[LinuxBIOS] [Fwd: Hardware Write-Protect for BIOS & EC]

Bari Ari bari at onelabs.com
Fri Mar 24 22:52:27 CET 2006


Picking a flash device with a boot block that cannot be rewritten just 
via any possible software routine alone and only by being combined with 
hardware intervention will work.

The parts that require a higher programming voltage that Richard 
mentions is one good possible way.

This would also recover a damaged BIOS attacked by even phishers.

If the flash update was somehow corrupted via power interruption, 
infected BIOS update with a good checksum, etc. the boot section would 
still have an good booter.

-Bari

Richard Smith wrote:
>>
>>I think that having a 'you can never write this' bios image would be
>>useful. The power fail scenario is a concern.
>>
> 
> 
> Many flash parts support a hardware lock where you can set a split. 
> Areas that have been hardware locked can only be reprogrammed via the
> right programming voltage which is normally much higher than Vcc.
> 
> --
> Richard A. Smith




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