HP Pavilion 14 Chromebook Stock Firmware Backup Needed

[Gary Cooper]

Hi,

So I have used John Lewis' coreroot build for the HP Pavilion 14 chromebook to install Ubuntu, it work and have used Ubuntu for some time but I think I want to sell the device so trying to get it back to stock ChromeOS. Stupidly I didn't back up the stock firmware before I did this. 

Could someone point me in the right direction to get it? 

Thanks 

[Mike Frysinger]

i don't know which device exactly you're referring to as there is no "HP Pavilion 14 Chromebook", but there is the older "HP Pavilion Chromebook" and the newer "HP Chromebook 14".  the former didn't support legacy boot so you'd need a custom firmware to boot Ubuntu directly w/out building the kernel specially, but the latter includes legacy mode (CTRL+L) so no firmware modification should be necessary.  you will need to know the exact model though in order to download the correct recovery/firmware image.

that said, i don't know exactly the process you went through, but the SPI flash includes multiple sections -- the firmware itself, as well per-device factory settings (like serial #), so hopefully that wasn't blown away :).

every CrOS recovery image actually includes the firmware so you could extract it from that.  this file:
  https://dl.google.com/dl/edgedl/chromeos/recovery/recovery.conf

indexes the latest recovery image for each board.  fetch the right one, then unzip it, then do:

  losetup -P /dev/loop0 <bin file>

then mount the rootfs:

  mount -o ro /dev/loop0p3 /mnt/somewhere

then you have the firmware script:

  /mnt/somewhere/usr/sbin/chromeos-firmwareupdate

you can get the files themselves by using the --sb_extract flag, but the bios.bin in there is the full flash image and won't include the factory data.  so you will have to manage extracting the specific coreboot payload/whatever and writing it to your flash.  you might be able to get away with running that script directly with --mode recovery ... not entirely sure.  but you can pop open the script itself to see what the different modes do.

-mike

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[Gary Cooper]

So to clarify, I have the HP Pavilion Chromebook c-002sa. I know its hardware id is named butterfly but that's it. I know it's serial number as its on the bottom of the device. 

The .rom I used to flash the SPI was from here:
http://johnlewis.ie/custom-chromebook-firmware/rom-download/

and I followed his instructions on how to flash it 

Would you be able to make your instructions more explict? I do Electrical Engineering at University but I don't have much experience in reflashing an SPI :P

[Mike Frysinger]

"butterfly" is all you need then as the recovery.conf is indexed by board name.  that is the older "HP Pavilion Chromebook".

i can't currently slap together more specific directions for you at this time (travelling).  maybe someone else can ;).

-mike

[Gary Cooper]

So I do

sudo  losetup -p /dev/mapper/loop0 chromeos_5712.88.0_butterfly_recovery_stable-channel_mp-v3.bin

and I get an error saying 

"Inappropriate ioctl for device"

Any idea? 

On Sunday, 6 July 2014 16:39:26 UTC

[Gary Cooper]

The full error. 

loop: can't get info on device chromeos_5712.88.0_butterfly_recovery_stable-channel_mp-v3.bin: Inappropriate ioctl for device

[Mike Frysinger]

-p is not the same as -P.  i used the latter while you used the former.

-mike

On Mon, Jul 7, 2014 at 3:01 AM, Gary Cooper <gary...@googlemail.com> wrote:

So I do

sudo  losetup -p /dev/mapper/loop0 chromeos_5712.88.0_butterfly_recovery_stable-channel_mp-v3.bin

and I get an error saying 

"Inappropriate ioctl for device"

Any idea? 

[Gary Cooper]

I only did that because when I used -P it gives the help options on how to use "mount". Thought it was a typo. 
"P" is invalid it says as a return. 

[Mike Frysinger]

your util-linux is out of date.  you should upgrade it ;).

-mike