[flashrom] serprog with arduino UNO

[Denis 'GNUtoo' Carikli]

Hi,

On Fri, 19 Jul 2013 12:01:52 -0300
Hugo Petrucci <hugopetrucci at hotmail.com> wrote:

> hugo at hugo-linux ~/flashrom $ sudo ./flashrom -c "SST25LF040A" -V -p
> serprog:dev=/dev/ttyACM0:2000000
I still have to fix the speed issue on the arduino uno:

On the Arduino UNO there is an Atmega328, which runs the code someone
usually flash on his Arduino(here it runs the serduino code).
But there is also another microcontroller: an Atmega8U2 or
Atmega16U2(depending on the Arduino UNO revision), which is used to do
the USB<->Serial conversion.
That conversion is done in software, and uses a library called LUFA.
On the Arduino UNO, if someone uses speeds that are too high, there is
a huge probability that the communication will stall between flashrom
and the Atmega328.
According to the LUFA developers, it's because the code in that
Atmega8U2/Atmega16U2 was not meant to handle such high speeds...

So it works way better by lowering the speed in the serduino code and
ajusting the speed parameter in the flashrom arguments.

Since I relocated, and I don't have my Arduinos with me, I'll have to
wait to get access to them again, and try to solve that problem and
also respond to LUFA developers...

Still if you are able to test new code, I could do some code
adaptations, push in a test branch, then you would test, and then I
would push in the main branches.

Denis.