Section 3.4. Upgrading the System BIOS

3.4 Upgrading the System BIOS

When you upgrade an existing system without replacing the motherboard, the BIOS version it uses can be a critical issue. Some system features notably support for large hard disks, high-speed transfer modes, and AGP are BIOS-dependent, so an in-place upgrade often requires a BIOS upgrade as well. Fortunately, recent systems use a flash BIOS, which can be upgraded simply by downloading a later version of the BIOS to replace the existing BIOS.

Be extraordinarily careful when upgrading a flash BIOS. Before you proceed, make absolutely sure that the BIOS upgrade patch you are about to apply is the exact one required for the current BIOS. If you apply the wrong patch, you may render your system unbootable from the floppy drive, which makes it difficult or impossible to recover by reapplying the proper patch.

Upgrading a flash BIOS requires two files. The first is the upgraded BIOS itself in binary form. The second is the "flasher" program provided by the BIOS manufacturer, e.g., awdflash.exe. The exact steps you follow to upgrade a flash BIOS vary slightly according to the BIOS manufacturer and the version of the flasher program you are using, but the following steps are typical:

1. Before proceeding, record all current BIOS settings, either using pencil and paper or a utility program that writes BIOS settings to a disk file. If you have a UPS, connect the system to it for the duration of the BIOS update. Losing power during a BIOS update can result in a motherboard that is unusable and must be returned to the maker for repair.

2. Determine the manufacturer, version, date, and identifying string of the existing BIOS. You can do this by using a third-party diagnostics program like CheckIt, or by watching the BIOS screen that appears briefly each time the system boots. With most systems, pressing the Pause key halts the boot screen, allowing you to record the BIOS information at your leisure. With other systems, the Pause key does nothing, so you may have to reboot the system several times to record all the relevant information. It is important to record exactly what appears. Completely different BIOS versions are often differentiated by very minor changes in the BIOS identifying string.

3. Locate a flash BIOS patch file that is intended to upgrade the exact BIOS version you have. Close isn't good enough. Begin your search on the PC manufacturer's web site. If you can't find an appropriate BIOS update there, check Wim's BIOSPage at http://www.wimbios.com. While you are searching for the proper BIOS update file, keep the following points in mind:

   • Having a particular PC model is no guarantee that it uses the same BIOS as another PC with the same model number. High-volume PC manufacturers often sell systems that use different motherboards under the same model designation, and the BIOS update file intended for one motherboard used in that model cannot be used to upgrade the same model with a different motherboard.

   • A particular motherboard and BIOS may be available in several versions that cannot use the same flash update file. For example, Micron produced several systems using the popular Intel SE440BX Seattle motherboard, but with a slightly customized BIOS. The SE440BX flash update available on the Intel web site can be used to update only an unaltered SE440BX, not the Micron version of that motherboard.

   • Even a motherboard supplied directly by the manufacturer may have shipped in several revisions that require different BIOS patches. For example, one of our systems uses an EPoX KP6-BS dual-CPU motherboard, which was made in two versions, one with a 1 MB BIOS chip and the other with a 2 MB BIOS chip. The BIOS patches for these two versions are different and incompatible. Sometimes the only way to know for sure which BIOS patch you need is to literally take off the cover and examine the identifying numbers on the flash BIOS chips themselves.

   • BIOS patches are cumulative. That is, if your existing BIOS is version 4.003, you may find that the web site has versions 4.004, 4.005, and 4.006 available. You need not apply each of those patches sequentially. Instead, update your 4.003 BIOS directly to 4.006 in one step by applying the 4.006 patch to it.

   • BIOS patch files are usually supplied in .bin, .exe, or .zip form. The .bin files can be used directly by the flasher utility. When run, the .exe files automatically extract the BIOS patch in .bin form. If the BIOS update is supplied as a .zip file, use WinZip or a similar zip utility to extract the .bin file.

4. Download the BIOS flasher utility, either from the motherboard manufacturer's web site or directly from the BIOS manufacturer's web site. Note that some motherboard manufacturers supply BIOS updates as an archive file (.zip or .exe) that contains both the BIOS update .bin file and the flasher utility. These distributions sometimes take the form of an executable file that when run automatically creates a bootable floppy diskette and copies the .bin BIOS update file and the flasher utility to it.

5. Unless the BIOS update you've downloaded is one of those that automatically creates a boot floppy, format a bootable floppy disk. If you are using MS-DOS, Windows 3.X, or Windows 9X, use the command format a: /s to create the bootable floppy. If you are updating the BIOS on a system that runs Windows NT, Linux, or another non-DOS operating system, format a bootable DOS floppy on another computer. Copy the flasher utility and the .bin file to this floppy.

6. Enable flash BIOS update mode on your motherboard. To prevent viruses from altering the system BIOS, most motherboards have a jumper that must be set in one position to enable flash BIOS updates and in another position to re-enable normal system operation. Set this jumper to BIOS update mode.

7. Boot the system using the DOS boot floppy you created earlier. At the DOS prompt, type the command line specified in the documentation for your flasher utility. For example, the command to update an Abit BH-6 motherboard using the Award flasher and the bh6_gy.bin BIOS update file while saving a copy of the old BIOS and clearing the CMOS settings is Awdflash bh6_gy.bin Oldbios.bin /cc. The Oldbios.bin specifies the filename that the old BIOS will be saved as, and the /cc argument clears CMOS settings.

8. When the flash BIOS update completes, restart the system and enter BIOS setup mode. Depending on the BIOS manufacturer, the flasher version you use, and the command-line arguments you specified, the CMOS settings may or may not be cleared. Even if they aren't, it's always a good idea to clear and re-enter them after a flash BIOS update, and for many BIOS updates it's mandatory. To do so, load the default BIOS settings and then enter the correct settings for time and date, hard disk type, etc., that you recorded in Step 1. Once you have entered the correct settings for all values, restart the system again. It should display the updated BIOS version in the boot screen.

Although most recent systems use some variant of the method described above, some systems allow you to update the BIOS simply by copying a .bin file to a floppy diskette, which needn't be bootable, and restarting the system with that floppy in the drive. The obvious danger with this method is that you might unintentionally update your BIOS from a floppy disk that contains an older or hacked version. Accordingly, most recent systems require you to explicitly move a jumper to enable BIOS update mode.

Although updating a flash BIOS is a pretty intimidating operation the first time you try it or the tenth time, for that matter BIOS updates usually complete successfully if you do everything by the numbers. But if you accidentally apply the wrong patch or if the flash update process fails through no error of your own, the PC can end up unbootable. If this happens, there may not be an easy way to recover. Depending on the BIOS, one of the following methods to recover from a failed flash BIOS update may be usable:

• A few motherboards have dual BIOS chips. If you corrupt one BIOS during an update, you can boot the system from the other BIOS and reflash the corrupted BIOS.

• Recent Award BIOSes have a small permanent boot-block BIOS. This portion of the BIOS is not overwritten during a flash update, and is sufficient to allow the computer to boot to a floppy disk. Unfortunately, this BIOS supports only the floppy disk and an ISA video card. If a flash update fails on a system with such a BIOS and a PCI or AGP video card, you can reflash the BIOS by using another system to create a bootable floppy disk that contains the awdflash.exe utility and the proper BIOS .bin file, with an Autoexec.bat file that automatically executes the flasher utility with the proper command-line arguments. With a PCI video card, you will not be able to view the progress of the update, but once the update completes and you restart the system, everything should operate properly. With an ISA video card, you can view the update procedure as it occurs.

• The flash BIOS chip on some systems is socketed rather than soldered. If a failed flash BIOS update renders such a system unbootable, you can contact the system manufacturer to request a working BIOS chip. Most manufacturers will supply a replacement chip that contains the current version of the BIOS on request. Some even do so for no charge, although they often require that you return the original nonfunctional BIOS chip. If you can get a replacement BIOS chip, simply pull the original chip, replace it with the new chip, and restart the system.

• As a last resort, if you have an identical system that works, you can temporarily install the BIOS chip from the good system into the non-working one and reboot that system using the good BIOS chip. Once the system boots, pull the good BIOS chip and replace it with the non-working BIOS chip without powering down the system. Then, with the system still running, execute the flasher utility from diskette to reapply the flash BIOS update to the damaged BIOS chip. As a general rule, of course, removing and installing chips while the system is running is a good way to fry a motherboard. We've never tried this and can't guarantee that you won't fry your motherboard if you try it, but some people claim to have done it successfully. If you try it, do so at your own risk.

Because a failed flash BIOS update may have such dire results, never flash a BIOS without first connecting the system to a UPS, if only temporarily while doing the update. The one time we violated that rule, sure enough, the lights flickered about five seconds after we started the update. Hoping against hope that the PC hadn't crashed this update was one of those ones where the screen stays blank until the update is complete we sat staring at the blank screen for another half hour before we admitted to ourselves that we'd probably just killed the motherboard. With our fingers crossed, we powered the system down and back up again, but, as expected, it was deader than King Tut. Unless your luck is better than ours, always use a UPS when flashing a BIOS.