about summary refs log tree commit diff
path: root/nixpkgs/nixos/modules/system/boot/loader/external/external.md
blob: 4f5b559dfc40d2b397057caeb11ea719356efe32 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
# External Bootloader Backends {#sec-bootloader-external}

NixOS has support for several bootloader backends by default: systemd-boot, grub, uboot, etc.
The built-in bootloader backend support is generic and supports most use cases.
Some users may prefer to create advanced workflows around managing the bootloader and bootable entries.

You can replace the built-in bootloader support with your own tooling using the "external" bootloader option.

Imagine you have created a new package called FooBoot.
FooBoot provides a program at `${pkgs.fooboot}/bin/fooboot-install` which takes the system closure's path as its only argument and configures the system's bootloader.

You can enable FooBoot like this:

```nix
{ pkgs, ... }: {
  boot.loader.external = {
    enable = true;
    installHook = "${pkgs.fooboot}/bin/fooboot-install";
  };
}
```

## Developing Custom Bootloader Backends {#sec-bootloader-external-developing}

Bootloaders should use [RFC-0125](https://github.com/NixOS/rfcs/pull/125)'s Bootspec format and synthesis tools to identify the key properties for bootable system generations.