Can a motherboard BIOS be unbricked?

[Jimjamesjimothy8]

I'm just curious, I don't actually have a bricked mobo. I have a Gigabyte dual bios motherboard. If the main bios gets bricked, does the backup bios permanently become the new main bios? Or does the second bios restore the main one?

[Master Disaster]

Second bios reflashes the first one.

 

Also yes, it's possible to pull the BIOS ROM off the board and flash it using an external eeprom flasher. Difficult but possible.

[KarathKasun]

They flash alternately AFAIK.  You start on BIOS 0, when you update it the system flashes BIOS 1 and sets it to active.  When you update again it swaps to BIOS 0 again.  If you botch a flash, the next flash overwrites the botched chip and attempts booting from it.  In this way, you can never brick the board without trying pretty hard.

 

Some of their boards have a physical switch.  If you botch a flash, you boot off of one, flip the switch with the system on, and flash the BIOS again.

[Master Disaster]

Just now, KarathKasun said:

They flash alternately AFAIK.  You start on BIOS 0, when you update it the system flashes BIOS 1 and sets it to active.  When you update again it swaps to BIOS 0 again.

Nah, when you update it will update BIOS 1 then if it boots successfully it will flash BIOS 2, if it fails to boot then BIOS 2 is used to restore BIOS 1.

[KarathKasun]

1 minute ago, Master Disaster said:

Nah, when you update it will update BIOS 1 then if it boots successfully it will flash BIOS 2, if it fails to boot then BIOS 2 is used to restore BIOS 1.

Not on the older GB boards I have had, or the ASUS Maximus I have.  Doing a random flash on boot is more dangerous than just swapping back and forth.

[Levent]

16 minutes ago, KarathKasun said:

They flash alternately AFAIK.  You start on BIOS 0, when you update it the system flashes BIOS 1 and sets it to active.  When you update again it swaps to BIOS 0 again.  If you botch a flash, the next flash overwrites the botched chip and attempts booting from it.  In this way, you can never brick the board without trying pretty hard.

 

Some of their boards have a physical switch.  If you botch a flash, you boot off of one, flip the switch with the system on, and flash the BIOS again.

AFAIK, second bios on GB boards never actually gets updated (atleast that was the case in my Z77 boards both in UD5X and DS3H) every time first bios got corrupted second one was cloned in to first one.

[Falkentyne]

2 hours ago, KarathKasun said:

They flash alternately AFAIK.  You start on BIOS 0, when you update it the system flashes BIOS 1 and sets it to active.  When you update again it swaps to BIOS 0 again.  If you botch a flash, the next flash overwrites the botched chip and attempts booting from it.  In this way, you can never brick the board without trying pretty hard.

 

Some of their boards have a physical switch.  If you botch a flash, you boot off of one, flip the switch with the system on, and flash the BIOS again.

This doesn't work on Gigabyte boards.  This works when powered off, but the currently active bios will not switch when the power is already on--at least not using Qflash.  I have not tested if it works in MS DOS/command prompt mode with EFIflash booting from USB however.

[KarathKasun]

6 hours ago, Falkentyne said:

This doesn't work on Gigabyte boards.  This works when powered off, but the currently active bios will not switch when the power is already on--at least not using Qflash.  I have not tested if it works in MS DOS/command prompt mode with EFIflash booting from USB however.

This was the method bacak in like... Socket A days.  Like I said, i have some stupidly old stuff.  This is also how you recover dual bios GPUs.  The BIOS flash memory is inactive with the system booted into the OS, and if there is a physical switch on the board it just switches the enable signal from one chip to the other.