[LinuxBIOS] id1 & id2 - not chip ids

Peter Stuge stuge-linuxbios at cdy.org
Mon Apr 2 02:56:35 CEST 2007

On Sun, Apr 01, 2007 at 10:53:36PM +0400, Anton wrote:
> flashrom seems to work on ICH6 (and obviously on ICH7 in my
> previous post), despite the fact that BIOS_CNTL register isn't
> correctly set

Sorry, no.

> "Enabling flash write on ICH6-M...tried to set 0xdc to 0x3 on
> ICH6-M failed (WARNING ONLY)"
> Unfortunately, I can't say for sure which flashchip is hidden
> inside board (no data, this's from laptop) - but when
> Trying Am29F040B, 512 KB
> probe_29f040b: id1 0x55, id2 0xaa
> Trying Am29LV040B, 512 KB
> probe_29f040b: id1 0x55, id2 0xaa
> id1 & id2 are first bytes of original BIOS. What if change
> probe_29f040b() onto jedec_probe()?
> Will it give me correct chip IDs?

No. This means that the write enable operation failed and that no
writes are ever sent to the chip.

In order to identify the chip, writes to the chip must be working.

(Reading the chip ID requires a special sequence of writes and
finally two byte reads from address 0 and 1 for the vendor and
product ids. If the writes fail, these two bytes will contain
actual data.)


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