This page contains information about the Chromebook Pixel that is interesting and/or useful to software developers. For general information about getting started with developing on Chromium OS (the open-source version of the software on the Chrome Notebook), see the Chromium OS Developer Guide.
On this device, both the recovery button and the dev-switch have been virtualized.
To invoke Recovery mode, you hold down the ESC and Refresh keys and briefly hold the Power button (if you hit it too fast it won't work).
To enter Dev-mode you first invoke Recovery, and at the Recovery screen press Ctrl-D (there's no prompt - you have to know to do it). It will ask you to confirm, then reboot into dev-mode.
Dev-mode works the same as always: It will show the scary boot screen and you need to press Ctrl-D or wait 30 seconds to continue booting.
You'll still have to run
and reboot once to boot from USB drives with Ctrl-U.
Caution: Modifications you make to the system are not supported by Google, may cause hardware, software or security issues and may void warranty.
To leave Dev-mode and go back to normal mode, just follow the instructions at the scary boot screen. It will prompt you to confirm.
If you want to leave Dev-mode programmatically, you can run "crossystem disable_dev_request=1; reboot" from a root shell. There's no way to enter Dev-mode programmatically, and just seeing the Recovery screen isn't enough - you have to use the three-finger salute which hard-resets the machine first. That's to prevent a remote attacker from tricking your machine into dev-mode without your knowledge.
An unrelated note: Holding just Refresh and poking the Power button hard-resets the machine without entering Recovery. That's occasionally useful, but use it with care - it doesn't sync the disk or shut down politely, so there's a nonzero chance of trashing the contents of your stateful partition.
Installing Linux to the SSD
See the excellent write up by David Miller here: http://vger.kernel.org/~davem/chromebook_pixel_linux.txt
Make sure you don't have your Pixel stacked on top of another Pixel (or possibly other laptop), as the sensor for detecting the screen closed will activate from the magnet in the device below, preventing booting.
The Pixel firmware saves an event log to read-write flash that can be useful for troubleshooting your device.
The event log is based on SMBIOS Type 15 Event Log format, but uses a number of OEM events to provide additional information. The mosys application that is part of Chromium OS can be used to read and decode the log by running mosys eventlog list as the root user in Chrome OS if the device is in developer mode or opening chrome://system and looking for the eventlog entry in normal/verified mode.
Mosys can also be compiled on other Linux distributions, here are instructions for Ubuntu that assume basic build and source control tools are installed. Unfortunately these same instructions do not work on Fedora because it does not provide static libraries for things like UUID.
WARNING: Opening the case and fiddling with the stuff inside could easily brick your system and make it unrecoverable. DO NOT ATTEMPT if you are not familiar with this process. Really, just don't.
Taking apart your Chromebook is not encouraged. If you have hardware troubles, please seek assistance first from an authorized center. There's nothing inside that you can fix yourself. Be advised that disassembly might void warranties or other obligations, so please consult any and all paperwork you received first. If you just want to see what the inside looks like, gaze upon this (click for a high res version):
Fine. If you must risk breaking it for good, at least do it the right way.