kos: a minimal operating system that runs KOReader

[ratiz]

kos is an open-source operating system that can replace the stock OS. It comes with KOReader as the graphical user interface.

Currently it only supports the Clara Colour, but if someone is interested I could easily add support for the Libra Colour and the Clara BW.

Compared to the stock OS, kos doesn't come with any additional features, except that it is certainly smaller. As you might know, the most recent Kobo models have a secure boot chain that makes it much harder to boot a different kernel. My intent with kos is to provide a simple, open-source OS that can serve as an example for further Kobo hacking. I hope that having more control over one's hardware will help make even better open-source software possible.

Because this installation will write to partitions essential for the boot process, it is much riskier than the installations you might usually find on this forum. If the installation goes wrong, it will likely brick your device. So far, it has only been tested on my kobo with firmware version 4.39.22468 and 4.46.23836 but I would expect it to work on all 4.x firmware versions.

Install:

Before the installation make sure that you have a Kobo Clara Colour and that it runs on firmware 4.x. Backup all your data as it will be erased during the installation.

For the installation, use the provided KoboRoot.tgz at the end of the post at your own risks. I am not responsibe if it bricks your device.

After the installation, to display your local time, set the time zone with:

# ln -sf /usr/share/zoneinfo/Area/Location /etc/localtime

To access a shell, you can use, for example, the terminal emulator provided by KOReader or its built-in SSH server.

Uninstall:

Run the command below and you will be back to the stock OS after reboot.

# ntx_hwconfig -S 1 -p /dev/mmcblk0p6 BootPartNo 0xB

Credits:

• tux-linux for creating Quill OS and helping me to learn how to make an operating system for a kobo device

Source Code | KoboRoot.tgz