page      60,132
NAME           cmosrest
               title     CMOSChk Check that CMOS is relatively unmodified since last use of CMOSSave
Comment |
        Version 4.7 by Roedy Green
        works with MASM 6.0 and Optasm
Note that we never compute or verify a checksum.  Every vendor computes
may compute it a slightly different way.
To come:
  /V:xx - additional volatile byte
See CMOS.TXT for details on use.
  USAGE:
Examples:
*********
CMOSSave A:\MyCMOS.Sav /Q
CMOSRest A:\MyCMOS.Sav /Q
CMOSChk  A:\ByCMOS.Sav /Q
These are DOS utilities and thus can only use short 8.3 file names.
Syntax errors or missing file trouble generates an ERRORLEVEL 4.
CMOSChk generates an ERRORLEVEL 1 if the CMOS has changed since
the CMOSSave was done.
Please report bugs and problems to:
Roedy Green
Canadian Mind Products
#101 - 2536 Wark Street
Victoria, BC Canada V8T 4G8
tel:(250) 361-9093
mailto:roedyg@mindprod.com
http://mindprod.com
Version History
***************
see cmossave.asm
CMOS Usage - see also CMOS.OFS
How to Assemble
***************
use the ANT script or
to assemble with MASM 6.0 use:
ml.exe /AT /c /Fl  /Zf cmoschk.asm
link.exe /TINY /MAP cmoschk.Obj,cmoschk.com,cmoschk.map;
copy cmos.com cmossave.com
to assemble with OPTASM use:
Optasm   cmoschk.asm,cmoschk.obj,cmoschk.lst/L/N/G/S
OLINK    cmoschk.obj,cmoschk.com,/MAP/TINY;
Register Conventions
********************
Subroutines may trash all registers except those explicity
documented as input or output.
|                                        ; end of comment
;==============================================================
stack          segment   stack          ; keep MS link happy by providing null stack
stack          ends
CODE           segment   PARA           ; start off in code.
;==============================================================
data           segment   byte           ; provide a separate DATA segment
                                        ; actually all come after the code
;==============================================================
;  V A R I A B L E S
BannerMsg      label     byte
               db        '°±²Û CMOSChk 4.6 Û²±°',13d,10d
               db        13d,10d
               db        'Ensures CMOS not corrupted or changed.',13,10
               db        'Copyright: (c) 1991-2017 Roedy Green, Canadian Mind Products.',13,10
               db        '#101 - 2536 Wark Street, Victoria, BC Canada V8T 4G8',13,10
               db        'tel:(250) 361-9093   mailto:roedyg@mindprod.com   http://mindprod.com',13,10
               db        'Freeware to freely distribute and use for any purpose except military.',13,10
               db        13,10
               db        '$'
UsageMsg       db        '°±²Û Error Û²±°',7,13,10
               db        'Insert the diskette you used for CMOSSave.',13,10
               db        'then try:',13,10
               db        'CMOSChk A:\CMOS.Sav',13,10
               db        'or if you have the file on hard disk try:',13,10
               db        'CMOSChk C:\SAFE\CMOS.Sav',13,10
               db        'CMOSChk is a DOS utility, and thus can only use short 8.3 file names',13,10
               db        'Read CMOS.TXT to find how to use it properly.',13,10
               db        '$'
FileTroubleMsg db        '°±²Û Error Û²±°',7,13,10
               db        'Cannot find/read the disk file.',13,10
               db        '$'
MatchTroubleMsg db       '°±²Û Error Û²±°',7,13,10
               db        'CMOS has been corrupted! at hex offset:value:expected ',13,10
               db        '$'
ColonMsg       db        ':','$'
NextTripleMsg  db        13,10,'$'
WorkedMsg      db        'CMOS is OK, i.e. unchanged since the last CMOSSave.',13,10
               db        '$'
ParmIndex      dw        0
Filename       db        64 dup (0)     ; asciiz filename
SlashQuiet     db        0              ; -1 means quiet mode /Q
CMOSSize       db        0              ; size of cmos in bytes
CMOSBuff       db        128 dup(0)     ; buffer to hold CMOS contents.
;       Add to this list if you need more volatile bytes.
;       Remember the trailing h.
;       CmosRest Volatile bytes are not restored.  CmosChk volatile bytes are not checked.
;       0..0A are volatile
;       00ch is status byte
;       032h is century byte
;       038h is volatile why?
;       03Ah is Sony PNP BIOS bit
;       03Fh is Pentium volatile byte
;       040 to 042 are chip maker proprietary bytes.
;  CMOSCHK list, differs from CMSREST  list.
VolatileList   db        0ah,0ch,032h,038h,03Ah,03Fh,040h,041h,042h
VolatileCount  equ       $-VolatileList
data           ends
com            group     code,data      ; force data segment to go at the end
               assume    CS:com,DS:com,ES:com,SS:com
                                        ; seg regs cover everything
               org       100H           ; in Code segment
;==========================
_Start         proc      near
;       M A I N L I N E   R O U T I N E
               cld
               call      Parse          ; get filename and /Q from command line
               lea       dx,BannerMsg   ; display the banner if no /Q
               call      SayQ
               call      ReadCMOSFromFile ; read CMOS contents from file
               call      CalcCMOSSize   ; it is 64 or 128 bytes long?
               call      CompareCMOS    ; compare CMOS with buffer
               lea       dx,WorkedMsg   ; crow about success
               call      SayQ
Done:
               mov       ax,4c00h
               int       21h            ;normal termination
_Start         endp
;===============================================================
include        cmosinc0.asm
include        cmosinc1.asm
;===============================================================
CODE           ends                     ; end of code segment
               end       _Start