*

Quick hack: Removing the Chromebook Write-Protect screw

Robert Foss avatar

Posted on 08/03/2017 by Robert Foss

Share this post:

Before being able to write firmware data to any production Chromebook device, the Write-Protect screw has to be removed.

This post will look specifically at removing the WP screw from a Chell (HP Chromebook 13 G1) device, and verifying that it has been successfully removed.

To actually flash firmware to Chromebook machines, a device called a Servo is needed. While these devices aren't available publicly, they can be produced freely or possibly requested from Google if you are contributing code to the ChromiumOS project.

Removing the Write-Protect screw

WP screw on Chell Chromebook

So this is what the WP screw looks like on a Chell Chromebook. This may or may not be what you will find in other devices. But if you take a close look, you will notice that the copper pad that the the screw attaches against is split into parts that are bridged by a screw being inserted.

Disable Write-Protect

So this is the part that requires a Servo device. And a ChromiumOS checkout, for some help setting one up, have a look at my previous post.

# Go to your ChromiumOS checkout
cd /opt/chromiumos

# Enter dev environment
cros_sdk

# Set device variable
export BOARD=chell

# Connect to Chromebook using a Servo device
sudo servod -b $BOARD &

# Disable WP
# This step may vary depending on the hardware of your actual Chromebook
dut-control fw_wp:off
sudo /usr/sbin/flashrom -p ft2232_spi:type=servo-v2 --wp-disable
sudo /usr/sbin/flashrom -p ec --wp-disable

 

References

ChromiumOS Servo
Setting up a ChromiumOS dev environment

 

Thanks!

This post has been a part of work undertaken by my employer Collabora.

 

Original post

Comments (13)

  1. Michael A Hall:
    Jan 15, 2018 at 09:33 PM

    Can you replace the screw after flashing?

    Reply to this comment

    Reply to this comment

    1. Robert Foss:
      Jan 16, 2018 at 03:16 PM

      Hi Michael,

      Yes you can! As far as my experience has been, the screw only protects against writes.
      If there write have already happened, you're good.


      Rob.

      Reply to this comment

      Reply to this comment

  2. Conundrum:
    Feb 14, 2018 at 09:28 AM

    Hi, yes this is by design to prevent malware messing with the unit.
    Unfortunately it also makes repairs harder, if the uEFI gets corrupted the unit is bricked until opened, screw removed and re-flashed.
    I did look into using a "magic" SD card as a workaround, as some netbooks can be jigged using a BIOS update that enables the missing function, essentially it stores the boot sector in high memory > 2MB and provides a "boot SD" option.

    Reply to this comment

    Reply to this comment

  3. lloyd:
    Feb 22, 2018 at 04:17 PM

    where wp screw on hp chromebook 11.6 v020wm

    Reply to this comment

    Reply to this comment

    1. Robert Foss:
      Mar 01, 2018 at 07:13 AM

      Hey Lloyd,

      No, unfortunately I don't have access to that hardware or documentation for it.
      If you look at the PCB the WP-screw will likely have a split exposed copper ring, which the metal screw bridges.


      Rob.

      Reply to this comment

      Reply to this comment

  4. AG:
    Feb 26, 2018 at 12:55 AM

    DO YOU KNOW WHERE IS THE write-protect screw chromebook lenovo n21 PLEASE HELP ME

    Reply to this comment

    Reply to this comment

    1. Robert Foss:
      Mar 01, 2018 at 07:13 AM

      Hey Ag,

      No, unfortunately I don't have access to that hardware or documentation for it.
      If you look at the PCB the WP-screw will likely have a split exposed copper ring, which the metal screw bridges.


      Rob.

      Reply to this comment

      Reply to this comment

  5. Gavin:
    Apr 26, 2018 at 04:43 AM

    Does anyone know where the write-protect screw is on the lenovo n23?

    Reply to this comment

    Reply to this comment

    1. Lenovo Support Number:
      Aug 08, 2018 at 06:01 AM

      It'll be the screw with the large flat chrome head, near what looks like the Wi-Fi card, with a split solder pad underneath it.

      Reply to this comment

      Reply to this comment

  6. Toshiba Bios:
    Oct 24, 2018 at 06:56 AM

    Thanks, Robert, I successfully removed the screw from the Chromebook. Things tend to get a little easier when you look around the web. Nice hack!

    Reply to this comment

    Reply to this comment

  7. HP printer in error state:
    Nov 02, 2018 at 12:23 PM

    I want to install Gallium OS on my Chromebook, but I can't find the write protect screw on my Samsung. I am not sure if there is a write-protect screw on the Samsung Chromebook 3.

    Reply to this comment

    Reply to this comment

    1. Robert Foss:
      Nov 03, 2018 at 05:30 PM

      Hey!

      Unfortunately I don't have information about other devices.

      If a WP screw exists it can be identified by the screw itself bridging two connections.


      Rob.

      Reply to this comment

      Reply to this comment


Add a Comment






Allowed tags: <b><i><br>Add a new comment:


Latest Blog Posts

Quick hack: Speed up your GitLab CI

06/11/2018

Did you know you could register your own PC, or a spare laptop collecting dust in a drawer, to get instant CI going on GitLab? Not only…

Introducing Zink, an OpenGL implementation on top of Vulkan

31/10/2018

For the last month or so, I've been playing with a new project during my work at Collabora, and as I've already briefly talked about at…

On the low adoption of automated testing in FOSS

18/10/2018

For projects of any value and significance, having a comprehensive automated test suite is nowadays considered a standard software engineering…

Recently in Geoclue

12/10/2018

After I started working for Collabora in April, I've finally been able to put some time on maintenance and development of Geoclue again.…

The beauty of Open Source

10/10/2018

Like all software, Open Source software isn't without it's bugs and issues. However, thanks to the nature of Open Source, resolving or mitigating…

MicroDebConf Brasilia

02/10/2018

Last month, the first "MicroDebConf" took place at the Gama campus of the University of Brasilia. Here's a look at how this one day event…

Open Since 2005 logo

We use cookies on this website to ensure that you get the best experience. By continuing to use this website you are consenting to the use of these cookies. To find out more please follow this link.

Collabora Ltd © 2005-2018. All rights reserved. Website sitemap.