[flashrom] Erase Fails on Winmate I370 Motherboard with PMC Pm49FL004 Flash Chip

[Stefan Tauner]

On Mon, 10 Dec 2012 14:35:54 -0500
sdbarnes at rockwellcollins.com wrote:

> I think I have verified that there is no issue with flashrom 0.9.3 and the 
> PMC Pm49FL004 chip.
> 
> I had received some Pm49FL004 chips from a vendor with a WinMate I330 BIOS 
> load (an I330 message was being displayed briefly on BIOS POST). Am I 
> correct in assuming that some portion of the BIOS (e.g.,boot block) cannot 
> be updated with flashrom? 

that depends on how the boot block (or any other range) is protected,
there are various schemes to do this. the most common one is to use a
dedicated write protection pin for the whole device or the boot block
(or both), which can be changed by a GPIO of the southbridge or super
i/o chip (flashrom supports a huge number of mainboards that need
this, but each had to be added manually). but there are also some flash
chips that can be locked by software which is done by the BIOS before
the OS even loads (and there are various other schemes involving the
chipset).

the log you provided indicated that *if at all* there were only bits
changed from 0 to 1 (by erasing whole blocks). this may have been
because you rerun flashrom to obtain the log and the actual changes
were done in an earlier run. flashrom would then skip every block that
is already equal...

> I never saw a checksum error after rebooting my 
> motherboard and I know that my BIOS defaults had been updated from the 
> factory defaults.
> 
> I have since received some more Pm49FL004 chips from the same vendor with 
> a WinMate I370 BIOS load and flashing these chips with a different I370 
> image works with flashrom-0.9.3 without any issues.

this would OTOH indicate that there is no (hardware) write protection
in place... i so am a bit puzzled ATM about what's the real issue (if
there is any) and what happened exactly.
-- 
Kind regards/Mit freundlichen Grüßen, Stefan Tauner