liminix-fork/modules/outputs/ubimage.nix
Daniel Barlow f61e737b54 improve doc for outputs and hardware
Changed my mind about "installer" as a first-class concept, at least
in the current implementation. Not every documented output is an
installer
2023-11-12 17:15:58 +00:00

126 lines
3.5 KiB
Nix

{
config
, pkgs
, lib
, ...
}:
let
inherit (lib) mkIf mkEnableOption mkOption types concatStringsSep;
cfg = config.boot.tftp;
instructions = pkgs.writeText "env.scr" ''
setenv serverip ${cfg.serverip}
setenv ipaddr ${cfg.ipaddr}
setenv loadaddr ${cfg.loadAddress}
'';
in {
options.system.outputs = {
ubimage = mkOption {
type = types.package;
description = ''
ubimage
*******
This output provides a UBIFS filesystem image and a small U-Boot script
to make the manual installation process very slightly simpler. You will
need a serial connection and a network connection to a TFTP server
containing the filesystem image it creates.
.. warning:: These steps were tested on a Belkin RT3200 (also known as
Linksys E8450). Other devices may be set up differently,
so use them as inspiration and don't just paste them
blindly.
1) determine which MTD device is being used for UBI, and the partition name:
.. code-block:: console
uboot> ubi part
Device 0: ubi0, MTD partition ubi
In this case the important value is ``ubi0``
2) list the available volumes and create a new one on which to install Liminix
.. code-block:: console
uboot> ubi info l
[ copious output scrolls past ]
Expect there to be existing volumes and for some or all of them to be
important. Unless you know what you're doing, don't remove anything
whose name suggests it's related to uboot, or any kind of backup or
recovery partition. To see how much space is free:
.. code-block:: console
uboot> ubi info
[ ... ]
UBI: available PEBs: 823
Now we can make our new root volume
.. code-block:: console
uboot> ubi create liminix -
3) transfer the root filesystem from the build system and write it
to the new volume. Paste the environment variable settings from
:file:`result/env.scr` into U-Boot, then run
.. code-block:: console
uboot> tftpboot ''${loadaddr} result/rootfs
uboot> ubi write ''${loadaddr} liminix $filesize
Now we have the root filesystem installed on the device. You
can even mount it and poke around using ``ubifsmount ubi0:liminix;
ubifsls /``
4) optional: before you configure the device to boot into Liminix
automatically, you can try booting it by hand to see if it works:
.. code-block:: console
uboot> ubifsmount ubi0:liminix
uboot> ubifsload ''${loadaddr} boot/uimage
uboot> bootm ''${loadaddr}
Once you've done this and you're happy with it, reset the device to
U-Boot. You don't need to recreate the volume but you do need to
repeat step 3.
5) Instructions for configuring autoboot are likely to be very
device-dependent. On the Linksys E8450/Belkin RT3200, the environment
variable `boot_production` governs what happens on a normal boot, so
you could do
.. code-block:: console
uboot> setenv boot_production 'led $bootled_pwr on ; ubifsmount ubi0:liminix; ubifsload ''${loadaddr} boot/uimage; bootm ''${loadaddr}'
On other devices, some detective work may be needed. Try running
`printenv` and look for likely commands, try looking at the existing
boot process, maybe even try looking for documentation for that device.
6) Now you can reboot the device into Liminix
.. code-block:: console
uboot> reset
'';
};
};
config = mkIf (config.rootfsType == "ubifs") {
system.outputs = {
ubimage =
let o = config.system.outputs; in
pkgs.runCommand "ubimage" {} ''
mkdir $out
cd $out
ln -s ${o.rootfs} rootfs
ln -s ${instructions} env.scr
'';
};
};
}