[flashrom] Flashing ThinkPad X200 (was: Problems with CH341A)

[Nico Huber]

Hi Potato,

On 07.06.2016 18:59, potato wrote:
> I know that the programmer works, since I was able to make goods dumps
> of a MX25L8006 that was on a old router, but I was not able to detect a
> MX25L6405D that was on my Thinkpad X200 (it could not even find a chip).
> I know it is not a problem with the SOIC16 clip that I used since I was
> able to use it on a rayer_spi device.
The problem is not the flash chip itself but the circuitry surrounding
it. Every device that you flash by ISP is a different story, especially
when the device is not meant to be flashed by ISP. The X200 is one of
those and particularly hard to flash. Presumably because of some capa-
city on the CS line. So you need a programmer that can drive CS pretty
strong, or work around by using a very low SPI clock or hack flashrom
to assert CS earlier (that works for me using a FT2232H based program-
mer). I've seen a Raspberry Pi 2 programming an X200 oob, supposedly it
drives CS strong enough.

Here's a clumsy patch for flashrom that might help:
http://paste.flashrom.org/view.php?id=2802
It adds dummy reads that might kind of pre-charge CS.

Urja, do you know a way to assert CS earlier on a CH341A?

> Sorry if I caused any problems, Potato
No problems.

Nico