Subject: [bug#48314] Patches to install guix system on Raspberry Pi

From: Stefan <[email-masked]>
Date: Sun, 9 May 2021 17:32:04 +0200

Hi!

This patch series adds support for the Raspberry Pi. It allows to use ‘sudo -E guix system init … /mnt’ with the root partition mounted at /mnt and the boot partition mounted at /mnt/boot/efi, as you would expect it for a PC with UEFI. Installing for netboot is possible as well.

It is currently not possible to build an image with this patch series, because of the intercepting handling for efi system image creation.

Some of these patches are generic and not related to the Raspberry Pi. I hope they will be a useful contribution for everyone.

Here is a quick overview of the single patches:

01: Disable the tests on aarch64 for qemu-minimal, because it is non-deterministic but needed to build grub.

02: Rework the grub-efi-netboot-bootloader and add a grub-efi-netboot-removable-bootloader which then are pre-installed. This allows a simplification of the efi-bootloader-chain, as these pre-installed bootloaders just need to be copied and can therefore easily be collected in a bootloader-profile.

03: A new build-side module to modify a defconfig. It is used to customize U-Boot and Linux packages.

04: Customized and pre-installed U-Boot packages for the Raspberry Pi.

05: Fixed the EXTRAVERSION variable used to build Linux, so that the extra-version argument will be visible with uname. 

06: New function to modify a Linux package by using another defconfig and/or adding or removing configurations.

07: Raspberry Pi specific defconfig objects.

08: Some helpers to construct config.txt files for the Raspberry Pi firmware.

09: A function to create a package with device-tree files from a Linux package for the Raspberry Pi.

10: A bootloader for the Raspberry Pi. Additionally two examples of operating-system definitions to boot from local storage or over network, the latter is making necessary configuration changes to Linux.

The firmware topic is excluded. In the same way that guix assumes that some UEFI firmware is already present on a PC, this patch series assumes that a firmware to start U-Boot is already present.

The grub bootloaders are usable on PCs as well. In contrast to the normal grub-efi, all grub files are copied to the EFI system partition, instead of the root partition. This is a side effect of the netboot capability. Maybe this is helpful for some spacial cases. I realized for example that the normal grub-efi locates the partition containing the grub.cfg by a device name like (hd0,gpt1), this may be problematic when adding disks to a system. The new grub bootloaders determine the partition by UUID.

The new possibility to customize Linux with (modify-linux) will be useful for anyone in need to do small configuration changes. There is also the possibility to pass an own defconfig file to this function. It can either be the name of a defconfig file from the Linux sources, or it can be a file-like object, like produced by (local-file) or possibly downloaded with the new (make-defconfig) function.

Bye

Stefan