projectmoon-overlay/README.md

Personal Gentoo overlay, focusing mostly on needed tools and
compatibility for a libre version of Gentoo on the Librem 14 computer.

Available packages:
 - **dev-python/ecp**: Python implementation of Emacs RPC stack. Depends
   on `orjson` or `orjson-bin` from the GURU (or another) overlay.
 - **sys-kernel/libre-kernel**: A dist-kernel built from the [Linux-libre
   sources][linux-libre].
 - **media-fonts/fonts-meta**: Modified version to remove non-Free
   fonts from the dependencies.
 - **sys-kernel/librem-ec-acpi**: An ebuild packaging the [Librem 14
    EC ACPI kernel module][ec-acpi], necessary for proper functioning
	of the laptop's battery charging and function keys.
 * **sys-power/librem-control**: A GTK application to control
   parameters of the Librem EC (battery charge levels, etc).
 * **sys-apps/purism_ectool**: Tool for querying and flashing
   Purism EC firmware images on certain Librem laptops.

## How to Add This Repository

Using eselect-repository:

```
# eselect repository add projectmoon git https://git.agnos.is/projectmoon/projectmoon-overlay
```

It usually a best practice to mask packages from overlays, except the ones you want:

In `/etc/portage/package.mask`:
```
*/*::projectmoon
```

Individual packages can be unmasked (and added to
`package.accept_keywords` if necessary). In `/etc/portage/package.unmask`:
```
sys-kernel/libre-kernel::projectmoon
virtual/dist-kernel::projectmoon
sec-keys/openpgp-keys-linux-libre::projectmoon
```

## The Linux-libre dist-kernel

This overlay provides a dist-kernel (based on
`sys-kernel/vanilla-kernel`) using the Linux-libre kernel sources, and
an accompanying updated version of `virtual/dist-kernel`. It is
maintained and tested for my personal use on amd64. The Linux-libre
kernel removes the ability for the Linux kernel to load firmware that
is not [Free Software][free-software]. The ebuild roughly follows the
current stable gentoo-kernel for amd64.

The libre kernel can be installed alongside other dist-kernels, and
works with the `dist-kernel` and `initramfs` USE flags. The ebuild
does NOT fail if non-free firmware (i.e. `sys-kernel/linux-firmware`
with `redistributable` USE flag set) is installed, but it will warn
you if this is the case. It will also warn you if the `linux-firmware`
package is not found at all, like normal dist-kernel ebuilds.

The kernel installed by this ebuild has the version suffix
`-gnu-dist`, making it easy to determine which kernel it is.


### Signature Verification

It is recommended to enable GPG signature verification of
`sys-kenrel/libre-kernel` by adding the USE flag to
`/etc/portage/package.use`:

```
sys-kernel/libre-kernel verify-sig
```

### Keeping the Linux-libre Kernel Installed

Portage will sometimes try to install `sys-kernel/gentoo-kernel` or
another dist-kernel if there is a newer stable version than
`sys-kernel/libre-kernel`. This happens because of a version bump to
`virtual/dist-kernel` before this overlay has updated its own copy of
`virtual/dist-kernel`.

To prevent portage from attempting to install another dist-kernel
instead of the Linux-libre kernel, you should mask other dist-kernels in
`/etc/portage/package.mask`:

```
# stay on libre kernel
sys-kernel/gentoo-kernel
sys-kernel/gentoo-kernel-bin
sys-kernel/vanilla-kernel
```

### Linux Firmware

*Note: If you are running the Linux-libre kernel, it is unlikely (though
not impossible) that you need to install `sys-kernel/linux-firmware`.*

To install only the Linux firmware that meets the [Free Software
Definition][free-software], configure `/etc/portage/package.use`
accordingly:

```
# Install only libre firmware
sys-kernel/linux-firmware -redistributable -unknown-license
```

You can also edit `/etc/portage/profile/package.use.mask` to prevent
the linux-firmware package from ever installing the closed-source
firmware by adding this line:

```
# forcibly stop non-free firmware installation
sys-kernel/linux-firmware redistributable unknown-license
```

## Using the Librem EC ACPI kernel module

The Librem EC ACPI kernel module should install and be automatically
available (via modprobe) after installation, using `emerge
sys-kernel/librem-ec-acpi`. The module is currently installed to
`/lib/modules/<kernel>/librem/`.

This ebuild supports the `dist-kernel` USE flag, and the module will
automatically be rebuilt when installing a new dist-kernel if that
flag is enabled.

If you are not using a dist-kernel, you will need to do `emerge
@modules-rebuild` to install the module after you upgrade or install a
new kernel,

### Librem Control and the Purism EC Tool

These two appliations can be used to manipulate device-specific
features of the Librem 14, including the flashing of firmware images.
It is not recommended to use the EC tool from this overlay for
flashing a firmware image. Instead, follow the official [firmware
flashing instrutions][ec-instructions].


# Disclaimer

The ebuilds in this overlay are really only tested for my specific
use-case. I do not test every combination of USE flags, for example.
So there may be issues with non-Free dependencies etc in some cases.

[linux-libre]: https://www.fsfla.org/ikiwiki/selibre/linux-libre/
[free-software]: https://www.gnu.org/philosophy/free-sw.en.html#fs-definition
[ec-acpi]: https://source.puri.sm/nicole.faerber/librem-ec-acpi-dkms
[ec-instructions]: https://puri.sm/projects/librem-ec/