diff options
Diffstat (limited to 'nixos/doc/manual/from_md/configuration/linux-kernel.chapter.xml')
| -rw-r--r-- | nixos/doc/manual/from_md/configuration/linux-kernel.chapter.xml | 121 |
1 files changed, 69 insertions, 52 deletions
diff --git a/nixos/doc/manual/from_md/configuration/linux-kernel.chapter.xml b/nixos/doc/manual/from_md/configuration/linux-kernel.chapter.xml index dd570e1d66c27..f889306d51c02 100644 --- a/nixos/doc/manual/from_md/configuration/linux-kernel.chapter.xml +++ b/nixos/doc/manual/from_md/configuration/linux-kernel.chapter.xml @@ -5,7 +5,7 @@ option <literal>boot.kernelPackages</literal>. For instance, this selects the Linux 3.10 kernel: </para> - <programlisting language="bash"> + <programlisting language="nix"> boot.kernelPackages = pkgs.linuxKernel.packages.linux_3_10; </programlisting> <para> @@ -48,7 +48,7 @@ zcat /proc/config.gz <xref linkend="sec-customising-packages" />). For instance, to enable support for the kernel debugger KGDB: </para> - <programlisting language="bash"> + <programlisting language="nix"> nixpkgs.config.packageOverrides = pkgs: pkgs.lib.recursiveUpdate pkgs { linuxKernel.kernels.linux_5_10 = pkgs.linuxKernel.kernels.linux_5_10.override { extraConfig = '' @@ -69,7 +69,7 @@ nixpkgs.config.packageOverrides = pkgs: pkgs.lib.recursiveUpdate pkgs { automatically by <literal>udev</literal>. You can force a module to be loaded via <xref linkend="opt-boot.kernelModules" />, e.g. </para> - <programlisting language="bash"> + <programlisting language="nix"> boot.kernelModules = [ "fuse" "kvm-intel" "coretemp" ]; </programlisting> <para> @@ -77,7 +77,7 @@ boot.kernelModules = [ "fuse" "kvm-intel" "coretemp&quo root file system), you can use <xref linkend="opt-boot.initrd.kernelModules" />: </para> - <programlisting language="bash"> + <programlisting language="nix"> boot.initrd.kernelModules = [ "cifs" ]; </programlisting> <para> @@ -88,7 +88,7 @@ boot.initrd.kernelModules = [ "cifs" ]; Kernel runtime parameters can be set through <xref linkend="opt-boot.kernel.sysctl" />, e.g. </para> - <programlisting language="bash"> + <programlisting language="nix"> boot.kernel.sysctl."net.ipv4.tcp_keepalive_time" = 120; </programlisting> <para> @@ -96,65 +96,82 @@ boot.kernel.sysctl."net.ipv4.tcp_keepalive_time" = 120; available parameters, run <literal>sysctl -a</literal>. </para> <section xml:id="sec-linux-config-customizing"> - <title>Customize your kernel</title> + <title>Building a custom kernel</title> <para> - The first step before compiling the kernel is to generate an - appropriate <literal>.config</literal> configuration. Either you - pass your own config via the <literal>configfile</literal> setting - of <literal>linuxKernel.manualConfig</literal>: + You can customize the default kernel configuration by overriding + the arguments for your kernel package: </para> - <programlisting language="bash"> -custom-kernel = let base_kernel = linuxKernel.kernels.linux_4_9; - in super.linuxKernel.manualConfig { - inherit (super) stdenv hostPlatform; - inherit (base_kernel) src; - version = "${base_kernel.version}-custom"; - - configfile = /home/me/my_kernel_config; - allowImportFromDerivation = true; -}; + <programlisting language="nix"> +pkgs.linux_latest.override { + ignoreConfigErrors = true; + autoModules = false; + kernelPreferBuiltin = true; + extraStructuredConfig = with lib.kernel; { + DEBUG_KERNEL = yes; + FRAME_POINTER = yes; + KGDB = yes; + KGDB_SERIAL_CONSOLE = yes; + DEBUG_INFO = yes; + }; +} </programlisting> <para> - You can edit the config with this snippet (by default - <literal>make menuconfig</literal> won't work out of the box on - nixos): + See <literal>pkgs/os-specific/linux/kernel/generic.nix</literal> + for details on how these arguments affect the generated + configuration. You can also build a custom version of Linux by + calling <literal>pkgs.buildLinux</literal> directly, which + requires the <literal>src</literal> and <literal>version</literal> + arguments to be specified. </para> - <programlisting> -nix-shell -E 'with import <nixpkgs> {}; kernelToOverride.overrideAttrs (o: {nativeBuildInputs=o.nativeBuildInputs ++ [ pkg-config ncurses ];})' + <para> + To use your custom kernel package in your NixOS configuration, set + </para> + <programlisting language="nix"> +boot.kernelPackages = pkgs.linuxPackagesFor yourCustomKernel; </programlisting> <para> - or you can let nixpkgs generate the configuration. Nixpkgs - generates it via answering the interactive kernel utility - <literal>make config</literal>. The answers depend on parameters - passed to - <literal>pkgs/os-specific/linux/kernel/generic.nix</literal> - (which you can influence by overriding - <literal>extraConfig, autoModules, modDirVersion, preferBuiltin, extraConfig</literal>). + Note that this method will use the common configuration defined in + <literal>pkgs/os-specific/linux/kernel/common-config.nix</literal>, + which is suitable for a NixOS system. </para> - <programlisting language="bash"> -mptcp93.override ({ - name="mptcp-local"; - - ignoreConfigErrors = true; - autoModules = false; - kernelPreferBuiltin = true; - - enableParallelBuilding = true; - - extraConfig = '' - DEBUG_KERNEL y - FRAME_POINTER y - KGDB y - KGDB_SERIAL_CONSOLE y - DEBUG_INFO y - ''; -}); + <para> + If you already have a generated configuration file, you can build + a kernel that uses it with + <literal>pkgs.linuxManualConfig</literal>: + </para> + <programlisting language="nix"> +let + baseKernel = pkgs.linux_latest; +in pkgs.linuxManualConfig { + inherit (baseKernel) src modDirVersion; + version = "${baseKernel.version}-custom"; + configfile = ./my_kernel_config; + allowImportFromDerivation = true; +} +</programlisting> + <note> + <para> + The build will fail if <literal>modDirVersion</literal> does not + match the source’s <literal>kernel.release</literal> file, so + <literal>modDirVersion</literal> should remain tied to + <literal>src</literal>. + </para> + </note> + <para> + To edit the <literal>.config</literal> file for Linux X.Y, proceed + as follows: + </para> + <programlisting> +$ nix-shell '<nixpkgs>' -A linuxKernel.kernels.linux_X_Y.configEnv +$ unpackPhase +$ cd linux-* +$ make nconfig </programlisting> </section> <section xml:id="sec-linux-config-developing-modules"> <title>Developing kernel modules</title> <para> - When developing kernel modules it's often convenient to run + When developing kernel modules it’s often convenient to run edit-compile-run loop as quickly as possible. See below snippet as an example of developing <literal>mellanox</literal> drivers. </para> @@ -181,7 +198,7 @@ $ make -C $dev/lib/modules/*/build M=$(pwd)/drivers/net/ethernet/mellanox module available kernel version <emphasis>that is supported by ZFS</emphasis> like this: </para> - <programlisting language="bash"> + <programlisting language="nix"> { boot.kernelPackages = pkgs.zfs.latestCompatibleLinuxPackages; } |