The easiest way to launch custom scripts, change hidden settings, and run actions on Kobo eReaders.
See the website and thread on MobileRead for screenshots and more details.
You can download pre-built packages of the latest stable release from the releases page, or you can find bleeding-edge builds of each commit from here.
After you download the package, copy KoboRoot.tgz into the .kobo folder of your eReader, then eject it.
After it installs, you will find a new menu item named NickelMenu with further instructions which you can also read here.
To uninstall NickelMenu, just create a new file named uninstall in .adds/nm/, or trigger the failsafe mechanism by immediately powering off the Kobo after it starts booting.
Most errors, if any, will be displayed as a menu item in the main menu. If no new menu entries appear here after a reboot, try reinstalling NickelMenu. If that still doesn't work, connect over telnet or SSH and check the output of logread.
NickelMenu is designed to be compiled with NickelTC. To compile it with Docker/Podman, use docker run --volume="$PWD:$PWD" --user="$(id --user):$(id --group)" --workdir="$PWD" --env=HOME --entrypoint=make --rm -it ghcr.io/pgaskin/nickeltc:1.0 all koboroot. To compile it on the host, use make CROSS_COMPILE=/path/to/nickeltc/bin/arm-nickel-linux-gnueabihf-.