[coreboot] Chromebox debugging.

Kyösti Mälkki kyosti.malkki at gmail.com
Fri Jan 31 12:44:09 CET 2014

On 01/31/2014 11:03 AM, Timothy Potter wrote:
> Hi Kyosti,
>     Sorry, I reread your first reply and it became clear what you meant when
> looking on the Chomebox's /var/log directory.  I found the port at the back
> corner of the Chromebox is numbered  2-1.2.  None of the external ports
> connect as 1-1.2.  Connecting the phone with the EHCI debug device enabled
> kernel to the 2-1.2 port and booting Ubuntu on the Chromebox I see the
> following in kmesg:
> [    2.008799] usb 2-1.2: new high-speed USB device number 3 using ehci_hcd

Assuming usb 2 is PCI 0:1d.0 (which would have been clearly identified 
in parts of the log you did not send), use USBDEBUG_HCD_INDEX=1 for 
coreboot build.

Default kernel configuration will not output anything on usbdebug. Now 
that you know the correct physical USB port, have the phone powered on 
and connected, run 'cat /dev/ttyGS0' and then boot the chromebox with 
the coreboot image with usbdebug feature enabled.

On this boot, what do you get for dmesg output on the phone side? Just 
send the complete log or put it available for download without separate 

If still nothing interesting appears, you could try coreboot with 
spkmodem console and possibly POST display card, but I do not know how 
to connect those on chromebox.

And.. last but not least, the instructions you followed, did they have a 
step with 'make crossgcc'?


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