Xen devel - Sep 2013 - Re: [cros-discuss] Boot in Hyp mode on Samsung ARM Chromebook

> On 04/14/2013 03:23 AM, Anthony PERARD wrote: 
>>  On Sat, Apr 13, 2013 at 7:40 PM, Mike Frysinger
<vap...@chromium.org> wrote:
>>>  On Sat, Apr 13, 2013 at 1:41 PM, Chen Baozi
<chen...@gmail.com> wrote:
>>>>  Just one question about dom0''s command line. 
>>>>  
>>>>  The original CONFIG_CMDLINE from linux-chrome git repo is 
>>>  
>>>  don''t look too much (or at all) at the default value. 
it''s a
>>>  historical artifact and we don''t use it at all. 
>>  
>>  Exactly! 
>>  
>>  Under Xen, the command line given to dom0 is in the dts. Xen will look
>>  for "xen,dom0-bootargs" in the node "chosen". 
>>  The dts: arch/arm/boot/dts/cros5250-common.dtsi 
>> Thanks Mike & Anthony! 
> 
> I changed the xen,dom0-bootargs to "console=hvc0,115200n8 console=tty1
> debug root=/dev/mmcblk1p3 rw rootwait init=/bin/bash" in 
> arch/arm/boot/dts/cros5250-common.dtsi, and print the bootargs in 
> function write_properties in xen/arch/arm/domain_build.c:127. Then I 
> recompiled the dts & xen, ''dd'' the image signed and
bundled with dom0 &
> dtb to the boot partition and see whether we have passed the
"right"
> bootargs to dom0. After rebooting and checking the log in 
> dmesg-ramoops-0, I did read the line printed "console=hvc0,115200n8 
> console=tty1 debug root=/dev/mmcblk1p3 rw rootwait init=/bin/bash". 
> However, everything stays the same as before. 
Hello guys,

I''m trying to reproduce on my Chromebook the environment described by
Anthony and already reproduced by Chen. Unfortunately I don''t get any
message to dmesg-ramoops after reboot :(

My cross compile environment works, I''m able to recompile a fresh Linux
kernel and the 3.4 kernel boots without problems. Then I followed _exacly_ what
reported by Anthony on the wiki: I cloned the linux-chromebook kernel repo, the
xen-arm repo, switched to chromebook-2013-03-22. The dtsi is correct, image is
signed, dd to the usual partition etc etc. After reboot I don''t see
anything on the display and this is expected: unfortunately after rebooting into
either linux or chromeos I don''t see logs saved in dmesg-ramoops. I
also tried the patches to the kernel .config by Chen but with no success.

I''m wondering if the hardware could have been changed in the meanwhile:
Chen, would you mind please post somewhere the unsigned image that you used to
get those interesting dmesg-ramoops messages? so that I can try to see after
reboot if I''m getting something similar in /dev/pstore ?

My plan is to solder a serial cable to the motherboard uart that was recently
discovered and begin debugging but I would like to start exactly from the point
you already are.

Many thanks,
-Francesco