Leaked source code of windows server 2003
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

4007 lines
97 KiB

page ,160
title bios system initialization
;
;----------------------------------------------------------------------------
;
; Modification history
;
; 26-Feb-1991 sudeepb Ported for NT DOSEm
;----------------------------------------------------------------------------
break macro ; dummy empty macro
endm
include version.inc
include biosseg.inc
include sysvar.inc
include curdir.inc
include pdb.inc
include exe.inc
include sf.inc
include arena.inc
include syscall.inc
include devsym.inc
include ioctl.inc
include biostruc.inc
include dossym.inc
include dosmac.inc
include mult.inc
include dossvc.inc
include dbgsvc.inc
include cmdsvc.inc
include xmssvc.inc
include vint.inc
Bios_Code segment
extrn BCode_start:near
extrn BCode_end:near
extrn seg_reinit:far
Bios_Code ends
include devmark.inc
include cputype.inc
true equ 0ffffh
false equ 0
cr equ 13
lf equ 10
tab equ 9
;multMULT equ 4ah
multMULTGETHMAPTR equ 1
multMULTALLOCHMA equ 2
stacksw equ true ;include switchable hardware stacks
mycds_size equ 71 ; size of curdir_list. if it is not
;the same, then will generate compile error.
if DEBUG ; BUGBUG - Jeez, remove this!
dossize equ 0b200h
else
dossize equ 0a000h
endif
if ibmjapver
noexec equ true
else
noexec equ false
endif
; if mycds_size <> curdirlen,then force a compilatiaon error.
if mycds_size ne curdirlen
%out !!! sysinit1 compilation failed. different cds size !!!
.errne mycds_size eq curdirlen
endif
if not ibmjapver
extrn re_init:far
endif
ifdef TAIWAN
extrn cdosinit:near
endif
;---------------------------------------
Bios_Data segment
;equates for main stack and stack initialization program
if stacksw
extrn NextStack:dword ; Win386 Instance table stuff
extrn IT_StackLoc:dword ; we have to plug in so that our
extrn IT_StackSize:word ; stacks can be instanced
entrysize equ 8
mincount equ 8
defaultcount equ 9
maxcount equ 64
minsize equ 32
defaultsize equ 128
maxsize equ 512
allocbyte equ 0
intlevel equ 1
savedsp equ 2
savedss equ 4
newsp equ 6
free equ 0
allocated equ 1
overflowed equ 2
clobbered equ 3
; external variables in ibmbio for int19h handling rouitne.
extrn int19sem:byte
irp aa,<02,08,09,0a,0b,0c,0d,0e,70,72,73,74,76,77>
extrn int19old&aa:dword
endm
endif
;---------------------------------------
; external variable defined in ibmbio module for multi-track
multrk_on equ 10000000b ;user spcified mutitrack=on,or system turns
; it on after handling config.sys file as a
; default value,if multrk_flag = multrk_off1.
multrk_off1 equ 00000000b ;initial value. no "multitrack=" command entered.
multrk_off2 equ 00000001b ;user specified multitrack=off.
extrn multrk_flag:word
;
;SR; Win386 present flag
;
extrn IsWin386:BYTE
;
;SR; Added for SetFocus routine for WIN386 support
;
extrn V86_Crit_SetFocus:far
extrn xms:dword ; entry point for xms driver
extrn inHMA:byte ; flag meaning we're running high
extrn FreeHMAPtr:word
extrn MoveDOSIntoHMA:dword
extrn SysinitPresent:byte
extrn DemInfoFlag:byte
extrn spc_mse_int10:dword
extrn int29Perf:dword
extrn outchr:near
Bios_Data ends
; NTVDM 16-Sep-1992 Jonle
; Softpc Kbd, mouse, emm drivers
SpcKbdSeg segment
extrn InstSpcKbd:near
extrn SpcKbdBeg:byte
extrn SpcKbdEnd:byte
extrn int10h_vector:near
SpcKbdSeg ends
SpcMseSeg segment
extrn InstSpcMse:near
extrn SpcMseBeg:byte
extrn SpcMseEnd:byte
SpcMseSeg ends
SpcEmmSeg segment
extrn InitSpcEmm:near
extrn SpcEmmBeg:byte
extrn SpcEmmEnd:byte
extrn SI_end:byte
SpcEmmSeg ends
sysinitseg segment
assume cs:sysinitseg, ds:nothing,es:nothing,ss:nothing
extrn badcom:byte
extrn condev:byte
extrn auxdev:byte
extrn prndev:byte
extrn commnd:byte
extrn devmark_addr:word
extrn setdevmarkflag:byte
extrn pathstring:byte
extrn print:near
extrn int24:near
extrn mem_err:near
extrn doconf:near
extrn multi_pass:near
extrn badload:near
extrn error_line:near
extrn ShrinkUMB:near
extrn UnlinkUMB:near ;M002
extrn AllocUMB:near
extrn toomanydrivesmsg:byte ; M029
;NTVDM
extrn MseDev:byte ; internal mouse driver name
extrn AllocUMBLow:near ; mem alloc for new internal drivers
extrn bEchoConfig:byte
extrn config:byte
public current_dos_location
public device_list
public sysi_country
public memory_size
public default_drive
public buffers
public files
public num_cds
public sysinit
public cntryfilehandle
public command_line
if stacksw ; internal stack information
public stack_count
public stack_size
public stack_addr
endif
public dosinfo
public fcbs
public keep
public confbot
public alloclim
public zero
public sepchr
public count
public chrptr
public org_count
public bufptr
public memlo
public prmblk
public memhi
public ldoff
public area
public packet
public unitcount
public break_addr
public bpb_addr
public drivenumber
public config_size
public install_flag
public com_level
public cmmt
public cmmt1
public cmmt2
public cmd_indicator
public linecount
public showcount
public buffer_linenum
public donotshownum
public h_buffers
public configmsgflag
public do_install_exec
public multi_pass_id
public temp_bcode_seg
public seg_reinit_ptr
public toomanydrivesflag ; M029
sysinit$:
if stacksw
.sall
; interrupt level 2, 3, 4, 5, 6, 7,(10, 11, 12, 14, 15 - at level)
; should follow the standard interrupt sharing scheme which has
; a standard header structure.
; fyi, the following shows the relations between
; the interrupt vector and interrupt level.
; vec(hex) 2 8 9 a b c d e 70 72 73 74 76 77
; lvl(deci) 9 0 1 2 3 4 5 6 8 10 11 12 14 15
; msstack module modifies the following interrupt vectors
; to meet the standard interrupt sharing standard;
; a, b, c, d, e, 72, 73, 74, 76, 77.
; also, for interrupt level 7 and 15, the firstflag in a standard header
; should be initialized to indicat whether this interrupt handler is
; the first (= 80h) or not. the firstflag entry of int77h's
; program header is initialized in this module.
; firstflag is only meaningful for interrupt level 7 and 15.
;
; user specifies the number of stack elements - default = 9
; minimum = 8
; maximum = 64
;
; intercepts asynchronous hardware interrupts only
;
; picks a stack from pool of stacks and switches to it
;
; calls the previously saved interrupt vector after pushing flags
;
; on return, returns the stack to the stack pool
;
; this is a modification of stacks:
; 1. to fix a bug which was causing the program to take up too much space.
; 2. to dispense stack space from hi-mem first rather than low-mem first.
; . clobbers the stack that got too big instead of innocent stack
; . allows system to work if the only stack that got too big was the most
; deeply nested one
; 3. disables nmi interrupts while setting the nmi vector.
; 4. double checks that a nested interrupt didn't get the same stack.
; 5. intercepts ints 70, 72-77 for pc-ats and other future products
even
dw 0 ; spare field but leave these in order
stackcount dw 0
stackat dw 0
stacksize dw 0
stacks dw 0
dw 0
firstentry dw stacks
lastentry dw stacks+(defaultcount*entrysize)-entrysize
nextentry dw stacks+(defaultcount*entrysize)-entrysize
; these are the individual interrupt handlers
assume ds:nothing,es:nothing,ss:nothing
public int02
public old02
old02 dd 0
int02 proc far
;; NTVDM support for pc convertable is NOT NEEDED 10-Aug-1992 Jonle
;;
;; *********************************************************************
;;
;; this is special support for the pc convertible / nmi handler
;;
;; on the pc convertible, there is a situation where an nmi can be
;; caused by using the "out" instructions to certain ports. when this
;; occurs, the pc convertible hardware *guarantees* that **nothing**
;; can stop the nmi or interfere with getting to the nmi handler. this
;; includes other type of interrupts (hardware and software), and
;; also includes other type of nmi's. when any nmi has occured,
;; no other interrtupt (hardware, software or nmi) can occur until
;; the software takes specific steps to allow further interrupting.
;;
;; for pc convertible, the situation where the nmi is generated by the
;; "out" to a control port requires "fixing-up" and re-attempting. in
;; otherwords, it is actually a "restartable exception". in this
;; case, the software handler must be able to get to the stack in
;; order to figure out what instruction caused the problem, where
;; it was "out"ing to and what value it was "out"ing. therefore,
;; we will not switch stacks in this situation. this situation is
;; detected by interrogating port 62h, and checking for a bit value
;; of 80h. if set, *****do not switch stacks*****.
;;
;; *********************************************************************
;
; push ax
; push es
; mov ax,0f000h
; mov es,ax
; cmp byte ptr es:[0fffeh],mdl_convert ;check if convertible
; pop es
; jne normal02
;
; in al,62h
; test al,80h
; jz normal02
;
;special02:
; pop ax
; jmp dword ptr old02
;
;normal02:
; pop ax
;
call do_int_stacks
dw old02
int02 endp
public int08
public old08
old08 dd 0
int08 proc far
call do_int_stacks
dw old08
int08 endp
public int09
public old09
old09 dd 0
int09 proc far
; keyboard interrupt must have a three byte jump, a nop and a zero byte
; as its first instruction for compatibility reasons
ifidn <09>,<09>
jmp short keyboard_lbl
nop
db 0
keyboard_lbl label near
endif
call do_int_stacks
dw old09
int09 endp
public int70
public old70
old70 dd 0
int70 proc far
call do_int_stacks
dw old70
int70 endp
irp a,<0a,0b,0c,0d,0e,72,73,74,76,77>
public int&a
public old&a
public firstflag&a
int&a proc far
jmp short entry_int&a&_stk
old&a dd 0 ;forward pointer
dw 424bh ;compatible signature for int. sharing
firstflag&a db 0 ;the firstly hooked.
jmp short intret_&a ;reset routine. we don't care this.
db 7 dup (0) ;reserved for future.
entry_int&a&_stk:
call do_int_stacks
dw old&a
intret_&a:
jmp DOIRET
int&a endp
endm
DOCLI:
FCLI
ret
DOSTI:
FSTI
ret
DOIRET:
FIRET
;********************************************************************
;common routines
; do interrupt stack switching. the fake return address holds
; a pointer to the far-pointer of the actual interrupt
; service routine
do_int_stacks:
push ax
push bp
push es
mov es, cs:[stacks+2] ; get segment of stacks
mov bp,nextentry ; get most likely candidate
mov al,allocated
xchg es:byte ptr allocbyte[bp],al ; grab the entry
cmp al,free ; still avail?
jne notfree02
sub nextentry,entrysize ; set for next interrupt
found02:
mov es:word ptr savedsp[bp],sp ; save sp value
mov es:word ptr savedss[bp],ss ; save ss also
mov ax,bp ; temp save of table offset
mov bp,es:word ptr newsp[bp] ; get new sp value
cmp es:[bp],ax ; check for offset into table
jne foundbad02
push bp
mov bp,sp
mov ax,8[bp] ; get offset of interrupt vector
pop bp
push es ; ss:sp = new stack
pop ss
mov sp,bp
mov bp,ax ; get pointer to interrupt vector
mov bp,cs:[bp]
pushf ; go execute the real interrupt handler
call cs:dword ptr [bp] ; call the old interrupt vector
mov bp,sp ; retrieve the table offset for us
mov bp,es:[bp] ; but leave it on the stack
mov ss,es:word ptr savedss[bp] ; get old stack back
mov sp,es:word ptr savedsp[bp]
mov es:byte ptr allocbyte[bp],free ; free the entry
mov nextentry,bp ; setup to use next time
newerror02:
pop es
pop bp ; saved on entry
pop ax ; saved on entry
add sp,2 ; lose the fake return address
intret_02:
jmp DOIRET ; done with this interrupt
notfree02:
cmp al,allocated ; error flag
je findnext02 ; no, continue
xchg es:byte ptr allocbyte[bp],al ; yes, restore error value
findnext02:
call longpath
jmp found02
foundbad02:
cmp bp,firstentry
jc findnext02
mov bp,ax ; flag this entry
mov es:byte ptr allocbyte[bp],clobbered
jmp findnext02 ; keep looking
longpath:
mov bp,lastentry ; start with last entry in table
lploopp:
cmp es:byte ptr allocbyte[bp],free ; is entry free?
jne inuse ; no, try next one
mov al,allocated
xchg es:byte ptr allocbyte[bp],al ; allocate entry
cmp al,free ; is it still free?
je found ; yes, go use it
cmp al,allocated ; is it other than allocated or free?
je inuse ; no, check the next one
mov es:byte ptr allocbyte[bp],al ; yes, put back the error state
inuse:
cmp bp,firstentry
je fatal
sub bp,entrysize
jmp lploopp
found:
ret
fatal proc near
; NTVDM support for pc convertable is NOT NEEDED 10-Aug-1992 Jonle
;
; push ds
; mov ax, 0f000h ;look at the model byte
; mov ds, ax
; cmp ds:byte ptr [0fffeh], mdl_convert ;convertible?
; pop ds
; jne skip_nmis
;
; mov al,07h ; disable pc convertible nmis
; out 72h,al
;
;skip_nmis:
call DOCLI ; disable and mask
mov al,0ffh ; all other ints
out 021h,al
out 0a1h,al
mov si,cs
mov ds,si
mov si,offset fatal_msg
;SR;
; We set all foci to this VM to issue the stack failure message
;
push ax
push ds
mov ax,Bios_Data
mov ds,ax
assume ds:Bios_Data
test ds:[IsWin386],1
pop ds
pop ax
assume ds:nothing
jz fatal_loop ;win386 not present, continue
call V86_Crit_SetFocus ;set focus to this VM
;
;SR; We do not bother about the returned status of this call.
;
fatal_loop:
lodsb
cmp al,'$'
je fatal_done
mov bl,7
mov ah,14
int 010h ; whoops, this enables ints
jmp fatal_loop
fatal_done:
jmp fatal_done
fatal endp
include msbio.cl5 ;fatal stack error message
.xall
public endstackcode
endstackcode label byte
endif
sysinit:
jmp goinit
;
;----------------------------------------------------------------------------
;
DDHighInfo struc
ddhigh_CSegPtr dd ? ; pointer to code segment to be relocated
ddhigh_CSegLen dw ? ; length of code segment to be relocated
ddhigh_CallBak dd ? ; pointer to the call back routine
DDHighInfo ends
public runhigh
runhigh db 0h
dosinfo dd 0 ; address of the DOS Sysini Variables
dos_temp_location label dword
dosinit dw 0
current_dos_location dw 0
device_list dd 0
sysi_country dd 0 ; pointer to country table in dos
dos_segreinit dw 0,0 ; room for dword
lo_doscod_size dw 0 ; dos code size when in low mem
hi_doscod_size dw 0 ; dos code size when in HMA
def_php dw 0
; M022--
; pointer for calling into Bios_Code for re-initializing segment values.
; call with ax = new segment for Bios_Code. Notice that we'll
; call it in its temporary home, cuz seg_reinit won't get moved to
; the new home.
seg_reinit_ptr label dword
dw offset Bios_Code:seg_reinit
temp_bcode_seg dw Bios_Code
;variables for stack initialization program.
if stacksw
stack_count dw defaultcount
stack_size dw defaultsize
stack_addr dd 0
endif
; various default values
memory_size dw 1
RPLMemTop dw 0
default_drive db 0 ;initialized by ibminit.
buffers dw -1 ; initialized during buffer allocation
h_buffers dw 0 ; # of the heuristic buffers. initially 0.
singlebuffersize dw ? ; maximum sector size + buffer header
files db 8 ; enough files for pipe
fcbs db 4 ; performance for recycling
keep db 0 ; keep original set
num_cds db 1 ; minimum needed is 1, so that initialization does'nt have a problem
confbot dw ?
alloclim dw ?
DirStrng db "A:\",0 ; string for the root directory of a drive
command_line db 2,0,"P" ;default command.com args
db 125 dup (0)
zero db 0
sepchr db 0
linecount dw 0 ; line count in config.sys
showcount db ' ',cr,lf,'$' ; used to convert linecount to ascii.
buffer_linenum dw 0 ; line count for "buffers=" command if entered.
buf_prev_off dw 0
if not noexec
comexe exec0 <0,command_line,default_drive,zero>
endif
;------------------------------------------------------------------
; variables for install= command.
multi_pass_id db 0 ; parameter passed to multi_pass
; indicating the pass number
; 0 - do scan for DOS=HIGH/LOW
; 1 - load device drivers
; 2 - was to load IFS
; now it is unused
; 3 - do install=
; >3 - nop
install_flag dw 0
have_install_cmd equ 00000001b ; config.sys has install= commands
has_installed equ 00000010b ; sysinit_base installed.
config_size dw 0 ; size of config.sys file. set by sysconf.asm
sysinit_base_ptr dd 0 ; pointer to sysinit_base
sysinit_ptr dd 0 ; returning addr. from sysinit_base
checksum dw 0 ; used by sum_up
ldexec_fcb db 20 dup (' ') ;big enough
ldexec_line db 0 ;# of parm characters
ldexec_start db ' '
ldexec_parm db 80 dup (0)
instexe exec0 <0,ldexec_line,ldexec_fcb,ldexec_fcb>
;------------------------------------------------------------------
;variables for comment=
com_level db 0 ;level of " " in command line
cmmt db 0 ;length of comment string token
cmmt1 db 0 ;token
cmmt2 db 0 ;token
cmd_indicator db ?
donotshownum db 0
;------------------------------------------------------------------
count dw 0
org_count dw 0
chrptr dw 0
cntryfilehandle dw 0
old_area dw 0
impossible_owner_size dw 0 ; paragraph
;------------------------------------------------------------------
bucketptr label dword
bufptr label dword ;leave this stuff in order!
memlo dw 0
prmblk label word
memhi dw 0
ldoff dw 0
area dw 0
packet db 24 ; was 22
db 0
db 0 ;initialize code
dw 0
db 8 dup (?)
unitcount db 0
break_addr dd 0
bpb_addr dd 0
drivenumber db 0
configmsgflag dw 0 ; used to control "error in config.sys line #" message
toomanydrivesflag db 0 ;>24 fixed disk partitions flag ; M029
BCodeSeg dw Bios_Code
;SR;
; This is the communication block between the DOS and the BIOS. It starts at
;the SysinitPresent flag. Any other data that needs to be communicated
;to the DOS should be added after SysinitPresent. The pointer to this block
;is passed to DOS as part of the DOSINIT call.
;
BiosComBlock dd Bios_Data:SysinitPresent
tempstack db 80h dup (?)
goinit:
ifdef JAPAN
mov ah,50h ; set crt mode
mov al,0
mov bx,81 ; for JAPAN
int 10h
mov ah,50h ; set keyboard mode
mov al,0
mov bx,81 ; for JAPAN
int 16h
endif
cld
;; Before we installed spckbd.asm (we hook a lot of vectors there),
;; we shouldn't invoke any interrupt calls directly to bios(they will
;; go directly to ROM bios). Since we do know what exactly those ROM
;; bios(s) do, a safer manner is to issue bop to our 32 bits side.
;; int 12h ; Get Memory in 1k
BOP 12h
mov cl,6
shl ax,cl ;convert to 16-byte blocks(segment no.)
mov cx,ax
dec cx ; one para for an arena at end of mem
; in case of UMBs
mov memory_size,cx
push cs
pop ds
xor si,si
mov di,si
mov ax, offset sysinitgrp:SI_end ; need this much room for sysinit
call off_to_para
sub cx,ax
; we need to leave room for the DOS and for the BIOS
; code above sysinit in memory
;
sub cx,dossize/16 ; leave this much room for DOS
mov ax,offset BCode_end
call off_to_para ; leave this much room for BIOS code
sub cx,ax
mov es,cx ; offset where sysinit will be located
mov cx,offset sysinitgrp:SI_end
shr cx,1 ;divide by 2 to get words
rep movsw ;relocate sysinit
push es ; push relocated segment
mov ax,offset sysin
push ax ; push relocated entry point
retf ; far jump to relocated sysinit
; move the dos to its proper location
sysin:
assume ds:nothing,es:nothing,ss:nothing
mov ax, Bios_Data ; point DS to BIOS data
mov ds, ax
assume ds:Bios_Data
mov word ptr MoveDOSIntoHMA+2, cs ; set seg of routine to move DOS
mov SysinitPresent, 1 ; flag that MoveDOSIntoHMA can be called
SVC SVC_ISDEBUG
mov DemInfoFlag, al
test al,ISDBG_DEBUGGEE
je @f
SAVEREG <bx,dx,es>
mov bx, cs ; current base of BIOS
xor cx, cx
mov dx, current_dos_location; get offset of end of code
sub dx, bios_data ; add in length of data segment
REPT 4
shl dx, 1
rcl cx, 1
endm
mov ax, SYMOP_LOAD SHL 8 + ID_NTIO
SVC SVC_DEMSYSTEMSYMBOLOP
mov bx, 1 ; bugbug: Hardcoded segment number
mov ax, ds ; low segment location
mov es, ax ; relocated segment
mov ax, SYMOP_MOVE SHL 8 + ID_NTIO
SVC SVC_DEMSYSTEMSYMBOLOP
RESTOREREG <es,dx,bx>
@@:
; first move the MSDOS.SYS image up to a harmless place
; on top of our new sysinitseg
mov ax,offset sysinitgrp:SI_end ; how big is sysinitseg?
call off_to_para
mov cx,cs ; pick a buffer for msdos above us
add ax,cx
mov es,ax
xor si,si
mov di,si
mov ds,[current_dos_location] ; where it is (set by msinit)
assume ds:nothing
mov cx,dossize/2
rep movsw
mov [current_dos_location],es
; The DOS code is ORGed at a non-zero value to allow it to be located in
; HIMEM. Thus, the DOS segment location must be adjusted accordingly.
mov ax,ds:word ptr 3 ; get offset of dos
mov [dosinit],ax ; that's the entry point offset
call off_to_para ; subtract this much from segment
sub [current_dos_location],ax
; BIOS code is moved to the top of memory
; until it is determined whether it will be running in HIMEM or not.
; now put Bios_Code up on top of that. Assume Bios_Code + dossize < 64k
mov ax,es
add ax,dossize/16 ; get paragraph of end of dos
mov es,ax
xchg ax,temp_bcode_seg ; swap with original home of Bios_Code
mov ds,ax ; point to loaded image of Bios_Code
assume ds:nothing
mov si,offset BCode_start
mov di,si
mov cx,offset BCode_end
sub cx,si
shr cx,1
rep movsw ; move Bios_Code into place
mov ax,es ; tell it what segment it's in
call [seg_reinit_ptr] ; far call to seg_reinit in Bios_Code (M022)
; now call dosinit while it's in its temporary home
les di,cs:[BiosComBlock] ; ptr to BIOS communication block
lds si,cs:[device_list] ; set for call to dosinit
assume ds:nothing, es:nothing
mov dx,cs:[memory_size] ; set for call to dosinit
call DOCLI
mov ax,cs
mov ss,ax
align 2 ; assembler wouldn't let me do an "and 0fffeh"
locstack label byte ; on the mov sp,offset locstack
mov sp,offset locstack ; set stack
call DOSTI
; This call to DOSINIT will relocate the DOS data from its present location
; at the top of memory, to its final location in low memory just above the
; BIOS data. It will then build important DOS data structures in low
; memory following the DOS data. It returns (among many other things) the
; new starting address of free memory.
call [dos_temp_location] ; call dosinit
;es:di -> sysinitvars_ext
mov [def_php],ds ; save pointer to PSP
mov [hi_doscod_size],ax ; size of doscode (including exepatch)
mov [lo_doscod_size],cx ; (not including exepatch)
mov [dos_segreinit],dx ; save offset of segreinit
mov ax,word ptr es:[di.sysi_initvars]
mov word ptr dosinfo,ax
mov ax,word ptr es:[di.sysi_initvars+2]
mov word ptr [dosinfo+2],ax ;set the sysvar pointer
mov ax,word ptr es:[di.sysi_country_tab]
mov word ptr [sysi_country],ax
mov ax,word ptr es:[di.sysi_country_tab+2]
mov word ptr [sysi_country+2],ax ;set the sysi_country pointer
mov es,[current_dos_location] ; give dos its temporary loc.
mov [dos_segreinit+2],es
;
les di,dosinfo ;es:di -> dosinfo
clc ;get the extended memory size
; execute the get extended memory size subfunction in the bios int 15h
; if the function reports an error do nothing else store the extended
; memory size reported at the appropriate location in the dosinfo buffer
; currently pointed to by es:di. use the offsets specified in the
; definition of the sysinitvars struct in inc\sysvar.inc
mov ah,88h
;; IBM ps/2 90 int 15(ah = 88h) read a coms byte(0B6h) which we don't support.
;; it returns 0 on this query.
;; we issue a bop to 32bits to get the real extended memeory size
;; int 15h ;check extended memory size
BOP 15h
;; jc no_ext_memory
mov es:[di].sysi_ext_mem,ax ;save extended memory size
;; or ax, ax
no_ext_memory:
mov ax,es:[di.sysi_maxsec] ; get the sector size
add ax,bufinsiz ; size of buffer header
mov [singlebuffersize],ax ; total size for a buffer
SVC SVC_DEMGETBOOTDRIVE
mov [default_drive],al
mov es:[di.sysi_boot_drive],al ; set sysi_boot_drive
; determine if 386 system...
if 1
get_cpu_type ; macro to determine cpu type
cmp ax,2 ; is it a 386?
jne not_386_system ; no: don't mess with flag
endif
mov es:[di.sysi_dwmove],1
not_386_system:
mov al,es:[di.sysi_numio]
mov drivenumber,al ; save start of installable block drvs
mov ax,cs
sub ax,11h ; room for PSP we will copy shortly
mov cx,[singlebuffersize] ; temporary single buffer area
shr cx,1
shr cx,1 ; divide size by 16...
shr cx,1
shr cx,1 ; ...to get paragraphs...
inc cx ; ... and round up
; cas note: this unorthodox paragraph rounding scheme wastes a byte if
; [singlebuffersize] ever happens to be zero mod 16. Could this
; ever happen? Only if the buffer overhead was zero mod 16, since
; it is probably safe to assume that the sector size always will be.
;
; mohans also found a bug in CONFIG.SYS processing where it replaces
; EOF's with cr,lf's, without checking for collision with [confbot].
; perhaps the extra byte this code guarantees is what has kept that
; other code from ever causing a problem???
sub ax,cx
mov [confbot],ax ; temp "unsafe" location
; push es ; preserve pointer to DOSINFO data
; push di
; setup and initialize the temporary buffer
; les di,es:[di.sysi_buf] ;get the buffer chain entry pointer
; mov word ptr es:[di.Dirty_Buff_Count],0
; mov word ptr es:[di.Buff_Queue],0
; mov word ptr es:[di.Buff_Queue+2],ax
; mov es,ax
; xor ax,ax
; mov di,ax ;es:di -> single buffer
; mov es:[di.buf_next],ax ;points to itself
; mov es:[di.buf_prev],ax ;points to itself
; mov word ptr es:[di.buf_id],00ffh ;free buffer,clear flag
; mov word ptr es:[di.buf_sector],0
; mov word ptr es:[di.buf_sector+2],0
; pop di ; restore pointer to DOSINFO data
; pop es
push cs
pop ds
assume ds:sysinitseg
call tempcds ; set up cdss so re_init and sysinit
; can make disk system calls
assume ds:nothing ; tempcds trashes ds
mov ds,[def_php] ; retreive pointer to PSP returned by DOSINIT
if not ibmjapver
call re_init ; re-call the bios
endif
call DOSTI ; ints ok
cld ; make sure
; dosinit has set up a default "process" (php) at ds:0. we will move it out
; of the way by putting it just below sysinit at end of memory.
mov bx,cs
sub bx,10h
mov es,bx
xor si,si
mov di,si
mov cx,80h
rep movsw
mov word ptr es:[pdb_jfn_pointer + 2],es ; relocate
mov ah,set_current_pdb
int 21h ; tell dos we moved it
push ds ; preserve DS returned by DOSINIT
push cs
pop ds ; point DS to sysinitseg
assume ds:sysinitseg
; set up temp. critical error handler
mov dx,offset int24 ;set up int 24 handler
mov ax,(set_interrupt_vector shl 8) or 24h
int 21h
cmp byte ptr [TooManyDrivesFlag],0 ;Q: >24 partitions? M029
je no_err ; N: continue M029
mov dx,offset TooManyDrivesMsg ; Y: print error message M029
call print ; M029
no_err: ; M029
pop ds ; start of free memory
assume ds:nothing
mov dl,[default_drive]
or dl,dl
jz nodrvset ; bios didn't say
dec dl ; a = 0
mov ah,set_default_drive
int 21h ;select the disk
nodrvset:
;
; Process the CONFIG.SYS file
;
ProcessConfig:
;
; NTVDM store temp file name for config.sys, 23-Nov-1992 Jonle
;
push ds
push cs
pop ds
assume ds:sysinitseg
mov dx,offset config ; ds:dx points file description
CMDSVC SVC_GETCONFIGSYS
pop ds
assume ds:nothing
ifndef TAIWAN
call doconf ;do pre-scan for dos=high/low
else ; taiwan
call chkoemlocaldrv
mov cs:oemdriverinst,ax
call cdosinit
push es
push bx
pop bx
pop es
call maketempvector ;make dummy int service routine
call doconf ;do pre-scan for dos=high/low
call chklocalexist ;check if local dev drv exist
;if not found,system halt
call recovercsiint ;recover csi interrupt vector
endif ; taiwan
; Now, we decide what to do with the DOS code.
; It will either be relocated to low memory, above the DOS data structures,
; or else it will be located in HiMem, in which case a stub with the DOS
; code entry points will be located in low memory. Dos_segreinit is used
; to tell the DOS data where the code has been placed, and to install the
; low memory stub if necessary. If the DOS is going to go into HiMem, we
; must first initialize it in its present location and load the installable
; device drivers. Then, if a HiMem driver has been located, we can actually
; relocate the DOS code into HiMem.
;
; M025 begin
cmp runhigh, 0 ; Did user choose to run low ?
je dont_install_stub ; yes, don't install dos low mem stub
;
;------ user chose to load high
;
mov es,[current_dos_location] ; give dos its temporary loc.
xor ax,ax ; ax = 00 ---> install stub
call cs:dword ptr [dos_segreinit] ; call dos segreinit
jmp short do_multi_pass
;
;------ User chose to load dos low
;
dont_install_stub:
xor bx, bx ; M012
; don't use int 21 call to alloc mem
call MovDOSLo ; move it !
mov ax, 1 ; dont install stub
mov es, current_dos_location; set_dos_final_position set it up
call dword ptr dos_segreinit ; inform dos about new seg
do_multi_pass:
call AllocFreeMem ; allocate all the free mem
; & update [memhi] & [area]
; start of free memory.
; M025 end
; NTVDM
; Copy softpc keyboard driver resident code to start of free mem
; Install Softpc IVT hooks
mov al,devmark_spc
call setdevmark
mov es, cs:[devmark_addr]
mov word ptr es:[arena_name], 'BK'
mov word ptr es:[arena_name+2], 'D'
cld
mov ax,[memhi]
push ds
mov cx,Bios_Data
mov ds,cx
assume ds:Bios_Data
mov word ptr spc_mse_int10,offset int10h_vector
mov word ptr spc_mse_int10+2,ax
mov word ptr int29Perf,offset outchr ; sudeepb 03-Nov-1992
mov word ptr int29Perf+2,ds ; added for int10 performance
pop ds
assume ds:nothing
mov es,ax ;es dest seg. for SpcKbd
push es
push cs
pop ds ;ds src seg for SpcKbd
mov si,offset sysinitgrp:SpcKbdBeg
mov cx,offset sysinitgrp:SpcKbdEnd
sub cx,si
xor di,di
mov [memlo],cx
or [setdevmarkflag],for_devmark
call round
rep movsb
pop ds
call sysinitgrp:InstSpcKbd
; save value of int09 for int 09 hardware stack disable
xor ax,ax
mov ds,ax
mov si, 09h*4
lodsw
mov word ptr cs:old09, ax
lodsw
mov word ptr cs:old09+2, ax
; save value of int08 for int 08 hardware stack disable
mov si, 08h*4
lodsw
mov word ptr cs:old08, ax
lodsw
mov word ptr cs:old08+2, ax
; NTVDM
; Attempt to init emm memory manager. if we have emm
; then load internal emm stub device driver.
;
; check if emm memory is available
mov ax, [memhi]
inc ax ;1 para for arena header
mov ds, ax ;expected seg for emm drv
call sysinitgrp:InitSpcEmm
cmp ax, 0
jne NoEmmServices
; fill in the arena name
mov al, devmark_device
call setdevmark
mov es, cs:[devmark_addr]
mov word ptr es:[arena_name], 'ME'
mov word ptr es:[arena_name+2], 'M'
; copy in emm stub driver code
cld
mov ax,[memhi]
mov es,ax
push es ;save for diddling devheader
push cs
pop ds
mov si,offset sysinitgrp:SpcEmmBeg
mov cx,offset sysinitgrp:SpcEmmEnd
sub cx,si
xor di,di
mov [memlo],cx
or [setdevmarkflag],for_devmark
call round
rep movsb
; link in emm stub driver
; so apps can find emm driver
pop ds
xor si, si ;ds:si = device header
les di, cs:[dosinfo] ;es:di = to dos info
mov cx,word ptr es:[di.sysi_dev] ;dx:cx = head of list
mov dx,word ptr es:[di.sysi_dev+2]
mov word ptr es:[di.sysi_dev],si ;set head of list in dos
mov word ptr es:[di.sysi_dev+2],ds
mov word ptr ds:[si], cx ;link in the driver
mov word ptr ds:[si+2], dx
NoEmmServices:
; Now, process config.sys some more.
; Load the device drivers and install programs
inc cs:multi_pass_id ; multi_pass_id = 1
call multi_pass ; load device drivers
; NTVDM
; Install Softpc Mouse driver in UMB if can else in LOW memory
; This must be done after himem.sys is loaded for umb support
;
mov cx, offset sysinitgrp:SpcMseEnd
sub cx, offset sysinitgrp:SpcMseBeg ; cx, size of SpceMse
mov di, offset MseDev
push cs
pop es ; es:di, dest
push cx ; preserve cx
call AllocUMBLow
pop cx
push es ; save to pass to InstSpcMse
mov si, offset sysinitgrp:SpcMseBeg
push cs
pop ds ; ds:si, Source of SpcMse code
rep movsb
pop ds
call sysinitgrp:InstSpcMse
call ShrinkUMB
call UnlinkUMB ; unlink all UMBs ;M002
inc cs:multi_pass_id ; multi_pass_id = 2
call multi_pass ; was load ifs (now does nothing)
call endfile ; setup fcbs, files, buffers etc
;
;Reset SysinitPresent flag here. This is needed for the special fix for lying
;to device drivers. This has been moved up to this point to avoid problems
;with overlays called from installed programs
;
mov ax,Bios_Data
mov es,ax ; point ES to bios data
assume es:Bios_Data
mov es:SysinitPresent,0 ; clear SysinitPresent flag
test install_flag,have_install_cmd ; are there install commands?
jz dolast ; no, no need for further processing
inc cs:multi_pass_id ; mult_pass_id = 3
call multi_pass ; execute install= commands
dolast:
assume es:nothing
; [area] has the segment address for the allocated memory of sysinit, confbot.
; free the confbot area used for config.sys and sysinit itself.
; Now if DOS is supposed to run high, we actually move it into high memory
; (if HiMem manager is available).
;
; There is also this little hack for CPM style DOS calls that needs to
; be done when A20 is set...
cmp runhigh, 0ffh ; are we still waiting to be moved?
jne @f ; no, our job is over
call LoadDOSHiOrLo
@@:
cmp runhigh, 0 ; are we running low
je @f ; yes, no CPM hack needed
call CPMHack ; make ffff:d0 same as 0:c0
@@:
; We are now done with CONFIG.SYS processing
ConfigDone:
;; let NTVDM knows that we have done config.sys processing
xor al, al ;config.sys done
BOP BOP_NOTIFICATION ;
call AllocUMB ; allocate remaining UMBs if there are any
mov cs:[donotshownum],1 ; done with config.sys. do not show line number message.
mov es,[area]
assume es:nothing
mov ah,49h ; free allocated memory for command.com
int 21h
test cs:[install_flag],has_installed ; sysinit_base installed?
jz skip_free_sysinitbase ; no.
;set block from the old_area with impossible_owner_size.
;this will free the unnecessary sysinit_base that had been put in memory to
;handle install= command.
push es
push bx
mov es,cs:[old_area]
mov bx,cs:[impossible_owner_size]
mov ah,setblock
int 21h
mov ax,es
dec ax
mov es,ax ;point to arena
mov es:[arena_owner],8 ;set impossible owner
mov word ptr es:[arena_name], 'DS' ; System Data
pop bx
pop es
skip_free_sysinitbase:
if noexec
mov bp,ds ;save command.com segment
push ds
pop es
mov bx,cs
sub bx,10h ; point to current php
mov ds,bx
xor si,si
mov di,si
mov cx,80h
rep movsw ; copy it to new location for shell
mov word ptr es:[pdb_jfn_pointer + 2],es ; relocate
mov bx,es
mov ah,set_current_pdb
int 21h ; tell dos we moved it
mov es:[pdb_parent_pid],es ;we are the root
endif ; noexec
push cs
pop ds ; point DS to sysinitseg
assume ds:sysinitseg
; set up the parameters for command
mov si,offset command_line+1
if noexec
mov di,81h
else
push ds
pop es
mov di,si
endif
mov cl,-1
comtranlp: ;find length of command line
inc cl
lodsb
stosb ;copy command line in
or al,al
jnz comtranlp
dec di
mov al,cr ; cr terminate
stosb
if noexec
mov es:[80h],cl ; set up header
mov al,[default_drive]
mov es:[5ch],al
else
mov [command_line],cl ;count
endif
mov dx,offset commnd ;now pointing to file description
if noexec
mov es,bp ;set load address
mov bx,100h
call dfil ;read in command
jc comerr
mov ds,bp
mov dx,80h
mov ah,set_dma ;set disk tranfer address
int 21h
call DOCLI
mov ss,bp
mov sp,dx
call DOSTI
xor ax,ax ;push a word of zeros
push ax
push bp ;set high part of jump address
mov ax,100h
push ax ;set low part of jump address
retf ;crank up command!
else ; not noexec
; we are going to open the command interpreter and size it as is done in
; ldfil. the reason we must do this is that sysinit is in free memory. if
; there is not enough room for the command interpreter,exec will probably
; overlay our stack and code so when it returns with an error sysinit won't be
; here to catch it. this code is not perfect (for instance .exe command
; interpreters are possible) because it does its sizing based on the
; assumption that the file being loaded is a .com file. it is close enough to
; correctness to be usable.
push dx ; save pointer to name
; first, find out where the command interpreter is going to go.
mov bx,0ffffh
mov ah,alloc
int 21h ;get biggest piece
mov ah,alloc
int 21h ; second time gets it
jc memerrjx ; oooops
mov es,ax
mov ah,dealloc
int 21h ; give it right back
mov bp,bx
; es:0 points to block,and bp is the size of the block
; in para.
; we will now adjust the size in bp down by the size of sysinit. we
; need to do this because exec might get upset if some of the exec
; data in sysinit is overlayed during the exec.
mov bx,[memory_size] ; get location of end of memory
mov ax,cs ; get location of beginning of sysinit
sub bx,ax ; bx is size of sysinit in para
add bx,11h ; add the sysinit php
sub bp,bx ; sub sysinit size from amount of free memory
jc memerrjx ; if there isn't even this much memory, give up
mov ax,(open shl 8) ;open the file being execed
stc ;in case of int 24
int 21h
jc comerr ; ooops
mov bx,ax ;handle in bx
xor cx,cx
xor dx,dx
mov ax,(lseek shl 8) or 2
stc ;in case of int 24
int 21h ; get file size in dx:ax
jc comerr
; convert size in dx:ax to para in ax
add ax,15 ; round up size for conversion to para
adc dx,0
call off_to_para
mov cl,12
shl dx,cl ; low nibble of dx to high nibble
or ax,dx ; ax is now # of para for file
add ax,10h ; 100h byte php
cmp ax,bp ; will command fit in available mem?
jb okld ; jump if yes.
memerrjx:
jmp mem_err
okld:
mov ah,close
int 21h ; close file
pop dx ; recover pointer to name
push cs ; point es to sysinitseg
pop es
mov bx,offset comexe ; point to exec block
mov word ptr [bx.exec0_com_line+2],cs ; set segments
mov word ptr [bx.exec0_5c_fcb+2],cs
mov word ptr [bx.exec0_6c_fcb+2],cs
xor ax,ax ;load and go
mov ah,exec
stc ;in case of int 24
int 21h ;go start up command
endif
; note fall through if exec returns (an error)
comerr:
mov dx,offset badcom ;want to print command error
extrn badfil:near
call badfil
public stall
stall: SVC SVC_DEMEXITVDM ; Will Kill The VDM
;
;----------------------------------------------------------------------------
; procedure : AllocFreeMem
;
; Allocate Max memory from DOS to find out where to load DOS.
; DOS is at temporary location when this call is being made
;
; Inputs : None
; Outputs: The biggest chunk of memory is allocated (all mem at init time)
; [area] & [memhi] set to the para value of the start of the
; free memory.
;
; Uses : AX, BX
;
;----------------------------------------------------------------------------
;
AllocFreeMem proc near
assume es:nothing, ds:nothing
mov bx,0ffffh
mov ah,alloc
int 21h ;first time fails
mov ah,alloc
int 21h ;second time gets it
mov [area],ax
mov [memhi],ax ; memhi:memlo now points to
ret
; start of free memory
AllocFreeMem endp
; start M000
include msbio.cl6
; end M000
;
;----------------------------------------------------------------------------
;
; procedure : LoadDOSHiOrLo
;
; Tries to move DOS into HMA. If it fails then loads
; DOS into Low memory.
;
;----------------------------------------------------------------------------
;
LoadDOSHiOrLo proc near
call TryToMovDOSHi ; Try moving it into HMA (M024)
jc LdngLo ; If that don't work...
ret
LdngLo:
push cs
pop ds
mov ah, 9
mov dx, offset DOSLOMSG ; inform user that we are
int 21h ; loading low
; actually move the dos, and reinitialize it.
mov bx, 1 ; M012
; use int 21 alloc for mem
call MovDOSLo
mov es,[current_dos_location] ; give dos its temporary loc.
xor ax,ax ; ax = 00 ---> install stub
call cs:dword ptr [dos_segreinit] ; call dos segreinit
mov runhigh, 0 ; mark that we are running lo
ret
LoadDOSHiOrLo endp
;
;----------------------------------------------------------------------------
;
; procedure : TryToMovDOSHi
;
; This tries to move DOS into HMA.
; Returns CY if it failed.
; If it succeeds returns with carry cleared.
;
;
;----------------------------------------------------------------------------
;
public TryToMovDOSHi
TryToMovDOSHi proc near
call MovDOSHi
jc ttldhx
mov es,[current_dos_location] ; give dos its temporary loc.
xor ax,ax ; ax = 00 ---> install stub
call cs:dword ptr [dos_segreinit] ; call dos segreinit
mov runhigh, 1
clc
ttldhx:
ret
TryToMovDOSHi endp
;
;----------------------------------------------------------------------------
;
; procedure : MovDOSHi
;
; Tries to allocate HMA and Move DOS/BIOS code into HMA
;
; Returns : CY if it failed
;
;----------------------------------------------------------------------------
;
MovDOSHi proc near
call AllocHMA
jc mdhx ; did we get HMA?
mov ax, 0ffffh ; yes, HMA seg = 0ffffh
mov es, ax
; actually move the BIOS and DOS
call MovBIOS ; First move BIOS into HMA
; ES:DI points to free HMA after BIOS
mov cx, hi_doscod_size ; pass the code size of DOS
; when it is in HMA
call MovDOS ; and move it
; ES:DI points to free HMA after DOS
call SaveFreeHMAPtr ; Save the Free HMA ptr
clc
mdhx:
ret
MovDOSHi endp
;
;----------------------------------------------------------------------------
;
; procedure : MovDOSLo
;
; Allocates memory from DOS and moves BIOS/DOS code into it
;
;----------------------------------------------------------------------------
;
MovDOSLo proc near
call AllocMemForDOS ;
mov es, ax ; pass the segment to MovBIOS
call MovBIOS
;
;------ ES:DI points memory immediately after BIOS
;
mov cx, lo_doscod_size ; DOS code size when loaded
; low
call MovDOS
ret
MovDOSLo endp
;
;----------------------------------------------------------------------------
;
; procedure : MovBIOS
;
; Moves BIOS code into requested segment
;
; In : ES - segment to which BIOS is to be moved
; ( it moves always into offset BCode_Start)
;
; Out : ES:DI - pointer to memory immediately after BIOS
;
;----------------------------------------------------------------------------
;
MovBIOS proc near
mov ds, temp_bcode_seg ; current BIOS code seg
mov si, offset BCode_Start
mov di, si
mov cx, offset BCode_End
sub cx, si ; size of BIOS
shr cx, 1 ; Both the labels are para
; aligned
rep movsw
push es
push di ; save end of BIOS
mov ax, es
mov BCodeSeg, ax ; save it for later use
call [seg_reinit_ptr] ; far call to seg_reinit (M022)
pop di
pop es ; get back end of BIOS
ret
MovBIOS endp
;
;----------------------------------------------------------------------------
;
; procedure : MovDOS
;
; Moves DOS code into requested area
;
; In : ES:DI - pointer to memory where DOS is to be moved
; CX - size of DOS code to be moved
;
; Out : ES:DI - pointer to memory immediately after DOS
;
;----------------------------------------------------------------------------
;
MovDOS proc near
push es
push di
lds si, dos_temp_location ; current location of DOS
rep movsb
pop bx ; get back offset into which
; DOS was moved
mov ax, dosinit ; get the offset at which DOS
; wants to run
sub ax, bx
call off_to_para
pop bx ; get the segment at which
; we moved DOS into
sub bx, ax ; Adjust segment
mov current_dos_location, bx ; and save it
ret
MovDOS endp
;
;----------------------------------------------------------------------------
;
; procedure : AllocMemForDOS
;
; Allocate memory for DOS/BIOS code from DOS !!!
;
; Out : AX - seg of allocated memoryblock
;
;----------------------------------------------------------------------------
;
AllocMemForDOS proc near
mov ax, offset BCode_end
sub ax, offset BCode_start ; BIOS code size
add ax, lo_doscod_size ; + DOS code size
add ax, 15
call off_to_para ; convert to para
or bx, bx ; M012
; can we use int 21 for alloc
mov bx, ax
jz update_arena ; M012
mov ah, 48h ; request DOS
int 21h
jc FatalErr ; IF ERR WE ARE HOSED
sub ax, 3 ; Take care ORG 30h of
; BIOS code
mov es, ax
mov word ptr es:[20h+arena_owner], 08h ; mark it as system
mov word ptr es:[20h+arena_name], 'CS' ; code area
ret
;
; M012 : BEGIN
;
update_arena:
push ds
push di
push cx
push dx
lds di, dosinfo ; get ptr to DOS var
dec di
dec di ; Arena head is immediately
; before sysvar
mov es, ds:[di] ; es = arena head
mov cx, es:[arena_size] ; cx = total low mem size
cmp cx, bx ; is it sufficient ?
jb FatalErr ; no, fatal error
mov dl, es:[arena_signature]
mov ax, es
add ax, bx ; ax = new arena head
mov ds:[di], ax ; store it in DOS data area
mov ds, ax
mov byte ptr ds:[arena_signature], dl ; type of arena
mov word ptr ds:[arena_owner], 0 ; free
sub cx, bx ; size of the new block
mov word ptr ds:[arena_size], cx ; store it in the arena
mov ax, es ; return seg to the caller
sub ax, 3 ; Take care ORG 30h of
; BIOS code
pop dx
pop cx
pop di
pop ds
ret
;
; M012 : END
;
FatalErr:
push cs
pop ds
mov dx, offset FEMsg
mov ah, 9h
int 21h
cli
hlt
AllocMemForDOS endp
;
;----------------------------------------------------------------------------
;
; procedure : AllocHMA
;
; grab_the_hma tries to enable a20 and make sure there is memory
; up there. If it gets any sort of error, it will return with
; carry set so that we can resort to running low.
;
; It also returns ES: -> 0ffffh if it returns success
;
;----------------------------------------------------------------------------
;
AllocHMA proc near
assume ds:nothing,es:nothing
;
; cas note: The pre-286 check is no longer needed here since the
; presence of XMS is sufficient. However, this code hasn't
; been deleted because it can be recycled for skipping the
; extra pass of CONFIG.SYS and assuming we're running low
; in the case of a pre-286.
;
;; see if we're running on a pre-286. If not, force low.
;
; xor ax,ax
; pushf ; save flags (like int)
; push ax
; popf
; pushf
; pop ax
; popf ; restore original flags (like int)
; and ax,0f000h
; cmp ax,0f000h ; 8088/8086?
; jz grab_hma_error
;
push ds
mov ax,Bios_Data
mov ds,ax
assume ds:Bios_Data
call IsXMSLoaded
jnz grabhma_error
mov ax,4310h
int 2fh ; get the vector into es:bx
mov word ptr xms,bx
mov word ptr xms+2,es
mov ah,1 ; request HMA
mov dx,0ffffh
call xms
dec ax
jz @f ; error if not able to allocate HMA
;
;------ Himem may be lying because it has allocated mem for int 15
;
mov ah, 88h
int 15h
cmp ax, 64 ; less than 64 K of hma ?
jb grabhma_error
@@: mov ah,5 ; localenableA20
call xms
dec ax
jnz grabhma_error ; error if couldn't enable A20
mov ax,0ffffh
mov es,ax
mov es:word ptr 10h,1234h ; see if we can really read/write there
cmp es:word ptr 10h,1234h
jnz grabhma_error ; don't try to load there if XMS lied
clc
pop ds
ret
grabhma_error:
stc
pop ds
assume ds:nothing
ret
AllocHMA endp
;
;----------------------------------------------------------------------------
;
; procedure : IsXMSLoaded
;
; Checks whether a XMS driver is loaded
;
; Returns : Z flag set if XMS driver loaded
; Z flag reset if no XMS drivers are present
;
;----------------------------------------------------------------------------
;
public IsXMSLoaded
IsXMSLoaded proc near
mov ax,4300h
int 2fh
cmp al,80h ; XMS installed?
ret
IsXMSLoaded endp
;
;
;----------------------------------------------------------------------------
; procedure : FTryToMovDOSHi
;
; Called from HMA suballoc calls
;
;----------------------------------------------------------------------------
;
;
public FTryToMovDOSHi
FTryToMovDOSHi proc far
push ax
push bx
push cx
push dx
push si
push di
push ds
push es
cmp runhigh, 0ffh
jne @f
call TryToMovDOSHi
@@:
pop es
pop ds
pop di
pop si
pop dx
pop cx
pop bx
pop ax
ret
FTryToMovDOSHi endp
;
;----------------------------------------------------------------------------
;
; procedure : SaveFreeHMAPtr
;
; Save the Free HMA pointer in BIOS variable for later use.
; (INT 2f ax==4a01 call returns pointer to free HMA)
; Normalizes the pointer to ffff:xxxx format and stores only
; the offset.
;
; Inputs : ES:DI - pointer to free HMA
; Output : FreeHMAPtr in BIOS data segment updated
;
;----------------------------------------------------------------------------
;
SaveFreeHMAPtr proc near
mov bx, es
mov ax, 0ffffh ; HMA segment
sub ax, bx
add di, 15 ; para round
and di, 0fff0h
mov cl, 4
shl ax, cl
sub di, ax
push ds
mov ax, Bios_Data
mov ds, ax
assume ds:Bios_Data
mov FreeHMAPtr, di
mov inHMA, 0ffh
pop ds
assume ds:nothing
ret
SaveFreeHMAPtr endp
;
;
;----------------------------------------------------------------------------
;
; procedure : CPMHack
;
; Copies the code from 0:c0 into ffff:0d0h
; for CPM comatibilty
;
;----------------------------------------------------------------------------
;
CPMHack proc near
push ds
mov cx, 0ffffH
mov es, cx ; ES = FFFF
xor cx, cx
mov ds, cx ; DS = 0
mov si, 0c0h
mov di, 0d0h
mov cx, 5
cld
rep movsb ; move 5 bytes from 0:C0 to FFFF:D0
pop ds
ret
CPMHack endp
;
;----------------------------------------------------------------------------
;
; procedure : off_to_para
;
;----------------------------------------------------------------------------
;
off_to_para proc near
shr ax,1
shr ax,1
shr ax,1
shr ax,1
ret
off_to_para endp
;** TempCDS - Create (Temporary?) CDS
;
; ENTRY ?? BUGBUG
; (DS) = SysInitSeg
; EXIT ?? BUGBUG
; USES ?? BUGBUG
public tempcds
Procedure TempCDS
assume ds:sysinitseg
les di,dosinfo
mov cl,byte ptr es:[di.sysi_numio]
xor ch,ch ; (cx) = # of block devices
mov es:[di.sysi_ncds],cl ; one CDS per device
mov al,cl
mov ah,size curdir_list
mul ah ; (ax) = byte size for those CDSs
call pararound ; (ax) = paragraph size for CDSs
mov si,[confbot]
; BUGBUG - we don't update confbot - won't someone else use it?
sub si,ax
mov [alloclim],si ; can't alloc past here!
mov word ptr es:[di.sysi_cds + 2],si
mov ax,si
mov word ptr es:[di.sysi_cds],0 ; set address of CDS list
assume ds:nothing
mov es,ax
xor di,di ; (es:di) = address of 1st CDS
;* Initialize our temporary CDSs.
;
; (cx) = count of CDSs left to process
; (si) = 0 based drive being processed
; (es:di) = address of next CDS
fooset:
xor dx,dx ; indicator to stop removable checks
foogo:
mov ax,word ptr DirStrng
.errnz CURDIR_TEXT ; setup the root as the curdir
stosw
mov ax,word ptr DirStrng+2
stosw
xor ax,ax
push cx
.errnz CURDIR_FLAGS - CURDIR_TEXT - size CURDIR_TEXT
mov cx,curdir_flags - 4
rep stosb ; zero out rest of CURDIR_TEXTs
; Here es:di points to CURDIR_FLAGS
or dx,dx ; have we found one fixed drive?
jnz fixed_drv2 ; NZ -> yes dont do IOCTL check
cmp byte ptr DirStrng, 'B'
jbe not_fixed ; 'A' and 'B' are always removable
mov bl,byte ptr DirStrng
sub bl,'A'
inc bl ; C is 3
mov ax,4408h
int 21h ; Is drive removable
jc fixed_drv ; Could'nt find means NET hence fixed
or ax,ax
jnz fixed_drv
not_fixed:
mov ax,CURDIR_LOCAL OR CURDIR_INUSE
jmp short fill_in
fixed_drv:
inc dx
fixed_drv2:
mov ax,CURDIR_LOCAL OR CURDIR_INUSE OR CURDIR_NT_FIX
fill_in:
FOLLOWS CURDIR_FLAGS,CURDIR_TEXT,2
stosw ; Save Flags
mov ax,2
FOLLOWS CURDIR_END,CURDIR_FLAGS,2
stosw ; Save CURDIR_END
inc byte ptr DirStrng
pop cx
loop foogo
mov byte ptr DirStrng,"A"
ret
EndProc TempCDS
;** EndFile - Build DOS structures
;
; This procedure is called after the config.sys has been processed and
; installable device drivers have been loaded (but before "install="
; programs are loaded) to create the dos structures such as SFTs, buffers,
; FCBs, CDSs, etc. It also loads the sysinit_base module in low memory
; to allow for the safe EXECing of "install=" programs. All memory
; above these structures is deallocated back to DOS.
;
; ENTRY ?? BUGBUG
; EXIT ?? BUGBUG
; USES ?? BUGBUG
;------------------------------------------------------------------------------
; allocate files
;------------------------------------------------------------------------------
endfile:
; we are now setting up final cdss,buffers,files,fcss strings etc. we no
; longer need the space taken by the temp stuff below confbot,so set alloclim
; to confbot.
; if this procedure has been called to take care of install= command,
; then we have to save es,si registers.
push ds
mov ax,Bios_Data
mov ds,ax
assume ds:Bios_Data
cmp multrk_flag,multrk_off1 ;=0,multrack= command entered?
jne multrk_flag_done
or multrk_flag,multrk_on ; default will be on.
multrk_flag_done:
pop ds
assume ds:nothing
mov ax,[confbot]
mov [alloclim],ax
push cs
pop ds
extrn round:near
call round
mov al,[files]
sub al,5
jbe dofcbs
push ax
mov al,devmark_files
call setdevmark ; set devmark for sfts (files)
pop ax
xor ah,ah ; do not use cbw instruction!!!!!
; it does sign extend.
mov bx,[memlo]
mov dx,[memhi]
lds di,dosinfo ;get pointer to dos data
lds di,[di+sysi_sft] ;ds:bp points to sft
mov word ptr [di+sflink],bx
mov word ptr [di+sflink+2],dx ;set pointer to new sft
push cs
pop ds
les di,dword ptr [memlo] ;point to new sft
mov word ptr es:[di+sflink],-1
mov es:[di+sfcount],ax
mov bl,size sf_entry
mul bl ;ax = number of bytes to clear
mov cx,ax
add [memlo],ax ;allocate memory
mov ax,6
add [memlo],ax ;remember the header too
or [setdevmarkflag],for_devmark
call round ; check for mem error before the stosb
add di,ax
xor ax,ax
rep stosb ;clean out the stuff
;------------------------------------------------------------------------------
; allocate fcbs
;------------------------------------------------------------------------------
dofcbs:
push cs
pop ds
call round
mov al,devmark_fcbs ;='x'
call setdevmark
mov al,[fcbs]
xor ah,ah ; do not use cbw instruction!!!!!
; it does sign extend.
mov bx,[memlo]
mov dx,[memhi]
lds di,dosinfo ;get pointer to dos data
assume ds:nothing
mov word ptr [di+sysi_fcb],bx
mov word ptr [di+sysi_fcb+2],dx ;set pointer to new table
mov bl,cs:keep
xor bh,bh
mov [di+sysi_keep],bx
push cs
pop ds
assume ds:sysinitseg
les di,dword ptr [memlo] ;point to new table
mov word ptr es:[di+sflink],-1
mov es:[di+sfcount],ax
mov bl,size sf_entry
mov cx,ax
mul bl ;ax = number of bytes to clear
add [memlo],ax ;allocate memory
mov ax,size sf-2
add [memlo],ax ;remember the header too
or [setdevmarkflag],for_devmark
call round ; check for mem error before the stosb
add di,ax ;skip over header
mov al,"A"
fillloop:
push cx ; save count
mov cx,size sf_entry ; number of bytes to fill
cld
rep stosb ; filled
mov word ptr es:[di-(size sf_entry)+sf_ref_count],0
mov word ptr es:[di-(size sf_entry)+sf_position],0
mov word ptr es:[di-(size sf_entry)+sf_position+2],0
pop cx
loop fillloop
;------------------------------------------------------------------------------
; allocate cdss
;------------------------------------------------------------------------------
buf1:
call round
push ax
mov ax,devmark_cds ;='l'
call setdevmark
pop ax
les di,dosinfo
mov cl,byte ptr es:[di.sysi_numio]
;NTVDM Ignore the lastdrive command. There exists only one cds for all
; network drives and dos has already set sysi_numio to be
; num real drives + 1 for all network drives 17-Aug-1992 Jonle
;
; cmp cl,[num_cds]
; jae gotncds ; user setting must be at least numio
; mov cl,[num_cds]
;gotncds:
;
xor ch,ch
mov es:[di.sysi_ncds],cl
mov ax,[memhi]
mov word ptr es:[di.sysi_cds + 2],ax
mov ax,[memlo]
mov word ptr es:[di.sysi_cds],ax
mov al,cl
mov ah,size curdir_list
mul ah
call pararound
add [memhi],ax
or [setdevmarkflag],for_devmark
call round ; check for mem error before initializing
assume ds:nothing
les di,es:[di.sysi_cds]
call fooset
;------------------------------------------------------------------------------
; allocate space for internal stack
;------------------------------------------------------------------------------
if stacksw
push cs
pop ds
assume ds:sysinitseg
doinstallstack:
mov ax,[stack_count] ; stack_count = 0?
or ax,ax ;then,stack size must be 0 too.
jz skipstack ;don't install stack.
; dynamic relocation of stack code.
call round ;[memhi] = seg. for stack code
;[memlo] = 0
; set devmark block into memory for mem command
; devmark_id = 's' for stack
mov al,devmark_stk ;='s'
call setdevmark
mov ax,[memhi]
mov es,ax ;es -> seg. the stack code is going to move.
assume es:nothing
push cs
pop ds
xor si,si ;!!we know that stack code is at the beginning of sysinit.
xor di,di
mov cx,offset endstackcode
mov [memlo],cx
call round ;have enough space for relocation?
rep movsb
push ds ; stick the location of the NextStack entry
mov ax,Bios_Data ; into the Win386 Instance Data tables
mov ds,ax
assume ds:Bios_Data
mov word ptr NextStack,offset nextentry
mov word ptr NextStack+2,es
mov ax,[memlo]
mov word ptr [stack_addr],ax ;set for stack area initialization
mov word ptr IT_StackLoc,ax ; pass it as Instance Data, too
mov ax,[memhi] ;this will be used by stack_init routine.
mov word ptr [stack_addr+2],ax
mov word ptr IT_StackLoc+2,ax
; space for internal stack area = stack_count(entrysize + stack_size)
mov ax,entrysize
add ax,[stack_size]
mul [stack_count]
mov IT_StackSize,ax ; pass through to Instance Tables
pop ds ; no more need to access Instance Table
assume ds:nothing
call pararound ; convert size to pargraphs
add [memhi],ax
or [setdevmarkflag],for_devmark ;to set the devmark_size for stack by round routine.
call round ; check for memory error before
; continuing
call stackinit ; initialize hardware stack. cs=ds=sysinitseg,es=relocated stack code & data
skipstack:
endif
push cs
pop ds
assume ds:sysinitseg
mov al,[files]
xor ah,ah ; do not use cbw instruction!!!!!
; it does sign extend.
mov cx,ax
xor bx,bx ;close standard input
mov ah,close
int 21h
;; go directly to the handle table; donot close any invalid handles
push si
mov ah, Get_Current_PDB ;
int 21h
les si, es:[pdb_jfn_pointer]
mov bx, 2
rcclloop:
cmp byte ptr es:[bx][si], 0FFh ;skip invalid handle
je skip_the_handle
mov ah,close ; need output so we can print message
int 21h ; in case we can't get new one open.
skip_the_handle:
inc bx
loop rcclloop
pop si
mov dx,offset condev
mov al,2
mov ah,open ;open con for read/write
stc ; set for possible int 24
int 21h
jnc goaux
call badfil
jmp short goaux2
goaux: push ax
mov bx,1 ;close standard output
mov ah,close
int 21h
pop ax
mov bx,ax ;new device handle
mov ah,xdup
int 21h ;dup to 1,stdout
mov ah,xdup
int 21h ;dup to 2,stderr
goaux2: mov dx,offset auxdev
mov al,2 ;read/write access
extrn open_dev:near
call open_dev
mov dx,offset prndev
mov al,1 ;write only
call open_dev
;global rearm command for shared interrupt devices attached in the system;
;shared interrupt attachment has some problem when it issues interrupt
;during a warm reboot. once the interrupt is presented by the attachment,
;no further interrupts on that level will be presented until a global rearm
;is issued. by the request of the system architecture group, msbio will
;issue a global rearm after every device driver is loaded.
;to issue a global rearm: ;for pc1,xt,palace
;
; out 02f2h,xx ; interrupt level 2
; out 02f3h,xx ; interrupt level 3
; out 02f4h,xx ; interrupt level 4
; out 02f5h,xx ; interrupt level 5
; out 02f6h,xx ; interrupt level 6
; out 02f7h,xx ; interrupt level 7
;
; for pc at,in addition to the above commands,
; need to handle the secondary interrupt handler
;
; out 06f2h,xx ; interrupt level 10
; out 06f3h,xx ; interrupt level 11
; out 06f4h,xx ; interrupt level 12
; out 06f6h,xx ; interrupt level 14
; out 06f7h,xx ; interrupt level 15
;
; for round-up machine
;
; none.
; where xx stands for any value.
;
; for your information,after naples level machine,the system service bios
; call (int 15h),function ah=0c0h returns the system configuration parameters
;
;
; Sudeepb 31-Dec-1991 Commented out for NT
if 0
push ax
push bx
push dx
push es
mov al,0ffh ;reset h/w by writing to port
mov dx,2f2h ;get starting address
out dx,al ; out 02f2h,0ffh
inc dx
out dx,al ; out 02f3h,0ffh
inc dx
out dx,al ; out 02f4h,0ffh
inc dx
out dx,al ; out 02f5h,0ffh
inc dx
out dx,al ; out 02f6h,0ffh
inc dx
out dx,al ; out 02f7h,0ffh
;sb secondary global rearm
mov ax,0f000h ;get machine type
mov es,ax
cmp byte ptr es:[0fffeh],0fch ;q:is it a at type machine
je startrearm ; *if at no need to check
mov ah,0c0h ;get system configuration
int 15h ; *
jc finishrearm ; *jmp if old rom
; test feature byte for secondary interrupt controller
test es:[bx.bios_sd_featurebyte1],scndintcontroller
je finishrearm ;jmp if it is there
startrearm:
mov al,0ffh ;write any pattern to port
mov dx,6f2h ;get starting address
out dx,al ;out 06f2h,0ffh
inc dx ;bump address
out dx,al ;out 06f3h,0ffh
inc dx ;bump address
out dx,al ;out 06f4h,0ffh
inc dx ;bump address
inc dx ;bump address
out dx,al ;out 06f6h,0ffh
inc dx ;bump address
out dx,al ;out 06f7h,0ffh
finishrearm:
pop es
pop dx
pop bx
pop ax
endif
; global rearm end *******************
;------------------------------------------------------------------------------
; allocate sysinit_base for install= command
;------------------------------------------------------------------------------
; sysinit_base allocation.
; check if endfile has been called to handle install= command.
set_sysinit_base:
;--------------------------------------------------------------------------
;sysinit_base will be established in the secure area of
;lower memory when it handles the first install= command.
;sysinit_base is the place where the actual exec function will be called and
;will check sysinit module in high memory if it is damaged by the application
;program. if sysinit module has been broken,then "memory error..." message
;is displayed by sysinit_base.
;--------------------------------------------------------------------------
push ax ; set devmark for mem command
mov ax,[memhi]
sub ax,[area]
mov [impossible_owner_size],ax ;remember the size in case.
mov al,devmark_inst
call setdevmark
pop ax
mov di,[memhi]
mov es,di
assume es:nothing
mov word ptr [sysinit_base_ptr+2],di ; save this entry for the next use.
xor di,di
mov word ptr [sysinit_base_ptr],di ; es:di -> destination.
mov si,offset sysinit_base ;ds:si -> source code to be relocated.
mov cx,(offset end_sysinit_base) - (offset sysinit_base)
add [memlo],cx
or cs:[setdevmarkflag],for_devmark
call round ; check mem error. also,readjust memhi for the next use.
rep movsb ; reallocate it.
mov word ptr [sysinit_ptr],offset sysinitptr ; returing address from
mov word ptr [sysinit_ptr+2],cs ; sysinit_base back to sysinit.
or [install_flag],has_installed ; set the flag.
;------------------------------------------------------------------------------
; free the rest of the memory from memhi to confbot. still from confbot to
; the top of the memory will be allocated for sysinit and config.sys if
; have_install_cmd.
;------------------------------------------------------------------------------
call round
mov bx,[memhi]
mov ax,[area]
mov [old_area],ax ; save [area]
mov es,ax ;calc what we needed
sub bx,ax
mov ah,setblock
int 21h ;give the rest back
push es
mov ax,es
dec ax
mov es,ax ;point to arena
mov es:[arena_owner],8 ;set impossible owner
mov word ptr es:[arena_name], 'DS' ; System Data
pop es
mov bx,0ffffh
mov ah,alloc
int 21h
mov ah,alloc
int 21h ; allocate the rest of the memory
mov [memhi],ax ; start of the allocated memory
mov [memlo],0 ; to be used next.
;;;; at this moment,memory from [memhi]:0 to top-of-the memory is
;;;; allocated.
;;;; to protect sysinit,confbot module (from confbot (or =alloclim at
;;;; this time) to the top-of-the memory),here we are going to
;;;; 1). "setblock" from memhi to confbot.
;;;; 2). "alloc" from confbot to the top of the memory.
;;;; 3). "free alloc memory" from memhi to confbot.
;memory allocation for sysinit,confbot module.
mov es,ax
mov bx,[confbot]
sub bx,ax ; confbot - memhi
dec bx ; make a room for the memory block id.
dec bx ; make sure!!!.
mov ah,setblock
int 21h ; this will free (confbot to top of memory)
mov bx,0ffffh
mov ah,alloc
int 21h
mov ah,alloc
int 21h ; allocate (confbot to top of memory)
mov [area],ax ; save allocated memory segment.
; need this to free this area for command.com.
mov es,[memhi]
mov ah,49h ; free allocated memory.
int 21h ; free (memhi to confbot(=area))
endfile_ret:
ret
; End of "EndFile" DOS structure configuration.
;-------------------------------------------------------------------------
; Do_Install_Exec
;
; This procedure is used to EXEC a program being loaded via the
; "install=" mechanism in config.sys. It does this by setting up
; the parameters, and then jumping to sysinit_base, which has been
; setup in low memory. When complete, sysinit_base will jump back
; up to this procedure (if sysinit remains uncorrupted by the installed
; program).
do_install_exec proc near ; now,handles install= command.
push si ; save si for config.sys again.
; we are going to call load/exec function.
; set es:bx to the parameter block here;;;;;;;
; set ds:dx to the asciiz string. remember that we already has 0
; after the filename. so parameter starts after that. if next
; character is a line feed (i.e. 10),then assume that the 0
; we already encountered used to be a carrage return. in this
; case,let's set the length to 0 which will be followed by
; carridge return.
; es:si -> command line in config.sys. points to the first non blank
;character after =.
push es
push ds
pop es
pop ds ; es->sysinitseg,ds->confbot seg
assume ds:nothing
mov dx,si ; ds:dx->file name,0 in config.sys image.
xor cx,cx
cld
mov cs:ldexec_start,' ' ; clear out the parm area
mov di,offset ldexec_parm
installfilename: ; skip the file name
lodsb ; al = ds:si; si++
cmp al,0
je got_installparm
jmp installfilename
got_installparm: ; copy the parameters to ldexec_parm
lodsb
mov es:[di],al
cmp al,lf ; line feed?
je done_installparm
inc cl ; # of char. in the parm.
inc di
jmp got_installparm
done_installparm:
mov byte ptr cs:[ldexec_line],cl ; length of the parm.
cmp cl,0 ;if no parm,then
jne install_seg_set ; let the parm area
mov byte ptr cs:[ldexec_start],cr ; starts with cr.
install_seg_set:
mov word ptr cs:0,0 ; make a null environment segment
mov ax,cs ; by overlap jmp instruction of sysinitseg.
;hkn; the environment pointer is made 0. so the current environment ptr.
;hkn; will be the same as pdb_environ which after dosinit is 0.
mov cs:[instexe.exec0_environ],0 ; set the environment seg.
mov word ptr cs:[instexe.exec0_com_line+2],ax ; set the seg.
mov word ptr cs:[instexe.exec0_5c_fcb+2],ax
mov word ptr cs:[instexe.exec0_6c_fcb+2],ax
call sum_up
mov es:checksum,ax ; save the value of the sum
xor ax,ax
mov ah,exec ; load/exec
mov bx,offset instexe ; es:bx -> parm block.
push es ; save es,ds for load/exec
push ds ; these registers will be restored in sysinit_base.
jmp cs:dword ptr sysinit_base_ptr ; jmp to sysinit_base to execute
; load/exec function and check sum.
;j.k. this is the returning address from sysinit_base.
sysinitptr: ; returning far address from sysinit_base
pop si ; restore si for config.sys file.
push es
push ds
pop es
pop ds ; now ds - sysinitseg,es - confbot
jnc exec_exit_code
push si ; error in loading the file for install=.
call badload ; es:si-> path,filename,0.
pop si
jmp short install_exit_ret
exec_exit_code:
mov ah,4dh
int 21h
cmp ah,3 ;only accept "stay resident" prog.
je install_exit_ret
call error_line ;inform the user
stc
install_exit_ret:
ret
do_install_exec endp
;** ParaRound - Round Up length to paragraph multiple
;
; ParaRound rounds a byte count up to a multiple of 16, then divides
; by 16 yielding a "length in paragraphs" value.
;
; ENTRY (ax) = byte length
; EXIT (ax) = rounded up length in paragraphs
; USES ax, flags
Procedure ParaRound
add ax,15
rcr ax,1
shr ax,1
shr ax,1
shr ax,1
ret
EndProc ParaRound
;------------------------------------------------------------------------------
; sysinit_base module.
;
; This module is relocated by the routine EndFile to a location in low
; memory. It is then called by SYSINIT to perform the EXEC of programs
; that are being loaded by the "install=" command. After the EXEC call
; completes, this module performs a checksum on the SYSINIT code (at the
; top of memory) to be sure that the EXECed program did not damage it.
; If it did, then this module will print an error message and stop the
; system. Otherwise, it returns control to SYSINIT.
;
;
;in: after relocation,
; ax = 4b00h - load and execute the program dos function.
; ds = confbot. segment of config.sys file image
; es = sysinitseg. segment of sysinit module itself.
; ds:dx = pointer to asciiz string of the path,filename to be executed.
; es:bx = pointer to a parameter block for load.
; SI_end (byte) - offset vaule of end of sysinit module label
; bigsize (word) - # of word from confbot to SI_end.
; chksum (word) - sum of every byte from confbot to SI_end in a
; word boundary moduler form.
; sysinit_ptr (dword ptr) - return address to sysinit module.
;
;note: sysinit should save necessary registers and when the control is back
public sysinit_base
sysinit_base:
mov word ptr cs:sysinit_base_ss,ss ; save stack
mov word ptr cs:sysinit_base_sp,sp
int 21h ; load/exec dos call.
mov ss,word ptr cs:sysinit_base_ss ; restore stack
mov sp,word ptr cs:sysinit_base_sp
pop ds ; restore confbot seg
pop es ; restore sysinitseg
jc sysinit_base_end ; load/exec function failed.
; at this time,i don't have to worry about
; that sysinit module has been broken or not.
call sum_up ; otherwise,check if it is good.
cmp es:checksum,ax
je sysinit_base_end
; memory broken. show "memory allocation error" message and stall.
mov ah,9
push cs
pop ds
mov dx,offset mem_alloc_err_msgx - sysinit_base
int 21h
jmp $ ; hang here!!!!
sysinit_base_end: jmp es:sysinit_ptr ;return back to sysinit module
sum_up:
;in: es - sysinitseg.
;out: ax - result
;
;remark: since this routine will only check starting from "locstack" to the end of
; sysinit segment,the data area, and the current stack area are not
; coverd. in this sense,this check sum routine only gives a minimal
; gaurantee to be safe.
;
;first sum up confbot seg.
push ds
mov ax,es:confbot
mov ds,ax
xor si,si
xor ax,ax
mov cx,es:config_size ; if config_size has been broken,then this
;whole test better fail.
shr cx,1 ; make it a word count
jz sum_sys_code ; when config.sys file not exist.
sum1:
add ax,ds:word ptr [si]
inc si
inc si
loop sum1
;now,sum up sysinit module.
sum_sys_code:
mov si,offset locstack ; starting after the stack.
; this does not cover the possible stack code!!!
mov cx,offset sysinitgrp:SI_end ; SI_end is the label at the end of sysinit
sub cx,si ; from after_checksum to SI_end
shr cx,1
sum2:
add ax,es:word ptr [si]
inc si
inc si
loop sum2
pop ds
ret
sysinit_base_ss equ $-sysinit_base
dw ?
sysinit_base_sp equ $-sysinit_base
dw ?
mem_alloc_err_msgx:
include msbio.cl4 ; memory allocation error message
end_sysinit_base label byte
;------------------------------------------------------------------------------
; ibmstack initialization routine.
if stacksw
.sall
;
; to follow the standard interrupt sharing scheme, msstack.asm
; has been modified. this initialization routine also has to
; be modified because for the interrupt level 7 and 15, firstflag
; should be set to signal that this interrupt handler is the
; first handler hooked to this interrupt vector.
; we determine this by looking at the instruction pointed by
; this vector. if it is iret, then this handler should be the
; first one. in our case, only the interrupt vector 77h is the
; interrupt level 15. (we don't hook interrupt level 7.)
;
; the followings are mainly due to m.r.t; ptm fix of p886 12/3/86
; some design changes are needed to the above interrupt sharing
; method. the above sharing scheme assumes that 1). interrupt
; sharing is never done on levels that have bios support. 2). "phantom"
; interrupts would only be generated on levels 7 and 15.
; these assumptions are not true any more. we have to use the firstflag
; for every level of interrupt. we will set the firstflag on the following
; conditions:
;
; a. if the cs portion of the vector is 0000, then "first"
; b. else if cs:ip points to valid shared header, then not "first"
; c. else if cs:ip points to an iret, then "first"
; d. else if cs:ip points to dummy, then "first"
;
; where dummy is - the cs portion must be f000, and the ip portion must
; be equal to the value at f000:ff01. this location is the initial value
; from vector_table for interrupt 7, one of the preserved addresses in all
; the bioses for all of the machines.
;
; system design group requests bios to handle the phantom interrupts.
;
; the "phantom" interrupt is an illegal interrupt such as an interrupt
; produced by the bogus adapter card even without interrupt request is
; set. more specifically, 1). the 8259 has a feature when running in
; edge triggered mode to latch a pulse and present the interrupt when
; the processor indicates interrupt acknowledge (inta). the interrupt
; pulse was exist at the time of inta to get a "phantom" interrupt.
; 2). or, this is caused by adapter cards placing a glitch on the
; interrupt line.
;
; to handle those "phantom" interrupts, the main stack code will check
; the own firstflag, and if it is not "first" (which means the forward
; pointer points to the legal shared interrupt handler), then pass the
; control. if it is the first, then the following action should be
; taken. we don't have to implement skack logic in this case.
;
; to implement this logic, we rather choose a simple method.
; if ont of the above "firstflag" conditions is met, we are not
; going to hook this interrupt vector. the reason is if the original
; vector points to "iret" and do nothing, we don't need
; to implement the stack logic for it. this will simplify implementation
; while maintaining compatibility with the old version of dos.
; this implies that in the main stack code, there might be a stack code
; that will never be used, a dead code.
;
;in - cs, ds -> sysinitseg, es -> relocated stack code & data.
page
assume ds:sysinitseg
stackinit proc near
push ax
push ds
push es
push bx
push cx
push dx
push di
push si
push bp
;currently es -> stack code area
mov ax, cs:[stack_count] ;defined in cs
mov es:[stackcount], ax ;defined in stack code area
mov ax, [stack_size] ;in cs
mov es:[stacksize], ax
mov ax, word ptr cs:[stack_addr] ; offset
mov word ptr es:[stacks], ax
mov ax, word ptr cs:[stack_addr+word] ; segment
mov word ptr es:[stacks+word], ax
; initialize the data fields with the parameters
; "firstentry" will always be at stacks
mov bp, word ptr es:stacks ; get offset of stack
mov es:firstentry,bp
; the stacks will always immediately follow the table entries
mov ax,entrysize
mov cx,es:stackcount
mul cx
add ax,bp
mov es:stackat,ax
mov bx,ax
sub bx,2
; zero the entire stack area to start with
mov di,es:stackat
mov ax,es:stacksize
mul cx
mov cx,ax
xor ax,ax
push es
pop ds ;ds = relocated stack code seg.
assume ds:nothing
;now, ds -> stack code area
mov es, word ptr ds:[stacks+2] ; get segment of stack area.
cld
rep stosb
mov cx, ds:stackcount
; loop for "count" times, building a table entry
; cs = sysinitseg, ds = relocated stack code seg , es = segment of stack space
; cx = number of entries
; es:bp => base of stacks - 2
; es:bx => first table entry
buildloop:
mov es:byte ptr allocbyte[bp],free
mov es:byte ptr intlevel[bp],al ;ax = 0
mov es:word ptr savedsp[bp],ax
mov es:word ptr savedss[bp],ax
add bx,ds:stacksize
mov es:word ptr newsp[bp],bx
mov es:[bx],bp
add bp,entrysize
loop buildloop
sub bp,entrysize
mov ds:lastentry,bp
mov ds:nextentry,bp
; NTVDM support for pc convertable is NOT NEEDED 10-Aug-1992 Jonle
; push ds
; mov ax, 0f000h ;look at the model byte
; mov ds, ax
; cmp ds:byte ptr [0fffeh], mdl_convert ;convertible?
; pop ds
; jne skip_disablenmis
;
; mov al,07h ; disable convertible nmis
; out 72h,al
;
;skip_disablenmis:
xor ax,ax
mov es,ax ;es - segid of vector table at 0
assume es:nothing ;ds - relocated stack code segment
call DOCLI
irp aa,<02,70>
mov si,aa&h*4 ;pass where vector is to be adjusted
mov di, offset int19old&aa ;we have to set old&aa for int19 handler too.
mov bx,offset old&aa ;pass where to save original owner pointer
mov dx,offset int&aa ;pass where new handler is
call new_init_loop ;adjust the vector to new handler,
; saving pointer to original owner
endm
; NTVDM int 08, 09, special handling 24-Jan-1993 Jonle
;
; These Ints are usually done in the macro above with int 02,70
; However, we don't need stack swapping as long as no device
; driver has hooked it. These ints are also left alone so that
; softpc will know if they have been hooked by an app.
mov si, 09h*4
mov ax, word ptr es:[si+0]
cmp word ptr old09, ax
jne do_I9StkSwap
mov ax, word ptr es:[si+2]
cmp word ptr old09+2, ax
je skip_I9StkSwap
do_I9StkSwap:
mov di, offset int19old09
mov bx,offset old09
mov dx,offset int09
call new_init_loop
skip_I9StkSwap:
mov si, 08h*4
mov ax, word ptr es:[si+0]
cmp word ptr old08, ax
jne do_I8StkSwap
mov ax, word ptr es:[si+2]
cmp word ptr old08+2, ax
je skip_I8StkSwap
do_I8StkSwap:
mov di, offset int19old08
mov bx,offset old08
mov dx,offset int08
call new_init_loop
skip_I8StkSwap:
irp aa,<0a,0b,0c,0d,0e,72,73,74,76,77> ;shared interrupts
mov si,aa&h*4 ;pass where vector is to be adjusted
push ds ;save relocated stack code segment
lds bx, es:[si] ;ds:bx -> original interrupt handler
push ds
pop dx ;dx = segment value
cmp dx,0
jz int&aa&_first
cmp byte ptr ds:[bx],0cfh ;does vector point to an iret?
jz int&aa&_first
cmp word ptr ds:[bx.6],424bh ;magic offset (see int&aa, msstack.inc)
jz int&aa&_not_first
cmp dx,0f000h ;rom bios segment
jnz int&aa&_not_first
push es
push dx
mov dx,0f000h
mov es,dx
cmp bx,word ptr es:0ff01h
pop dx
pop es
jz int&aa&_first
int&aa&_not_first: ;not the first. we are going to hook vector.
pop ds
mov di, offset int19old&aa ;we have to set old&aa for int19 handler too.
mov bx, offset old&aa ;pass where to save original owner pointer
mov dx, offset int&aa ;pass where new handler is
call new_init_loop ;adjust the vector to new handler, saving
;pointer to original owner.
jmp short int&aa&_end
int&aa&_first: ;the first. don't have to hook stack code.
pop ds
int&aa&_end:
endm
; NTVDM support for pc convertable is NOT NEEDED 10-Aug-1992 Jonle
; push ds
; mov ax, 0f000h ;loook at the model byte
; mov ds, ax
; cmp ds:byte ptr [0fffeh], mdl_convert ;pc convertible?
; pop ds
; jne skip_enablenmis
;
; mov al,27h ; enable convertible nmis
; out 72h,al
;
; skip_enablenmis:
call DOSTI
mov ax,Bios_Data
mov ds,ax
assume ds:Bios_Data
mov [int19sem],1 ; indicate that int 19
; initialization is complete
pop bp ; restore all
pop si
pop di
pop dx
pop cx
pop bx
pop es
pop ds
assume ds:sysinitseg
pop ax
ret
stackinit endp
new_init_loop proc near
;input: si=ofset into vector table of the particular int vector being adjusted
; bx=ds:offset of oldxx, where will be saved the pointer to original owner
; dx=ds:offset of intxx, the new interrupt handler
; di=offset value of int19old&aa variable in bios.
; es=zero, segid of vector table
; ds=relocated stack code segment
mov ax,es:[si+0] ;remember offset in vector
mov word ptr ds:[bx],ax ; to original owner in ds
mov ax,es:[si+2] ;remember segid in vector
mov word ptr ds:[bx]+2,ax ; to original owner in ds
push ds
mov ax,Bios_Data
mov ds,ax ;set int19oldxx value in bios for
mov ax,es:[si+0] ;int 19 handler
mov word ptr ds:[di],ax
mov ax,es:[si+2]
mov word ptr ds:[di]+2,ax
pop ds
mov word ptr es:[si+0],dx ;set vector to point to new int handler
mov es:[si+2],ds
ret
new_init_loop endp
.xall
endif
;------------------------------------------------------------------------------
public setdevmark
setdevmark proc
;set the devmark for mem command.
;in: [memhi] - the address to place devmark
; [memlo] = 0
; al = id for devmark_id
;out: devmark established.
; the address saved in cs:[devmark_addr]
; [memhi] increase by 1.
push es
push cx
mov cx,cs:[memhi]
mov cs:[devmark_addr],cx
mov es,cx
mov es:[devmark_id],al
inc cx
mov es:[devmark_seg],cx
pop cx
pop es
inc cs:[memhi]
ret
setdevmark endp
ifdef TAIWAN
;---------------------
; entry : none
; exit : ax = 0 --> oem local driver not found
; = 1 --> oem local driver found
; destore : ds,es,bx,cx,dx,si,di
; description :
; search config.sys to find oem local driver.
; oem local driver should in \csi\driver\ directory .
; if (found oem local driver in config.sys)
; ax=1;
; else
; ax=0;
; return;
; ps. please see state diagram for state description.
;---------------------
chkoemlocaldrv proc near
push es
push ds
push bx
push cx
push dx
push di
push si
call chkconfig
pop si
pop di
pop dx
pop cx
pop bx
pop ds
pop es
ret
chkoemlocaldrv endp
config_sys db "C:\CONFIG.SYS",0
sizeofconfig dw 0
filehandle dw 0
workingmemptr dw 0
deviceid db "DEVICE"
csidrvid db "CSI\DRIVER\"
localdrvname dw 0
chkconfig proc near
call preprocess
jnc initstate
jmp notfoundret
;
; processing config.sys
;
; state 0
; ds:si --> current line ( end of line is oah or 0dh )
initstate:
mov si,dx
state_0:
push cs
pop es
mov di,offset deviceid
mov cx,3
repz cmpsw
jz state_1
mov ax,0ffffh
jmp state_10
state_1:
lodsb
cmp al,' '
jz state_1
cmp al,'='
jz state_2
state_10a:
jmp state_10
state_2:
lodsb
cmp al,' '
jz state_2
cmp al,'\'
jz state_5
cmp al,'A'
jb state_10a
cmp al,'z'
ja state_10a
state_3:
dec si
mov cs:[localdrvname],si
inc si
state_4:
lodsb
cmp al,':'
jz state_6
jmp state_10
state_5:
dec si
mov cs:[localdrvname],si
inc si
jmp state_7
state_6:
lodsb
cmp al,'\'
jz state_7
cmp al,'c'
jne state_10a
inc si
state_7:
mov di,offset csidrvid
mov cx,11
repz cmpsb
jnz state_10a
state_8:
lodsb
cmp al,'1'
jb state_10
cmp al,'z'
ja state_10
state_9:
tryopenlocaldrv:
mov dx,cs:[localdrvname]
mov si,dx
chknextbyte:
lodsb
cmp al,0h
jz openfile
cmp al,' '
jne chknextbyte
dec si
mov byte ptr ds:[si],0
openfile:
mov ax,3d00h ; open config.sys
stc
int 21h
jc notfoundret
mov bx,ax ; bx = file handle
mov ah,3eh
int 21h ; close local driver
jc notfoundret
jmp foundret
state_10:
cmp al,1ah ; look current char. == eof ?
jz notfoundret
lodsb
cmp al,0
jz newlinestate
cmp al,1ah
jz notfoundret
jmp state_10
newlinestate:
lodsb
cmp al,1ah
jz notfoundret
cmp al,0
jz newlinestate
dec si
jmp state_0
notfoundret:
mov ax,0
jmp freemem
foundret:
mov ax,1
freemem:
push ax
call freememory
pop ax
ret
chkconfig endp
preprocess proc near
push cs
pop ds
mov dx,offset config_sys
mov ax,3d00h ; open config.sys
stc
int 21h
jc errorfile
; get size of config.sys
mov bx,ax ; bx = file handle
mov cs:[filehandle],bx
xor cx,cx
xor dx,dx
mov ax,4202h ; move file ptr
int 21h
mov cs:[sizeofconfig],ax ; ax == size of config.sys
xor dx,dx ; ignore more than 64k of config
mov ax,4200h ; mov file ptr to beginning of file
int 21h
; allocate for config.sys
mov ax,cs:[sizeofconfig]
add ax,15 ; change to para
rcr ax,1
shr ax,1
shr ax,1
shr ax,1
add ax,20h
mov bx,ax ; size of memory in para
mov ah,48h
int 21h
jc memerr
; ax --> free memory
mov cs:[workingmemptr],ax
; read config.sys
mov bx,cs:[filehandle] ; file handle
mov cx,cs:[sizeofconfig] ; byte count of reading
xor dx,dx
mov ds,ax ; ds:dx --> buffer
mov ah,3fh
int 21h
jc errorfile
; translate to upper case
call transtoupper
clc
ret
errorfile:
memerr:
stc
ret
preprocess endp
; entry : ds:dx --> buffer
; exit : none
; description : translate all letter in buffer to upper type
; ps ,don't change ds:dx
transtoupper proc near
cld
mov cx,cs:[sizeofconfig]
mov si,dx
transnext:
lodsb
cmp al,'A'
jb chklfcr
cmp al,'z'
ja chkcounter
sub al,'a'-'A'
mov ds:[si-1],al
jmp chkcounter
chklfcr:
cmp al,0dh
jz setzero
cmp al,0ah
jz setzero
jmp chkcounter
setzero:
mov al,0
mov ds:[si-1],al
chkcounter:
loop transnext
ret
transtoupper endp
;entry : none ( free memory block ptr in [workingmem] )
;exit : none
freememory proc near
mov ax,cs:[workingmemptr]
mov es,ax
mov ah,49h
int 21h
ret
freememory endp
; name : maketempvector
; entry : es:bx -->
; dd original int 9 vector ( offfset ,segment )
; dd original int 10h vector ( offfset ,segment )
; dd original int 16h vector ( offfset ,segment )
;
; exit : none
; description : 1. save local driver table in static area
; 2. make temp. vector for int9 ,10h ,16h
;
oemdriverinst dw 0
orgvectblptr dd 0
db 0eah
dummyint9 dd 0
db 0eah
dummyint10h dd 0
db 0eah
dummyint16h dd 0
csiint9 dd 0
csiint10h dd 0
csiint16h dd 0
maketempvector proc near
push ds
push ax
push di
push si
push cx
; save table ptr
mov word ptr cs:[orgvectblptr],bx
mov word ptr cs:[orgvectblptr+2],es
cmp cs:oemdriverinst,0
jnz ignoreint9
; make temp. vector for int 9 ,
mov bx,9 ; int #
push cs
pop es
mov di,offset csiint9 ; es:di --> store area for csi vector
push cs
pop ds
mov si,offset dummyint9 ; ds:si --> dummy int service
call dummyvector
ignoreint9:
; make temp. vector for int 10h
mov bx,10h ; int #
push cs
pop es
mov di,offset csiint10h ; es:di --> store area for csi vector
push cs
pop ds
mov si,offset dummyint10h ; ds:si --> dummy int service
call dummyvector
; make temp. vector for int 16h
mov bx,16h ; int #
push cs
pop es
mov di,offset csiint16h ; es:di --> store area for csi vector
push cs
pop ds
mov si,offset dummyint16h ; ds:si --> dummy int service
call dummyvector
pop cx
pop si
pop di
pop ax
pop ds
ret
maketempvector endp
;name : dummyvector
; entey : ds:si --> dummy int sevice routine
; es:di --> point to csi vector store area
; bx == int number
; exit : none
; description :
; setting dummy vector of int 9 ,10h,16h
; for recover csi vector
; /* phase 1*/
; [ds:si]=[0:bx*4]
; [ds:si+2]=[0:bx*4+2]
; /* phase 2*/
; [es:di]=[0:bx*4]
; [es:di+2]=[0:bx*4+2]
; /* phase 2*/
; [0:bx*4]=si-1;
; [0:bx*4+2]=ds;
dummyvector proc near
shl bx,1 ; bx <- bx*4
shl bx,1 ; ie ,get offset of vector
; phase 1
; es --> 0
; es:bx --> cpu int vector table
xor ax,ax
push es
mov es,ax
mov ax,es:[bx] ; get offset ds-->0
mov ds:[si],ax ; store offset
mov ax,es:[bx+2] ; get offset ds-->0
mov ds:[si+2],ax ; store segment
pop es
; phase 2
; ds --> 0
; ds:bx --> cpu int vector table
xor ax,ax
push ds
mov ds,ax
mov ax,ds:[bx] ; get offset
mov es:[di],ax ; store offset
mov ax,ds:[bx+2] ; get offset
mov es:[di+2],ax ; store segment
pop ds
; phase 3
; es --> 0
; es:bx --> cpu int vector table
xor ax,ax
push es
mov es,ax
dec si
mov es:[bx],si
mov ax,ds
mov es:[bx+2],ax
pop es
ret
dummyvector endp
; name : recovercsiint
; entry : none
; exit :none
; description :
; recover int 9 ,10h,16h ,for csi vector
recovercsiint proc near
push es
push ds
push ax
push bx
push cx
push dx
push si
push di
;recover int 9
cmp cs:oemdriverinst,0
jnz ignoreint9recover
push cs
pop ds
mov si,offset dummyint9
push cs
pop es
mov di,offset csiint9
mov bx,9
mov ax,0
call recoverint
ignoreint9recover:
; recover int 10h
push cs
pop ds
mov si,offset dummyint10h
push cs
pop es
mov di,offset csiint10h
mov bx,10h
mov ax,0+4
call recoverint
;recover int 16h
push cs
pop ds
mov si,offset dummyint16h
push cs
pop es
mov di,offset csiint16h
mov bx,16h
mov ax,0+4+4
call recoverint
pop di
pop si
pop dx
pop cx
pop bx
pop ax
pop ds
pop es
ret
recovercsiint endp
; name : recoverint
; entey : ds:si --> dummy int sevice routine
; es:di --> point to csi vector store area
; bx == int number
; ax == 0 ; int 9
; 4 ; int 10h
; 4+4 ; int 16h
; exit : none
; description :
; 1. if( [0:bx*4] == si-1 .and. [es:bx*4+2] == ds )
; {
; [0:bx*4] = [es:di];
; [0:bx*4+2] = [es:di+2];
; }
; else
; {
; /* phase 1 */
; [ds:si] = [(*orgvectblptr)+ax]
; [ds:si+2]= [(*orgvectblptr)+ax+2];
; /* phase 2 */
; [orgvectblptr+ax) ]=[0:bx*4] ;
; [orgvectblptr+ax+2 ]=[0:bx*4+2] ;
; /* phase 3 */
; [0:bx*4] = [es:di];
; [0:bx*4+2] = [es:di+2];
;
;
; }
;
recoverint proc near
;chek vector change ?
; es --> 0
push es
mov cx,ax
xor ax,ax
mov es,ax
shl bx,1
shl bx,1 ; es:bx --> cpu int vector
mov ax,si
dec ax
cmp es:[bx],ax ; offset same ?
jne vectorbechanged
mov ax,ds
cmp es:[bx+2],ax ; segmnet same ?
jne vectorbechanged
pop es
; vector not be changed
; ds --> 0
xor ax,ax
mov ds,ax ; ds:bx --> cpu int vector
mov ax,es:[di]
mov ds:[bx],ax
mov ax,es:[di+2]
mov ds:[bx+2],ax
ret
vectorbechanged:
;phase 1
; di:es --> addres of local driver
pop es
push di
push es
mov di,word ptr cs:[orgvectblptr]
mov es,word ptr cs:[orgvectblptr+2]
add di,cx
mov ax,es:[di]
mov ds:[si],ax
mov ax,es:[di+2]
mov ds:[si+2],ax
;phase2
; di:es --> addres of local driver
; ds --> 0
push ds
xor ax,ax
mov ds,ax
mov ax,ds:[bx] ; ds:bx --> cpu int vector
mov es:[di],ax
mov ax,ds:[bx+2]
mov es:[di+2],ax
pop ds
pop es
pop di
;phase3
; ds --> 0
xor ax,ax
push ds
mov ds,ax
mov cx,es:[di]
mov ds:[bx],cx ; ds:bx --> cpu int vector
mov cx,es:[di+2]
mov ds:[bx+2],cx
pop ds
ret
recoverint endp
;name : chklocalexist
;entry : none
;exit :none
; descriptin : check local driver exist ?
; if not exist system halt !
; otherwise null return
chklocalexist proc near
push ax
push cx
push dx
mov ah,0dbh
mov al,80h ; module_extsysutil
mov cx,01 ; syscmd_extquerysysmode
int 16h
test ax,8000h ; bit 15 on
jnz csisystemerror ; no,system halt
; yes ,dx == country id
push dx ; save current id
mov dx,58h
mov ah,0dbh
mov al,80h ; module_extsysutil
mov cx,02 ; syscmd_extsetsysmode
int 16h
test ax,8000h ; bit 15 on
jnz localdrvnotfound ; no ,local driver error
pop cx
cmp cx,dx ; current id == previous id ?
jnz localdrvnotfound ; no ,local driver error
pop dx
pop cx
pop ax
ret
localdrvnotfound:
csisystemerror:
push cs
pop ds
mov dx,offset bootfailmsg
mov ah,9
int 21h
cli
hlt
ret
chklocalexist endp
endif
sysinitseg ends
end