 Number 222 - November 2001 |
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| BIOS Recovery Guide | ||
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by Robert Richmond. July 2001 (mailto:RobRich999@excite.com)
via Simi Valley Computer User Group. August 2001 | ||
The Basic Input/Output System provides the roadmap to all computer
operations for each of the various subsystems. Most motherboard vendors
release BIOS updates on a regular basis, as each new version typically
offers improved performance, stability, or compatibility. While detailed
instructions are usually available for the upgrade procedures, the
chance for BIOS corruption is a readily understood risk. An improperly
coded BIOS file, a bad flash routine, a power failure, and a variety of
other problems can occur during the update.
Even after a failed flash, a potentially dead motherboard can possibly still be recovered. Most BIOS manufacturers (Award, Phoenix, and AMI) now include an option known as Boot Block protection. The Boot Block sector is write protected, thus it can only be damaged if the flash utility is explicitly directed by a command line switch to overwrite this EEPROM memory range. The Boot Block can load the most basic BIOS functions for the simple I/0 operation of ISA video, floppy drive transfers, and keyboard input. Luckily these features are all that is generally required to rebuild the entire working BIOS. Required Features Floppy Drive - Needed to load boot disk and new BIOS update Boot Floppy - Needed to load the basic operating system, preferably MS-DOS ISA Video Card - Optional, but can simplify the recovery process Each required aspect should be self-explanatory to most users. A startup disk can be automatically built from the Add/Remove Programs applet within the control panel. The boot disk is a vital part of this guide, though users with WinNT /2K will need to build this boot disk from a system running MS-DOS or Win9x/ME. If this is not possible, then a variety of DOS-oriented boot disks are available for download from BootDisk.com. Be sure to copy all needed BIOS utilities and update/backup files used during the original flash process to this disk as well. Video-enabled Recovery Assuming an ISA slot is available, then the least complex method for BIOS recovery is possible through the usage of a now outdated ISA video card. Remove all peripherals and devices except the ISA video, floppy, and keyboard. Now proceed to boot as normal from the startup floppy disk. Be sure to bypass any startup routines included with the disk by booting to just the standard safe-mode command prompt. Usually this can be accomplished by pressing CTRL or F8 during the boot process. |
Once at the comment
prompt, just follow the exact update procedure as outlined by the vendor
upgrade guide to restore the original working BIOS that was saved
during the faulty flash. If the backup is not available, then be sure to
download the latest specific BIOS update directly from the motherboard
manufacturer site.
Automatic Recovery Even if an ISA slot or video card is not available, then BIOS recovery is usually still a good possibility. To utilize this process, the startup disk must be edited to auto-load the BIOS flash utility at boot time. After using Windows to build the boot disk, it is recommended to delete or rename both the config.sys and autoexec.bat files found in the disk's primary directory path. This insures no additional programs are loaded which could interfere with the operation of the BIOS flash application. As with the previous technique, all BIOS files and utilities must be copied to the startup disk. A custom autoexec.bat file now must be created to load the BIOS utility at boot time. Using a raw text editor, such as Notepad, the proper BIOS utility command line must be entered as specified in the manufacturer BIOS upgrade process. Be sure to save the file with the proper .bat extension, not the .txt extension as often defined be most text editors. A sample entry for those using Award's FLASH utility with a BIOS file named "backup.bin" would resemble this: a:\awd802.exe backup.bin /py /Sb /sn /cc /cp /cd /R The above command forces a BIOS flash of "backup.bin", resets all configuration data to defaults, then reboots the system. Other command can be referenced by executing the command "awd802.exe /?" from the prompt. The approach for using flash utility from AMI or Phoenix is similar, but be sure to read the provided help information about each command line option before building the autoexec.bat entry. Create the text command entry, and then save to the file "autoexec.bat" in drive A:\. This will load the command at floppy boot time, regardless of whether an ISA video card is available. Conclusion Regardless of the process utilized, each of these techniques has saved countless thousands of dollars for many people. Trying to order BIOS chips can prove a tedious and nerve wrecking,1 plus replacing an entire motherboard can prove rather costly to say the least. I personally have recovered several boards through these techniques, and thus have lowered my hardware replacement overhead while increasing positive response for my clients due to minimal repair times. Hopefully this guide will prove equally valuable for others as well.
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Number 222 - November 2001
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