nixos-hardware/purism/librem/5r4

Purism Librem 5 revision 4

Purism's Librem 5 is a privacy-oriented Linux-friendly smartphone.

Installation procedure

Note

TODO: build a uuu-compatible installer.

Until there's a native installer, the easiest way to install NixOS on Librem 5 seems to be using Jumpdrive.

Jumpdrive

Jumpdrive is a tiny Linux distribution which presents device's internal storage as USB mass storage when you connect it to a PC. It also provides a shell session over telnet.

Follow the instructions in the repo to boot into Jumpdrive. Note that uuu is part of nxpmicro-mfgtools package in nixpkgs.

Now, plug the device into your PC. A new block device representing Librem 5's internal MMC should appear in /dev. Note down this device path.

U-Boot

Note

While upstream u-boot does support Librem 5, it can only boot using boot.scr, for which NixOS has no native support.

There's work on extlinux support in Librem 5's U-Boot here: https://source.puri.sm/a-wai/uboot-imx/-/tree/allow-compressed-kernel

This U-Boot version is packaged in the u-boot directory.

Provided you have a way to build Nix derivations for aarch64-linux (like a remote builder, binfmt emulation, or you're building it on the phone itself), just run nix-build u-boot/build.nix.

Warning

Even though I've tested this myself, I can't guarantee that this will not render your device unbootable. Proceed with caution.

If it does not work, your best bet is to follow the advice here, which will flash U-Boot build by upstream: https://forums.puri.sm/t/can-someone-with-serial-console-access-try-nixos-kernel-on-librem-5/19121/27

To flash the device, run

$ sudo u-boot-install-librem5 <path to librem 5's MMC>

At this point, if you have an OS installed on your Librem 5, it's best to reboot into it to check that the U-Boot was flashed correctly. If that's the case, reboot back into Jumpdrive.

Partitioning

Now, from your host system, partition the MMC.

Warning

Doing this wipes all data off the phone

I went with 1 bootable ext2 partition for /boot, and one ext4 partition for /. It ended up looking like this (your device names will be different):

$ sudo fdisk -l /dev/mmcblk0
Disk /dev/mmcblk0: 29.12 GiB, 31268536320 bytes, 61071360 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xcec26c32

Device         Boot  Start      End  Sectors  Size Id Type
/dev/mmcblk0p1 *      4096   499711   495616  242M 83 Linux
/dev/mmcblk0p2      499712 61071359 60571648 28.9G 83 Linux

Note 2MiB of free space before the first partition. This is where U-Boot lives.

Mount the partitions on your host system, e.g. to /mnt and /mnt/boot. Remember that /mnt is the second partition, and /mnt/boot is the first.

Installation

Now, write your NixOS config. Use /dev/mmcblk0p1 as fileSystems."/boot" and /dev/mmcblk0p2 as fileSystems."/". Don't forget to import the module from this directory. If you plan to use the device as a smartphone, you have a choice of two "desktop" (?) environments packaged in nixpkgs: phosh and Plasma Mobile.

Build the configuration (nix build .#nixosConfigurations.<hostname>.config.system.build.toplevel if you're using flakes).

Running nixos-install --system ./result --root /mnt will copy the system to the MMC. Unless you're running on an aarch64 system, it will fail to activate or install the bootloader, however. You must do this manually. Get a shell on Jumpdrive, mount partitions there, and activate the system:

$ nc 172.16.42.1 23
# mkdir /mnt
# mount /dev/mmcblk0p2 /mnt
# mkdir -p /mnt/boot
# mount /dev/mmcblk0p1 /mnt/boot
# chroot /mnt /nix/var/nix/profiles/system/activate
# chroot /mnt /nix/var/nix/profiles/system/bin/switch-to-configuration boot

Provided the last command succeeds, you now should have a bootable device.

Unmount:

# sync
# umount /mnt/boot
# umount -l /mnt
# echo u > /proc/sysrq-trigger
# echo s > /proc/sysrq-trigger

And shut the phone down by holding the power key.

Start it up and you should be booting straight into your NixOS installation.