[LinuxBIOS] How to ID flash chip type from software?

Ronald G Minnich rminnich at lanl.gov
Sun Feb 26 21:15:52 CET 2006


Anton Boriso
> Calibrating timer since microsleep sucks ... takes a second
> Setting up microsecond timing loop
> 788M loops per second
> OK, calibrated, now do the deed
> Trying Am29F040B, 512 KB
> probe_29f040b: id1 0xff, id2 0xff
> Trying At29C040A, 512 KB

so it's almost certainly not a 512KB, since you are reading 0xff

> probe_jedec: id1 0xff, id2 0xff
> Trying Mx29f002, 256 KB
> probe_29f002: id1 0xdf, id2 0x24

0xdf, 0x24

now you could try dumping the bios without flashrom. if the first two 
bytes are not df,24 then you are probably doing an ID cycle, and 
flashrom just doesn't know this ID.

If the bytes ARE df,24, then write protection may be in effect.
> Trying SST29EE020A, 256 KB
> probe_jedec: id1 0xdf, id2 0x24
> Trying SST28SF040A, 512 KB
> probe_28sf040: id1 0xff, id2 0xff
> Trying SST39SF020A, 256 KB
> probe_jedec: id1 0xdf, id2 0x24
> Trying SST39VF020, 256 KB
> probe_jedec: id1 0xdf, id2 0x24
> Trying SST49LF040, 512 KB
> probe_jedec: id1 0xff, id2 0xff
> Trying SST49LF080A, 1024 KB
> probe_jedec: id1 0xff, id2 0xff
> Trying SST49LF002A/B, 256 KB
> probe_jedec: id1 0xdf, id2 0x24
> Trying SST49LF003A/B, 384 KB
> probe_jedec: id1 0x47, id2 0x97

interesting.
based on this, I'm guessing a 256kB part. Let us know if you can get the #.

ron




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