[solved] Nohibernate option added to kernelParams and I don't know where it comes from

Help
1

I am new to NixOS and i managed to set up my Laptop based on hlissners dotfiles.
my config so far: https://github.com/stfl/dotfiles
the host is trex

I am trying to configure hibernate.
I have a swap partition and to my knowledge everything should work…

The problem seams to be the kernelParam nohibernate which is automatically added and I have no idea where it comes from.

Is there a nix command to identify where (and why) this option was added?
or is there an option to manually remove the option in my hardware-configuration.nix file?

2

Are you sayimg that it has been added to that file automatically? That strikes me as odd.

You shouldn’t modify it by hand, but you can override what hardware-configuration.nix sets in configuration.nix using lib.mkOverride. E.g., to turn off all kernel parameters:

boot.kernelParams = lib.mkOverride 999 [];

Or to be a little less aggressive (at least I think this works, if you get a recursion error, my bad):

boot.kernelParams = lib.mkOverride 999 (builtins.filter (p: p != "nohibernate") config.boot.kernelParams);

It would indeed be better to figure out how it ended up in your config, though. It might come from https://github.com/NixOS/nixos-hardware, which if you’re not using yet you should :slight_smile:

3

This is a result of enabling the security.protectKernelImage option in modules/security.nix. This will automatically set nohibernate.

2 Likes
4

thank you pointing me towards config.security.protectKernelImage
searching through nixpkg repo would have given me an answer. now I know another place to look. thanks.

Besides manually looking through code, is there a way trace back all the places where a given config was set? This would be a great debugging feature.

5

Yes, nixos-option boot.kernelParams should be able to list all the places that touched the option. It is stuck on nix 2.3 right now though so it can be a bit janky. (I realised when trying to make an example that it broke again on my setup)

1 Like
6

You could use nix eval or nix repl to inspect where options were declared.

$ nix eval github:stfl/dotfiles\#nixosConfigurations.trex.options.boot.kernelParams.files
[ "/nix/store/60lvjx4513hq50qnq73bjxm7cyg0bdnw-source/hosts/trex/hardware-configuration.nix" "/nix/store/1mq6ivn9y8zkjljiy66d4xjjhlhq0h3r-source/nixos/modules/system/boot/systemd.nix" "/nix/store/1mq6ivn9y8zkjljiy66d4xjjhlhq0h3r-source/nixos/modules/system/boot/kernel.nix" ]

$ nix repl                                                                               
Welcome to Nix 2.8.1. Type :? for help.

nix-repl> flake = builtins.getFlake "github:stfl/dotfiles"                      

nix-repl> flake.nixosConfigurations.trex.options.boot.kernelParams.files        
[ "/nix/store/60lvjx4513hq50qnq73bjxm7cyg0bdnw-source/hosts/trex/hardware-configuration.nix" "/nix/store/1mq6ivn9y8zkjljiy66d4xjjhlhq0h3r-source/nixos/modules/system/boot/systemd.nix" "/nix/store/1mq6ivn9y8zkjljiy66d4xjjhlhq0h3r-source/nixos/modules/system/boot/kernel.nix" ]
3 Likes