[flashrom] FYI: flashrom output for Altera EPCQ16

[Ma, Peter]

Hi, Stafan...

I am not sure what the relationship between Altera and Micron, but it would not surprise me.  Whatever the case, it pre-dates the Intel acquisition.

> Have you tried what flashrom promises...
I started to just after I sent that e-mail to you.  But it appears flashrom only allows files the same size as the Flash device.  I searched and found some old flashrom forum discussions about that.  I understand the not wanting to allow casual users to not accidentally mis-program their BIOS.  But it does make flashrom not very useful for non-BIOS uses -- like programming FPGA bitstreams, etc.

Regards,
---------------------------------------------------------
Peter Ma                 | email: peter.ma at intel.com
Senior Design Engineer   | tel: +1 (604) 742 5778
Intel of Canada, Ltd.    | fax: +1 (604) 639 1185
#688 – 1333 West Broadway, Vancouver, BC, Canada, V6H 4C1


-----Original Message-----
From: Stefan Tauner [mailto:stefan.tauner at alumni.tuwien.ac.at] 
Sent: Wednesday, June 29, 2016 11:47 PM
To: Ma, Peter <peter.ma at intel.com>
Cc: flashrom at flashrom.org
Subject: Re: [flashrom] FYI: flashrom output for Altera EPCQ16

On Thu, 30 Jun 2016 00:53:28 +0000
"Ma, Peter" <peter.ma at intel.com> wrote:

> https://www.altera.com/content/dam/altera-www/global/en_US/pdfs/litera
> ture/hb/cfg/cfg_cf52012.pdf
> 
> […]
> 
> Probing for AMIC A25L05PT, 64 kB: probe_spi_rdid_generic: id1 0x20, 
> id2 0xba15

Hello Peter,

thanks for your report. The replies this chip sends makes me think that Altera acquired the IP from Micron because the ID is exactly what you would expect from an N25Q016??3E chip, that is a 3.3 V, 16 Mb flash chip. However, as far as I can tell there never was a public datasheet available for such a chip, only its 1.8 V variants (which are supported by flashrom). The IP theory also makes completely sense due to the bonds (no pun intended) between Intel and Micron as well as Intel and Altera ;)

The Altera datasheet disguises this by specifying the replies to the RDID identification opcode (Read Device Identification Operation)
incompletely: they do not define the first and second byte of the reply. The first byte identifies the flash as ST (now Micron): 0x20.

I'll need to dig further to see if there are any clear distinctions between the "Altera" chips and the existing bigger 3.3 V ST models that are also specified in the Altera datasheet but for which I have original Micron datasheets to cross check. If nothing dramatically comes up I'll add the needed chip definition to flashrom. Have you tried what flashrom promises, i.e. that flashrom should fully work with the generic definitions replied by the chip (SFDP)?

--
Kind regards/Mit freundlichen Grüßen, Stefan Tauner