Re: [LinuxBIOS] flashrom support for AMD CS5536

[Alan Alexander]

My mistake - that patch hasn't made a difference to the behaviour.

It looks to me as if I'm unable to write to the top-block of the
Pm49FL004 device. Looking at the data sheet it appears that this device
has 2 write-protect pins - WP# (which looks as if it's wired up to the
AMD C5536 appropriately - such that writes to MSR 0x1808 have an effect)
and TBL# (Top-Block-Lock) which enables hardware write protection of the
top boot block (64Kbytes). Unfortunately I don't know how the TBL# pin
is connected to the CS5536. I'm guessing a GPIO.

Does anyone have any experience of using this BIOS flash with the
CS5536?

Many thanks,

Alan

Alan Alexander          mailto:[e-mail]
Software Toolchain Engineering
Icera Inc, 2520 The Quadrant, Aztec west, Bristol BS32 4AQ, UK
Tel. [phone] 
-----Original Message-----
From: linuxbios-bounces+alan=[e-mail]
[mailto:linuxbios-bounces+alan=[e-mail]] On Behalf Of
Alan Alexander
Sent: 23 November 2007 11:24
To: Nikolay Petukhov; [e-mail]
Subject: Re: [LinuxBIOS] flashrom support for AMD CS5536

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:[e-mail]
Software Toolchain Engineering
Icera Inc, 2520 The Quadrant, Aztec west, Bristol BS32 4AQ, UK
Tel. [phone] 
-----Original Message-----
From: linuxbios-bounces+alan=[e-mail]
[mailto:linuxbios-bounces+alan=[e-mail]] On Behalf Of
Nikolay Petukhov
Sent: 23 November 2007 07:06
To: [e-mail]
Subject: Re: [LinuxBIOS] flashrom support for AMD CS5536

2007/11/22, "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]

I have the same problems with flashrom on iei/pcisa-lx.
http://www.ieiworld.com/en/product_IPC.asp?model=PCISA-LX (Flash
Pm49FL004)

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