https://github.com/thefloweringash/kevin-nix
NixOS for the Samsung Chromebook Plus (kevin)
https://github.com/thefloweringash/kevin-nix
chromebook nixos
Last synced: 5 months ago
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NixOS for the Samsung Chromebook Plus (kevin)
- Host: GitHub
- URL: https://github.com/thefloweringash/kevin-nix
- Owner: thefloweringash
- License: mit
- Created: 2018-01-13T18:21:38.000Z (over 7 years ago)
- Default Branch: master
- Last Pushed: 2021-09-06T20:51:10.000Z (about 4 years ago)
- Last Synced: 2025-04-03T17:53:44.475Z (6 months ago)
- Topics: chromebook, nixos
- Language: Nix
- Size: 121 KB
- Stars: 30
- Watchers: 6
- Forks: 2
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# NixOS on Samsung Chromebook Plus
This project is a configuration of NixOS that renders it bootable on a
Samsung Chromebook Plus in the form of a image that can be dumped to a
microSD card and booted directly. The majority of the effort was
accomplished by the [Arch Linux ARM][] project, which builds an
[appropriate kernel][], which was imported directly.
[Arch Linux ARM]: https://archlinuxarm.org
[appropriate kernel]: https://github.com/archlinuxarm/PKGBUILDs/tree/master/core/linux-gru
## Status
Weekend hobby project. Works for me.
## Building
```
nix-build release.nix -A sdImage
```
Or try `./simple-build.sh`.
## Installation
1. Place device in [Developer Mode][]
2. Dump image to SD card.
3. Insert into Chromebook.
4. Boot with Ctrl-U.
[Developer Mode]: https://www.chromium.org/a/chromium.org/dev/chromium-os/developer-information-for-chrome-os-devices/generic
## Post installation configuration
Use the standard nixos-generate-config command to generate the
hardware and filesystem configuration file. In the main configuration
file (`configuration.nix`), include the two modules from this
repository's `modules/` directory, which adds in the kernel package,
and the depthcharge bootloader integration. In you main
configuration.nix, specify your desired kernel. For example:
```
{ config, lib, pkgs, ... }:
{
include = [
./kevin-nix/modules
];
boot.kernelPackages = pkgs.linuxPackages_gru_4_4;
boot.loader.depthcharge.enable = true;
boot.loader.depthcharge.partition = "/dev/disk/by-partlabel/kernel";
}
```
## nixos-rebuild switch
The boot process scans the media for a partition designated as a
kernel, using attributes stored in GPT.
This kernel partition (kpart) is a Flattened Image Tree (fit) image
including the kernel, a set of dtbs, the initrd, and the kernel
command line.
The depthcharge module will will produce a kernel partition (`kpart`)
file as part of the toplevel system, and on switch will write its
contents to the kernel partition.
The kernel partition is not a GC root. If you remove old versions of
your system profile, you may render your environment unbootable.
### Generated partition layout
```
$(nix-build --no-out-link -E 'import { overlays = [ (import ./packages) ]; }' -A vboot_reference)/bin/cgpt show $(readlink -f ./result/sd-image/*.img)
start size part contents
0 1 PMBR
1 1 Pri GPT header
2 32 Pri GPT table
2048 131072 1 Label: "kernel"
Type: ChromeOS kernel
UUID: 534078AF-3BB4-EC43-B6C7-828FB9A788C6
Attr: priority=10 tries=5 successful=1
133120 4393031 2 Label: "NIX_SD"
Type: B921B045-1DF0-41C3-AF44-4C6F280D3FAE
UUID: 0340EA1D-C827-8048-B631-0C60D4478796
4526151 32 Sec GPT table
4526183 1 Sec GPT header
```
Notice the additional metadata for the kernel partition `Attr:
priority=10 tries=5 successful=1`.
## Versions
Tested against nixpkgs f607771d0f5.
## Future work
* Make a fit image containing uboot, which can then use the standard
extlinux-based boot flow.
* Use a vanilla kernel. It is expected that 4.16 will include support
that enables the display without additional patches.
* Use depthcharge's fallback features to have multiple bootable
profiles.
* Build the open source Mali kernel module from ARM that matches the
[binary `libmali.so`][rockchip-linux/libmali] available from
rockchip.
[rockchip-linux/libmali]: https://github.com/rockchip-linux/libmali
## License
Everything original to this repository is MIT licensed. Packages are
naturally covered by their own licences. The linux_gru patches and
config files are from archlinuxarm which is covered by the GPLv2.