Here's some info about the flash recovery routines of the 2 most comomon BIOS brands: AMI and Award. You may need this guide if you've just messed up your BIOS but it's still kind of beeping, or giving other signs of life (in other words: if the Boot Block part of the BIOS is still working).AMIBIOS (American Megatrends, Inc.)
1. Copy a known working BIOS image for your board to a floppy and rename it to AMIBOOT.ROM
2. Insert the floppy in your system's floppydrive.
3. Power on the system while holding CTRL+Home
keys. Release the keys when you hear a beep and/or see the floppy light coming on.
4 . Just wait until you hear 4 beeps
. When 4 beeps are heard the reprogramming of the System Block BIOS went succesfull, so then you may restart your system.
Some alternative keys that can be used to force BIOS update (only the System Block will be updated so it's quite safe):CTRL+Home
= restore missing code into system block and clear CMOS when programming went ok.CTRL+Page Up
= restore missing code into system block and clear CMOS or DMI when programming went ok.CTRL+Page Down
= restore missing code into system block and do not clear CMOS and DMI area when programming went okBut what about that progress bar on the screen?
If your system has AMIBIOS8 based firmware you'll see a progress bar on the screen during the programming process.
It indicates the progress of the programming process.Award BIOS (Phoenix Technologies, Ltd. – Award Software International, Inc.)
1. Turn on the system and wait until you hear a beep and/or see the floppy light coming on (try hitting ENTER
-key if there isn’t any activity, in some cases this will help). In SOME cases you may see something on the screen but generally AGP VGA is disabled by the Award Boot Block BIOS.
2. Make a bootable DOS floppy
(so with IO.SYS, Command.com, etc.) with Awardflash
, a known working BIOS image
, and an AUTOEXEC.BAT file
with flashinstructions (example: “AWDFLASH BIOS.BIN /py /sb” - AWDFLASH is the name of the flasher, BIOS.BIN is the name of the BIOS file, /py /sb are optional commands; /py is the command for auto-flashing; /sb is the command for skipping Boot Block BIOS updation - Highly Recommended
to skip it!).
3. Insert the floppy in the floppydrive and wait. If the BIOS is succesfully reprogrammed the system will reboot automatically.Phoenix BIOS (Phoenix Technologies, Ltd.)
There seems to be no certain routine for the Phoenix BIOS Boot Block.
The only thing I can say is that it uses a kind of DOS prompt like the Award BIOS Boot Block uses.Usage of Boot Block BIOSThe Award BIOS Boot Block can be only used when it's activated due to a corrupted System Block checksum or a complete System Block mismatch.
The AMIBIOS Boot Block can be also used for normal BIOS update since it can be activated by pressing CTRL+Home keys during power on. Since this way only the System Block BIOS wil be updated (so the Boot Block BIOS remains unmodified) it is a very easy and quite safe alternative for using an external flasher such as AMINF or AMI Win Flash. If you update AMIBIOS this way, you'll be always able to recover a bad flash. Warning for ASRock mainboard users:
The AMIBOOT.ROM flash recovery method does NOT work with ASRock motherboards (ASRock uses AMIBIOS for all its boards). ASRock has taken the feature outof the Boot Block BIOS due to space limitations of NVRAM chip (a bad reason since you can just use a type of EPROM with a larger capacity).Note from ASRock TSD:
"The AMIBOOT.ROM method is disabled in ASRock BIOS. Due to the space limitation of EEPROM , we do not support this function. So far, there is no way to recover a bad flash on our mainboards."[/I]Hotflashing: (see also Bas' FAQ based on his own experiences about it: "BIOS recovery the dirty way")
You’ll need 2 motherboards which are using the same size EEPROM (better you use 2 exactly the same boards, since this has generally a better chance of success). But ok, now to hotflasing:
1. Pull out the working EEPROM and put it back CAREFULLY(!!! – So that it can be easily taken out when you’re at the DOS prompt).
2. Bootup the system to the DOS prompt.
3. Copy the program “Uniflash” and a known working BIOS image to a floppy and insert this floppy in the drive.
4. Now take out the working EEPROM CAREFULLY(!!!), and put in the misprogrammed EEPROM (push a bit until it’s properly seated into the socket, to prevent errors while flashing).
5. Flash the BIOS image into the misprogrammed EEPROM (including Boot Block, otherwise it won’t work)
6. If the flash went ok, turn off the system and put both chips back into their original mainboards. You should now have 2 working boards again. WARNING: Please be careful when you put in the EEPROM. When you insert it the wrong way the chip will be fried!