are all the Micron SPI parts mis-identified?

[WilliamLeara]

I recently submitted PR #382 with the intention of adding a new 128Mb SPI part.

After further review, it seems there may be a fundamental problem with the Micron section of descriptor.cpp. Micron's vendor ID is assumed in the code to be 0x20, but I believe it is actually 0x2C. Vendor ID 0x20 is XMC (Xinxin Semiconductor Manufacturing), a competitor SPI part vendor.

If you look at JEDEC's JEP106BH STANDARD MANUFACTURERS IDENTIFICATION CODE spec, it says Micron Technology is 0x2C, and XMC is 0x20: https://www.jedec.org/standards-documents/docs/jep-106ab

Going back to 2016 and SHA# cb43045 is looks like the Micron section was added assuming 0x20. My hunch is that we need to change the vendor IDs of all the parts that begin with M/N/MT to 0x2C, and the parts that begin with XM to stay at 0x20, but put them into a new section of the file dedicated to XMC.

Any comment? Does anyone have more background than me on this section of the code?

[WilliamLeara]

Update: did some investigation with a Dediprog ROM burner. According to Dediprog's database:

and

So it appears that all the vendor and device IDs in descriptor.cpp are correct, but that Micron and XMC share vendor ID code 0x20? I don't get that, but my hunch now is that we need to break out the parts beginning with "XM" to a new section dedicated to XMC. Besides that, the IDs appear to be correct.

Let me know if this plan sounds okay to you, @NikolajSchlej.

[NikolajSchlej]

Sure, go ahead. Those JEDEC IDs are a mess, and most of them are obtained from various sources of questionable quality, so any improvements there are greatly appreciated.
Flashrom project had been a very solid source of them over the years.

[NikolajSchlej]

#define ST_ID 0x20 /* ST / SGS/Thomson / Numonyx / XMC(later acquired by Micron) */
Good luck. :)

[NikolajSchlej]

I'm closing this one because the answer to the original question is clearly "no, they are identified correctly, because Micron is now owning XMC, so calling those parts Micron makes sense".