You will encounter recovery mode when the BIOS is unable to find a valid kernel to boot, either because the SSD has become corrupted or (more likely) because you modified all the kernel partitions while in developer mode and have switched back to normal mode. While in developer mode, you will be presented with the scary boot screen at every boot. Pressing SPACE or RETURN will take you to recovery mode.
This page contains information about the Cr-48 Chrome Notebook 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.
You might want to enter developer mode if you're following the instructions in the Chromium OS Developer Guide, or if you just want to get access to a shell on your device to poke around. To get your device into Developer Mode, you'll need to flip the developer switch to the "Developer Mode" position.
Caution: Modifications you make to the system are not supported by Google, may cause hardware issues and may void warranty.
The first time a Chrome Notebook boots in Developer Mode after leaving Normal Mode it will:
Here are some pictures that might help:
Image 2: Developer Switch in "Developer Mode" position.
If you are trying to install your own disk image onto your Cr-48 Chrome Notebook (maybe you're following the Chromium OS Developer Instructions), you need the recovery kernel. You can find it at: https://dl.google.com/dl/edgedl/chromeos/recovery/mario_recovery_kernel.zip
First, assuming you haven't modified anything, the first time you boot in normal mode after leaving developer mode, the stateful partition will be erased. This is a much faster erase process than when entering developer mode, usually only 30 or 40 seconds, and only happens with the first boot.
Second, verified boot will be enabled, meaning that only Google-signed images will be bootable. If you haven't modified the original kernel or rootfs partitions in any way, you should have no problems. If you've made changes to the kernel partitions, the Cr-48 will refuse to boot that kernel and will display a recovery screen. You'll have to create a recovery USB drive to restore your Cr-48 to the factory condition. If you've made changes to the rootfs partition but not the kernel, the Cr-48 may appear to boot normally, but may later suddenly reboot and/or display the recovery screen. This happens because the kernel verifies the rootfs as each block is read from the SSD, so it may not encounter a modified block until sometime later. When it does, it will reboot immediately.
You can also force your Cr-48 into recovery mode (even in normal mode) by using the recovery mode button.
On the bottom of the Cr-48, directly below the ESC key, there is a tiny pinhole:
If you stick a paperclip into this hole, you'll feel it press a button. To force recovery mode, turn the Cr-48 off, press this button, and while keeping it pressed, turn the Cr-48 on again. This sometimes requires three hands or a bit of contortion, but you'll know it worked when you see the recovery screen instead of booting normally.
There is little use for this button other than booting a recovery USB drive. In developer mode you can run your own scripts from the recovery USB drive, but in developer mode you can trigger recovery mode by just pressing SPACE at boot. Still, there it is.
Sometimes, you just want to have a shell or maybe you want to install another operating system. If you're in Developer Mode, then you can totally do that.
This tip could actually be useful to someone who wasn't a Chromium OS developer. However, at the moment the only easy way to get the tools is to follow many of the steps in the Chromium OS Developer Guide. If you don't care about developing for Chromium OS and just want to get to booting your own stuff, you should read the developer guide with these thoughts in mind:
The rest of the instructions will assume that you've followed the instructions enough to make a chroot and that you're currently in the chroot.
You'll need to get a "recovery kernel" for your Chrome OS Notebook in order to follow these instructions. The instructions for that are also in the Developer Guide, though in a different context. You should follow the instructions in the section "Get the Recovery Kernel for your Chrome OS Notebook" under the section Getting your image running on a Chrome OS Notebook.
Now, use make_developer_script_runner.sh. The script will create a file called
...assuming your disk was detected, it should print out as a result of that command. For instance, on my computer, I see this, which tells me that my USB disk is in
ALSO: If you mistype this step (don't put the right /dev/sdX in the command), it can blow away some other disk on your computer.
Really, I'm serious. Be very careful. If you shoot yourself in the foot with these instructions, you only get to blame yourself.
OK, now that you've read all of the disclaimers, the command you'll need to enter is this, replacing
TODO: You may need to unmount your USB disk before running this instruction if Ubuntu mounted it for you. Put a set of instructions that tell how to do that.
Now, shut off your Chrome OS Notebook and turn it back on. Since you're in Developer Mode (right?), you should see the warning. Hit the space bar to enter recovery mode. Once prompted, insert your USB disk.
Assuming that you haven't reimaged the built-in SSD with a developer-signed image, you'll need to wait 5 minutes each time you boot up with this disk image. This is a security precaution, to prevent someone from quickly rebooting your device from their USB key while you're getting more coffee (see the Developer Mode design document).
TODO: This should be possible for someone skilled in the art of Linux. The above instructions tell you how to run any arbitrary Linux program, and (with root access) you should be able to do pretty much anything you want.
It would be nice to get some good instructions here, though.
There's an example of configuring a Cr-48 to dual-boot Chrome OS and Ubuntu here.
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.
Here is a rundown of the parts that are not soldered down:
Taking apart your laptop is not encouraged. If you have hardware troubles, please seek assistance from a friend knowledgeable in the area. If you just want to see what the inside looks like, gaze upon this (click for a high res version):
However, we acknowledge that some people like to tinker. So here's a quick guide to taking it apart:
You now have access to the upgradable components.