[LinuxBIOS] flashrom support for AMD CS5536

Alan Alexander alan at IceraSemi.com
Fri Nov 23 12:23:32 CET 2007

Thanks for the information. The patch certainly seems to have cured that
problem. Unfortunately, although I can now write to the Flash (and
verify the contents) it seems that the image is over-written when the
board reboots (i.e. the BIOS change doesn't take effect and a subsequent
verification of the previously verified image fails).

Presumably there's a shadow copy left unmodified somewhere? 

Any ideas?

Best regards,

Alan Alexander          mailto:alan at icerasemi.com
Software Toolchain Engineering
Icera Inc, 2520 The Quadrant, Aztec west, Bristol BS32 4AQ, UK
Tel. +44 (0)1454 284805 
-----Original Message-----
From: linuxbios-bounces+alan=icerasemi.com at linuxbios.org
[mailto:linuxbios-bounces+alan=icerasemi.com at linuxbios.org] On Behalf Of
Nikolay Petukhov
Sent: 23 November 2007 07:06
To: linuxbios at linuxbios.org
Subject: Re: [LinuxBIOS] flashrom support for AMD CS5536

2007/11/22, "Alan Alexander" <alan at IceraSemi.com>:
> 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
> devices.
> Unfortunately although flashrom is able to read the contents of the
> 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
> 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
> 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:alan at icerasemi.com
> Icera Inc, 2520 The Quadrant, Aztec west, Bristol BS32 4AQ, UK
> Tel. +44 (0)1454 284805

I have the same problems with flashrom on iei/pcisa-lx.
http://www.ieiworld.com/en/product_IPC.asp?model=PCISA-LX (Flash

Info from pm49fl002/4's manual: Pm49fl002/4 write protected at power up.
This patch fix it.


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