[LinuxBIOS] flashrom support for AMD CS5536

[Alan Alexander]

Hi all,

I've recently checked out and built revision 2977 of flashrom in order
to apply a simple BIOS configuration change to approx 200 embedded Linux
devices.
Unfortunately although flashrom is able to read the contents of the BIOS
flash, writes fail to take (verification fails).

The system basics are as follows:
    IEI NanoLX Board (AMD LX800 + CS5536 + Winbond W83627EHG)
http://www.ieiworld.com/en/product_IPC.asp?model=NANO-LX
    Linux Kernel Version 2.6.20
    Flash part identified by flashrom as Pm49FL004 at physical
address 0xfff80000 (512 KB)

I see from the source code that the CS5536 chipset is directly supported
and that the code attempts to remove the write protection via MSR
0x1808. This all looks good and yet the writes fail to take. I assume
therefore that this board is using some GPIOs to disable writes to the
BIOS flash?

Does it sound likely that GPIOs are causing the write problem that I am
seeing? Does anyone know how I might go about figuring out which GPIOs
to look at?

Any help would be very appreciated.

Best regards,

Alan Alexander          mailto:[e-mail]
Icera Inc, 2520 The Quadrant, Aztec west, Bristol BS32 4AQ, UK
Tel. [phone]