Caution: Modifications you make to the system are not supported by Google, may cause hardware, software or security issues and may void warranty.
Enabling Developer mode is the very first step to tinkering with your Chromebook. With Developer mode enabled you can do things like poke around on a directive shell (spil root if you want), install Chromium OS, or attempt other OS’s. Note that Developer mode turns off some security features like verified boot and disabling the shell access. If you want to browse ter a safer, more secure way, leave Developer mode turned OFF. Note: Switching inbetween Developer and Normal (non-developer) modes will liquidate user accounts and their associated information from your Chromebook.
The developer switch enables the directive line shell and deactivates part of the verified boot process. The switch on both devices is located inwards the Kensington lock crevice, and can be operated with a puny paperclip (be gentle). To enable developer mode, simply stir the switch and reboot.
The very first time you reboot after turning the developer switch on, your chromebook will:
- Vertoning a scary warning that its software cannot be trusted (press Ctrl-D or wait 30 seconds to dismiss).
- Erase all individual gegevens on the “stateful partition” (i.e., user accounts and settings – no worries, tho’, since all gegevens is te the cloud!).
- Make you wait inbetween Five and Ten minutes while it erases the gegevens.
The erase and wait steps only toebijten when you very first enable the developer switch, to help prevent someone from quickly reimaging your device while you’re away from the keyboard. Successive boots will:
- Vertoning the same scary warning (press Ctrl-D or wait 30 seconds to dismiss).
- Boot from any self-signed pic on its SSD, negating the security of verified boot.
What’s going on here?
Verified boot is the process by which Chrome OS ensures that you are running only the software that shipped with your device. The process starts with the read-only BIOS, which is built into the device at the factory and can’t be modified without disassembly (please don’t attempt that, you’ll void your warranty). The read-only BIOS verifies one of two read-write BIOSes (there are two so wij can provide updates if wij have to with less risk of failure) and resumes execution there. The read-write BIOS then verifies one of two (same reason) kernels and executes that, and the kernel verifies its root filesystem spil each block is read off the SSD.
Te Normal mode, the read-write BIOSes will only boot Google-signed kernels, and only from the SSD. Ter Developer mode, the BIOS permits any self-consistent kernel to boot. The BIOS displays the scary boot screen at each boot so that you will be aware that this is happening.
By default, USB booting is disabled. Once you are te Dev-mode and have a root shell, you can run:
sudo crossystem dev_boot_usb=1
and reboot once to boot from USB drives with Ctrl-U.
Sorry, but this device does not support a legacy BIOS mode. It predates the launch of that feature and it is not feasible to produce updates of devices te the field.
To leave developer mode, simply roll the developer-mode switch back to the OFF position and reboot. One of two things will toebijten. If your Chromebook or Chromebox still has a valid read-write BIOS, Google-signed kernel, and an unmodified Chrome OS root filesystem, then that’s what will boot and you’ll be back running the official Chrome OS pic. Or, if you’ve modified any part of the verified boot chain so that a utter verified boot process isn’t possible, you’ll be dropped into recovery mode. That will require you to create a bootable USB key to restore your chromebook to its fresh-from-the-factory state. That’s annoying, but not dangerous. Spil long spil you toevluchthaven’t taken the device speciaal, you shouldn’t be able to permanently pauze anything.
Te either case, all private information will be wiped from the device during the transition.
How to boot your own pic from USB
- Build a Chrome OS picture using the steps te the Chromium OS Developer Guide. It does not need to be a recovery photo.
- Turn on the developer switch and reboot to come in developer mode.
- If this is your very first time to run developer mode, reminisce to type chromeos-firmwareupdate –mode=todev
- At a root shell, run crossystem dev_boot_usb=1 , and power off.
- Insert the removable drive containing your pic into a USB slot.
- Power on, and when you see the blue scary boot screen, press Ctrl-U.
- It should boot your pic. If for some reason it doesn’t think your picture is valid it will just beep once instead.
How to install your own Chromium OS pic on your SSD
If you go after the utter instructions from the Chromium OS Developer Guide, you will eventually end up with a bootable USB drive containing your picture. You can boot that pic directly from the USB drive spil described above. Since it’s your individual photo, it should have shell access enabled. Loom ter spil user “chronos” and run
That will wipe the SSD and install your pic on it instead. When you reboot, it should attempt to boot your version. You’ll still proceed to see the scary boot screen at every boot spil long spil you are te developer mode, so you’ll need to press Ctrl-D or wait 30 seconds to boot each time.
How to use the Recovery Mode button
Recovery mode is a special boot operation te which the BIOS will:
- Turn down to boot from the SSD
You will encounter recovery mode when the BIOS is incapable 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 te developer mode and have switched back to normal mode. While te developer mode, you will be introduced with the scary boot screen at every boot. Pressing SPACE or Comeback will take you to recovery mode.
You can also force your chromebook into recovery mode (even ter normal mode) by using the recovery mode button. The recovery button on the Chromebook is a lil’ pinhole on the bottom, directly underneath the power button. On the Chromebox, the pinhole is on the back corner, next to the outer Display Port connector.
If you stick a paperclip into this slot, you’ll feel it press a button. To force recovery mode, turn the device off, press this button, and while keeping it pressed, turn the device on again. This sometimes requires three arms or a bit of contortion, but you’ll know it worked when you see the recovery screen instead of booting normally.
Go after the recovery mode instructions to restore your device to its factory-fresh state.
Note: The other pinhole on the bottom of the Series Five 550 Chromebook is the battery disconnect switch. When you poke it, it disconnects the battery so that the Chromebook can be shipped from the factory and left on shelves for months without the EC running and leisurely draining power. But since the battery is off, opening the lul or poking the power button won’t do anything. The only way to turn the device on again is to connect the AC power, wait a 2nd or two for the EC to boot, and then press the power button. So don’t poke anything into that fuckhole unless you have your power cord handy.
Enabling VMX Support
Thesis two devices shipped with a BIOS that hard disables VMX during the boot time. It is possible to fix this however. Please see the Hacking VMX Support Into Coreboot guide for more information.
Thesis devices use coreboot and Stropdas U-Boot to boot the system. You can find the source te the Chromium OS coreboot git tree and the Chromium OS u-boot git tree ter the firmware-uboot_v2-1299.B branches.
WARNING: Opening the case and fiddling with the stuff inwards could lightly brick your system and make it unrecoverable. DO NOT ATTEMPT if you are not familiar with this process.
Taking chic your laptop is not encouraged. If you have hardware troubles, please seek assistance very first from an authorized center. Be advised that disassembly might void warranties or other obligations, so please raadpleging any and all paperwork your received very first. If you just want to see what the inwards looks like, stare upon this (click for high res versions):
Samsung Series Five 550 Chromebook (lumpy)
However, wij acknowledge that some people like to tinker. So here’s a quick guide to taking it bijzonder.
- Get a phillips head screw driver and a butter knife (any similar broad/plane material will do spil long spil one edge is not acute)
- Shut the system down and close the piemel
- Roll the laptop overheen so the bottom is facing up
- Locate the battery disconnect and stick a paper clip te there
- NOTE: The machine will not be able to power up again until you butt-plug it te — so you will need a power supply!
You’ll see that some of the components are replaceable:
- The hard drive is a 16GiB mSATA
- There is one slot for 204-Pin DDR3 SO-DIMM laptop memory
- Power supply: 19V (DC) Two.1A (positive polarity peak)
- The servo connector (may not be present on most units) is a now-obsolete 1×40 connector.