Hi Nico,
thanks for the quick feedback!
Well, if you haven't already, try a lower speed? 70MHz is pretty high, too high for your setup. The answer flashrom gets to the RDID command "e1 908c" is close to the expect ids "c2 2018" if you shift it to the left.
Okay, that seems to make sense. I tried it with lower speeds, but flashrom did not detect any chip than, so I thought it is not working.
Even if it seems to work less with a lower speed, please send logs for that too (e.g. spispeed=30000, 10000, 1000).
You find the logs attached. The lowest speed flashrom outputs "chip found" is at 31250 kHz.
Fabian