[flashrom] Image size doesn't match the flash chip's size

[Stefan Tauner]

On Sun, 22 Nov 2015 20:46:21 +1000
Adam Nielsen <a.nielsen at shikadi.net> wrote:

> > Don't use the force switch. It's the dark force :P
> 
> Well on that note, I also wanted to dump some AT27C010 chips, which are
> one-time programmable, but electrically compatible for read operations
> with "standard" chips like the AT29C010A.
> 
> I couldn't dump anything because flashrom told me no EEPROM was
> detected.  By using --force and specifying AT29C010A I was warned I
> would probably get garbage, but the chip content was successfully
> written to a file.

That's about the only situation where the force switch does the right
thing :)

> Are there plans to add read-only support to flashrom for these cases?
> I am guessing this would be (relatively) easy because to my knowledge,
> you don't need special commands to read data out of the chips.  They are
> all just read in the same way (at least with the nic3com and nicrealtek
> programmers).  I imagine you'd just need a handful of generic devices
> that specify the size of the chip and only support read operations?

flashrom works by probing for the chip ID and looking for that in its
database for the details like capacity and block sizes. EEPROMs do not
support any ID commands so that scheme cannot work. Specifying all the
details via the command line is not really a good idea. However,
specifying generic devices could indeed be an option - in the long term.

> 
> I've attached the log because it said the AT29C010A was untested.

I would need to dig into that a bit, because the write error you saw
could actually come from a not perfectly matching write function... the
code has a fixme comment I don't know about.
Unfortunately, I won't have time for that today, but I'll put it on my
todo list.
-- 
Kind regards/Mit freundlichen Grüßen, Stefan Tauner