ecx,16
    or    cl,al
    mov    es:[edi+6],cl    ;store high bits of limit and gran/code size bits.
    mov    es:[edi+2],si    ;store low word of linear base.
    shr    esi,16
    mov    bx,si
    mov    es:[edi+4],bl    ;store mid byte of linear base.
    mov    es:[edi+7],bh    ;store high byte of linear base.
    mov    es:[edi+5],ah    ;store pp/dpl/dt/type bits.
    popad
    ret
MakeDesc2    endp


;-------------------------------------------------------------------------------
;
;Dummy routine to call so that IDT value is re-loaded.
;
IDTFlush    proc    far
    ret
IDTFlush    endp


;-------------------------------------------------------------------------------
Bordi    proc    near
    pushm    ax,dx
    mov    ah,al
    mov    dx,3dah
    in    al,dx
    mov    dl,0c0h
    mov    al,11h
    out    dx,al
    mov    al,ah
    out    dx,al
    mov    al,20h
    out    dx,al
    popm    ax,dx
    ret
Bordi    endp


;-------------------------------------------------------------------------------
;
;Initialisation specific data.
;
apiDataSegi    dw 0
IProtectedMode    db 0
IProtectedType    dw 0
DPMISwitch    dw ?,?
dpmiSelBase    dd 0
dpmiCodeSel    dw ?
dpmiDataSel    dw ?
;
iCodeSegment    dw InitCS
mCodeSegment    dw MainCS
iDataSegment    dw InitDS
mDataSegment    dw MainDS
iStackSegment    dw MainSS
iPSPSegment    dw MainPSP
iENVSegment    dw MainENV
iRealSegment    dw KernalZero
;
INewHeader    NewHeaderStruc <>    ;make space for a header.
;
IExeSignature    db ?    ;00 Identifier text.
    db ?    ;01 /
IExeLength    dw ?    ;02 Length of file MOD 512
    dw ?    ;04 Length of file in 512 byte blocks.
IExeRelocNum    dw ?    ;06 Number of relocation items.
IExeHeaderSize    dw ?    ;08 Length of header in 16 byte paragraphs.
IExeMinAlloc    dw ?    ;0A Minimum number of para's needed above program.
IExeMaxAlloc    dw ?    ;0C Maximum number of para's needed above program.
IExeStackSeg    dw ?    ;0E Segment displacement of stack module.
IExeEntrySP    dw ?    ;10 value for SP at entry.
IExeCheckSum    dw ?    ;12 Check sum...
IExeEntryIP    dw ?    ;14 Contents of IP at entry.
IExeEntryCS    dw ?    ;16 Segment displacement of CS at entry.
IExeRelocFirst    dw ?    ;18 First relocation item offset.
IExeOverlayNum    db ?    ;1A Overlay number.
;
IErrorNumber    dw 0
InitErrorList    dw IErrorM00,IErrorM01,IErrorM02,IErrorM03,IErrorM04,IErrorM05,IErrorM06,IErrorM07
    dw IErrorM08,IErrorM09
IErrorM00    db 'CauseWay error '
IErrorM00n    db '00 : $'
IErrorM01    label byte
    if ENGLISH
    db 'Unable to re-size program memory block.',13,10,'$'
    elseif SPANISH
    db "Incapaz de redimensionar el bloque de memoria del programa",13,10,"$"
    endif
IErrorM02    label byte
    if ENGLISH
    db '386 or better required.',13,10,'$'
    elseif SPANISH
    db "Se requiere un 386 o superior.",13,10,"$"
    endif
IErrorM03    label byte
    if ENGLISH
    db 'Non-standard protected mode program already active.',13,10,'$'
    elseif SPANISH
    db "Programa en modo protegido no estandar activado.",13,10,"$"
    endif
IErrorM04    label byte
    if ENGLISH
    db 'DOS 3.1 or better required.',13,10,'$'
    elseif SPANISH
    db "DOS 3.1 o superior requerido.",13,10,"$"
    endif
IErrorM05    label byte
    if ENGLISH
    db 'Not enough memory for CauseWay.',13,10,'$'
    elseif SPANISH
    db "Memoria insuficiente para CauseWay.",13,10,"$"
    endif
IErrorM06    label byte
    if ENGLISH
    db 'VCPI failed to switch into protected mode.',13,10,'$'
    elseif SPANISH
    db "VCPI fallo al cambiar a modo protegido.",13,10,"$"
    endif
IErrorM07    label byte
    if ENGLISH
    db 'Unable to control A20.',13,10,'$'
    elseif SPANISH
    db "Capaz de controlar A20.",13,10,"$"
    endif
IErrorM08    label byte
    if ENGLISH
    db 'Selector allocation error.',13,10,'$'
    elseif SPANISH
    db "Error de asignacion del selector.",13,10,"$"
    endif
IErrorM09    label byte
    if ENGLISH
    db 'DPMI failed to switch to protected mode.',13,10,'$'
    elseif SPANISH
    db "DPMI fallo al cambiar a modo protegido.",13,10,"$"
    endif
;
IFDEF PERMNOVM
NoVMSwitch    db 1
ELSE
NoVMSwitch    db 0
ENDIF

VMMDrivPath1    db 128 dup (0)    ;used by CAUSEWAY=SWAP:?:\??
VMMDrivPath2    db 128 dup (0)    ;used by TEMP=
VMMDrivPath3    db 128 dup (0)    ;used by TMP=
VMMDrivPath4    db 128 dup (0)    ;used by current path.
VMMDrivPath5    db 128 dup (0)    ;used by boot drive.
    db -1
;
DPMIErrRegs    db size RealRegsStruc dup (0)
;
_cwInit    ends


;=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
;
;End marker so we know what to resize program memory size to initialy.
;
_cwEnd    segment para public 'end marker'
_cwEnd    ends

    end    Startup