# Way to profide .config file in cutom kernel build
**URL:** https://discourse.nixos.org/t/way-to-profide-config-file-in-cutom-kernel-build/17219
**Category:** Help
**Created:** [January 20, 2022, 8:15am UTC](https://discourse.nixos.org/t/way-to-profide-config-file-in-cutom-kernel-build/17219 "2022-01-20T08:15:44Z")
**Posts on this page:** 9
**Page:** 1
### Author:  [@pekkari](https://discourse.nixos.org/u/pekkari)
#### Post date: [January 20, 2022, 8:15am UTC](https://discourse.nixos.org/t/way-to-profide-config-file-in-cutom-kernel-build/17219/1 "2022-01-20T08:15:44Z")
Hi,
Is there any way to provide a correct .config file to build a custom kernel
in nixos? Currently I set my configuration.nix to build the latest LTS hardened
kernel by using:
```auto
[...]
boot.kernelPackages = let
linux_hardened_pkg = { fetchurl, buildLinux, ... } @ args:
buildLinux (args // rec {
version = "5.10.92-hardened1";
modDirVersion = version;
src = fetchurl {
url = "https://github.com/anthraxx/linux-hardened/archive/refs/tags/5.10.92-hardened1.tar.gz";
sha256 = "be8fab989a432906c71c13c43a120a290730df040b1e89dec14e97121506a7f3";
};
kernelPatches = [];
extraConfig = ''
'';
extraMeta.branch = "5.10";
} // (args.argsOverride or {}));
linux_hardened = pkgs.callPackage linux_hardened_pkg{};
in
pkgs.recurseIntoAttrs (pkgs.linuxPackagesFor linux_hardened);
[...]
```
And it works fine, but when I put my kernel configs in the extraConfig section I run
into a war field of errors, like failing the parse the end of file, or values that are set
and resolve to ‘n’, between other dragons.
Thanks!
---
### Author:  [@nixinator](https://discourse.nixos.org/u/nixinator)
#### Post date: [January 20, 2022, 8:23am UTC](https://discourse.nixos.org/t/way-to-profide-config-file-in-cutom-kernel-build/17219/2 "2022-01-20T08:23:50Z")
> [@The \*correct\* way to override the latest kernel config](https://discourse.nixos.org/t/the-correct-way-to-override-the-latest-kernel-config/533/9):
>
> Note that the equivalent of [structuredExtraConfig](https://github.com/NixOS/nixpkgs/blob/a74daa0ec496a1039de74075d4db093764b2a8ec/pkgs/os-specific/linux/kernel/generic.nix#L27-L28) is called [extraStructuredConfig](https://github.com/NixOS/nixpkgs/blob/a74daa0ec496a1039de74075d4db093764b2a8ec/pkgs/os-specific/linux/kernel/generic.nix#L93-L94) in kernelPatches: { lib, ... }: { boot.kernelPatches = lib.singleton { name = "enable-lirc"; patch = null; extraStructuredConfig = with lib.kernel; { LIRC = yes; }; }; }
maybe clues there?
---
### Author:  [@pekkari](https://discourse.nixos.org/u/pekkari)
#### Post date: [January 20, 2022, 8:38am UTC](https://discourse.nixos.org/t/way-to-profide-config-file-in-cutom-kernel-build/17219/3 "2022-01-20T08:38:03Z")
Looks like I have to provide all configs one by one, I’d rather ask for
sourcing the full .config file. Is it possible? I’m evaluating to port an
existing platform based in buildroot to nixos, and I want to have same
kernel with configs.
---
### Author:  [@pekkari](https://discourse.nixos.org/u/pekkari)
#### Post date: [January 20, 2022, 10:52am UTC](https://discourse.nixos.org/t/way-to-profide-config-file-in-cutom-kernel-build/17219/4 "2022-01-20T10:52:57Z")
Something like [this](https://github.com/NixOS/nixpkgs/blob/a74daa0ec496a1039de74075d4db093764b2a8ec/pkgs/os-specific/linux/kernel/generic.nix#L18) may make it, though I fail to find
further documentation how to use it. Any hints?
**Edited:** false alarm, that seems to be to modify the make target for defconfig, which is
not about generating your own file and providing it as a defconfig, so not an option.
Thanks!
---
### Author:  [@pekkari](https://discourse.nixos.org/u/pekkari)
#### Post date: [January 20, 2022, 11:18am UTC](https://discourse.nixos.org/t/way-to-profide-config-file-in-cutom-kernel-build/17219/5 "2022-01-20T11:18:10Z")
[This](https://github.com/NixOS/nixpkgs/blob/a74daa0ec496a1039de74075d4db093764b2a8ec/pkgs/os-specific/linux/kernel/manual-config.nix#L30) one it is! though I certainly don’t have any idea how to specify
a manual config for the kernel I’m looking for, any help appreciated.
---
### Author:  [@julm](https://discourse.nixos.org/u/julm)
#### Post date: [February 12, 2022, 11:49pm UTC](https://discourse.nixos.org/t/way-to-profide-config-file-in-cutom-kernel-build/17219/6 "2022-02-12T23:49:17Z")
There is a section [Customize your kernel](https://nixos.org/manual/nixos/stable/#sec-linux-config-customizing) in NixOS’ manual showing how to use `manualConfig`.
---
### Author:  [@GrabbenD](https://discourse.nixos.org/u/GrabbenD)
#### Post date: [April 29, 2023, 12:02pm UTC](https://discourse.nixos.org/t/way-to-profide-config-file-in-cutom-kernel-build/17219/7 "2023-04-29T12:02:26Z")
I’m failing to understand how to combine `buildLinux` with `manualConfig`
Did you find a solution @pekkari?
---
### Author:  [@potosi](https://discourse.nixos.org/u/potosi)
#### Post date: [July 8, 2023, 9:41pm UTC](https://discourse.nixos.org/t/way-to-profide-config-file-in-cutom-kernel-build/17219/8 "2023-07-08T21:41:27Z")
Could someone share the code to make this work on a simple configuration.nix? I’m new to nixos and have been trying to make this work for hours.
---
### Author:  [@nixinator](https://discourse.nixos.org/u/nixinator)
#### Post date: [November 8, 2023, 11:52pm UTC](https://discourse.nixos.org/t/way-to-profide-config-file-in-cutom-kernel-build/17219/9 "2023-11-08T23:52:29Z")
can you share what your to achieve, and your current code?