Question about status of coreboot on the Samsung XE303CE ARM Chromebook (snow)

[James MacMahon]

      Hi everyone,

Quick question: what is the status of coreboot + some payload being used with 
the Samsung XE303CE ARM Chromebook (snow)?

The page at [http://www.coreboot.org/Chromebooks] says 'Snow has das U-Boot 
nativly installed, but a coreboot port is available.', and the page at 
[http://www.coreboot.org/Supported_Motherboards] has 'Google Snow - Samsung 
Exynos 5250' under the 'Motherboards supported in coreboot', but I haven't
been 
able to find any blog / example of anyone actually flashing coreboot + some 
payload and booting their Chromebook like a regular computer.

It seems like there is a port available but no one has tried it from start to 
finish on the ARM Chromebook (where my definition of finish in this context is 
'booting with coreboot to stock Debian Linux', for example). I'm very keen on

doing this myself, and was hoping to find some example that I could read through
or even follow. This whole process of flashing a new BIOS is very new to me, and
I'm wary because of the potential to easily brick my device (however I'm not 
scared off by reflashing or external chip programming if it comes to it, I'd 
just like to avoid it).

Thanks for your time,
James

[David Hendricks]

      On Thu, Jan 30, 2014 at 9:53 AM, James MacMahon <jwm(a)operand.ca> wrote:

  Hi everyone,

 Quick question: what is the status of coreboot + some payload being used
 with
 the Samsung XE303CE ARM Chromebook (snow)?

 The page at [http://www.coreboot.org/Chromebooks] says 'Snow has das
 U-Boot
 nativly installed, but a coreboot port is available.', and the page at
 [http://www.coreboot.org/Supported_Motherboards] has 'Google Snow -
 Samsung
 Exynos 5250' under the 'Motherboards supported in coreboot', but I
haven't
 been
 able to find any blog / example of anyone actually flashing coreboot + some
 payload and booting their Chromebook like a regular computer.
Right now it's close, but not quite close enough to be useful. The coreboot
code should work, however there are some missing pieces that make it
difficult to use in a meaningful manner:

- We don't have a generic payload to use with coreboot on this platform.
The earlier work was done using Depthcharge which is a small payload
specific for booting ChromeOS (with its verified boot mechanism and such).
There is some (unfinished?) work to port FILO over, but I don't know what
the status is. You could also try using a Linux kernel as a payload, but
that has yet to be tried on this particular platform.

- To get serial console output, you need a debug board for Chromebooks
which is unfortunately not easy to come by. Due to this limitation, if you
are really intent on doing coreboot development on ARM it might be better
to start with a more readily hackable platform such as the Cubieboard or
Beaglebone.

It seems like there is a port available but no one has tried it from start
  to
 finish on the ARM Chromebook (where my definition of finish in this
 context is
 'booting with coreboot to stock Debian Linux', for example). I'm very keen
 on
 doing this myself, and was hoping to find some example that I could read
 through
 or even follow. This whole process of flashing a new BIOS is very new to
 me, and
 I'm wary because of the potential to easily brick my device (however I'm
 not
 scared off by reflashing or external chip programming if it comes to it,
 I'd
 just like to avoid it).
There are a few wiki pages out there which detail the steps necessary to
boot Debian/Ubuntu with the U-Boot firmware that ships with the device.
Here is one from debian.org:
https://wiki.debian.org/InstallingDebianOn/Samsung/ARMChromebook

For most people I would recommend that approach since it's a lot less risky
and better tested.

-- 
David Hendricks (dhendrix)
Systems Software Engineer, Google Inc.