ECTool.efi is a tool for communicating with the embedded controller in the Framework Laptop (and potentially other devices with ChromeOS-derived embedded controllers) from the UEFI shell.


ECTool is part of a suite of tools for the Framework Laptop.

I primarily wrote ECTool to allow somebody to reflash their Embedded Controller safely1 from a pre-boot environment. This first release, therefore, only has a few firmware-related subcommands implemented.

Prebuilt binaries are available on the releases page of the GitHub repository.


ECTool is distributed in an archive containing a minimal EFI shell. Extract the entire archive to the root of a FAT32-formatted USB mass storage device, copy your desired firmware image to the root of the same device, turn off Secure Boot, and boot from it.

Reflashing your Firmware

Make sure that ECTool can communicate with your embedded controller:

Shell> ectool version

This should report something like…

ectool version output (shows some version numbers)

If it doesn’t, you may want to give up on this endeavor and file a bug report!

Take a backup (optional but recommended, especially if you have an external programmer in case things go terribly.)

Shell> ectool flashread 0 524288 fs0:\ec-backup.bin
ectool flashread

If you’re running a full UEFI shell (sorry, the one in the archive is built to be particularly tiny), you can verify the flash dump with hexedit fs0:\ec-backup-bin. It will look something like this at offset 0x1000. To quickly jump to an offset, use Ctrl+G.

hexedit displaying a recently-dumped flash

Finally, reflash. reflash will only flash 512kb firmware images, and only if the system is currently powered and charged to 20% or more. The power button will (should?) be disabled for the duration of the flash, which will take about a minute.

It is delightfully verbose.

Shell> ectool reflash fs0:\new-ec.bin
Unlocking flash... OK
Erasing RO region... OK
Erasing RW region... OK
Writing RO region... OK
Writing RW region... OK
Verifying: Read... OK. Check... RO OK... RW OK... OK
Locking flash... OK

Looks like it worked?
Consider running `ectool reboot` to reset the EC/AP.

  1. ectool (from the upstream CrOS EC project) can read/write flash with the OS running, but some ACPI methods are implemented by way of EC host commands. Having one of those interrupt a firmware update would likely be catastrophic. ↩︎