[coreboot] [flashrom] unusual SST39SF020 chip

Carl-Daniel Hailfinger c-d.hailfinger.devel.2006 at gmx.net
Thu May 15 04:32:13 CEST 2008

Hi Andriy,

On 14.05.2008 22:30, Andriy Gapon wrote:
> First of all, I have a very rough (and ugly!) patch that makes flashrom 
> work on FreeBSD. I tried it for reading BIOS image and it worked.

Can you mail the patch to the list? We want flashrom to be
cross-platform and will try to merge the patch or at least a variant of it.

> I have an old system with MP2-BX-X, please see some description here:
> http://www.geocities.com/SiliconValley/3686/delta_mp2.html
> It is based on 440BX chipset.
> Visually I was able to identify that BIOS flash chip is SST39SF020, but 
> flashrom didn't initially recognize it.
> Some debugging showed that it has JEDEC ids 0x25 for vendor and 0xE5 for 
> device. Very unusual. So I decided to let you know.

The JEDEC vendor ID 0x25 can mean any of the following companies:
- Tristar
- Zarlink/Mitel
- Chameleon systems
- Kingmax Semiconductor
- Phyworks
- Power-One

None of the companies above are in the BIOS flash market AFAICS.
Probably this is just a strange reading of real flash contents at ID

> The data that flashrom read are very similar to the data in vendor 
> provided bios .bin. There are differences in a chunk of about 12k size, 
> I guess this is where bios stored some config data.

Can you hexdump the first 8 bytes of the bios.bin you read back from
your chip?


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