diff options
Diffstat (limited to 'nixpkgs/nixos/modules/system/boot/kernel.nix')
| -rw-r--r-- | nixpkgs/nixos/modules/system/boot/kernel.nix | 325 |
1 files changed, 325 insertions, 0 deletions
diff --git a/nixpkgs/nixos/modules/system/boot/kernel.nix b/nixpkgs/nixos/modules/system/boot/kernel.nix new file mode 100644 index 00000000000..6edb9082e75 --- /dev/null +++ b/nixpkgs/nixos/modules/system/boot/kernel.nix @@ -0,0 +1,325 @@ +{ config, lib, pkgs, ... }: + +with lib; + +let + + inherit (config.boot) kernelPatches; + inherit (config.boot.kernel) features randstructSeed; + inherit (config.boot.kernelPackages) kernel; + + kernelModulesConf = pkgs.writeText "nixos.conf" + '' + ${concatStringsSep "\n" config.boot.kernelModules} + ''; + +in + +{ + + ###### interface + + options = { + + boot.kernel.features = mkOption { + default = {}; + example = literalExample "{ debug = true; }"; + internal = true; + description = '' + This option allows to enable or disable certain kernel features. + It's not API, because it's about kernel feature sets, that + make sense for specific use cases. Mostly along with programs, + which would have separate nixos options. + `grep features pkgs/os-specific/linux/kernel/common-config.nix` + ''; + }; + + boot.kernelPackages = mkOption { + default = pkgs.linuxPackages; + type = types.unspecified // { merge = mergeEqualOption; }; + apply = kernelPackages: kernelPackages.extend (self: super: { + kernel = super.kernel.override { + inherit randstructSeed; + kernelPatches = super.kernel.kernelPatches ++ kernelPatches; + features = lib.recursiveUpdate super.kernel.features features; + }; + }); + # We don't want to evaluate all of linuxPackages for the manual + # - some of it might not even evaluate correctly. + defaultText = "pkgs.linuxPackages"; + example = literalExample "pkgs.linuxPackages_2_6_25"; + description = '' + This option allows you to override the Linux kernel used by + NixOS. Since things like external kernel module packages are + tied to the kernel you're using, it also overrides those. + This option is a function that takes Nixpkgs as an argument + (as a convenience), and returns an attribute set containing at + the very least an attribute <varname>kernel</varname>. + Additional attributes may be needed depending on your + configuration. For instance, if you use the NVIDIA X driver, + then it also needs to contain an attribute + <varname>nvidia_x11</varname>. + ''; + }; + + boot.kernelPatches = mkOption { + type = types.listOf types.attrs; + default = []; + example = literalExample "[ pkgs.kernelPatches.ubuntu_fan_4_4 ]"; + description = "A list of additional patches to apply to the kernel."; + }; + + boot.kernel.randstructSeed = mkOption { + type = types.str; + default = ""; + example = "my secret seed"; + description = '' + Provides a custom seed for the <varname>RANDSTRUCT</varname> security + option of the Linux kernel. Note that <varname>RANDSTRUCT</varname> is + only enabled in NixOS hardened kernels. Using a custom seed requires + building the kernel and dependent packages locally, since this + customization happens at build time. + ''; + }; + + boot.kernelParams = mkOption { + type = types.listOf types.str; + default = [ ]; + description = "Parameters added to the kernel command line."; + }; + + boot.consoleLogLevel = mkOption { + type = types.int; + default = 4; + description = '' + The kernel console <literal>loglevel</literal>. All Kernel Messages with a log level smaller + than this setting will be printed to the console. + ''; + }; + + boot.vesa = mkOption { + type = types.bool; + default = false; + description = '' + Whether to activate VESA video mode on boot. + ''; + }; + + boot.extraModulePackages = mkOption { + type = types.listOf types.package; + default = []; + example = literalExample "[ config.boot.kernelPackages.nvidia_x11 ]"; + description = "A list of additional packages supplying kernel modules."; + }; + + boot.kernelModules = mkOption { + type = types.listOf types.str; + default = []; + description = '' + The set of kernel modules to be loaded in the second stage of + the boot process. Note that modules that are needed to + mount the root file system should be added to + <option>boot.initrd.availableKernelModules</option> or + <option>boot.initrd.kernelModules</option>. + ''; + }; + + boot.initrd.availableKernelModules = mkOption { + type = types.listOf types.str; + default = []; + example = [ "sata_nv" "ext3" ]; + description = '' + The set of kernel modules in the initial ramdisk used during the + boot process. This set must include all modules necessary for + mounting the root device. That is, it should include modules + for the physical device (e.g., SCSI drivers) and for the file + system (e.g., ext3). The set specified here is automatically + closed under the module dependency relation, i.e., all + dependencies of the modules list here are included + automatically. The modules listed here are available in the + initrd, but are only loaded on demand (e.g., the ext3 module is + loaded automatically when an ext3 filesystem is mounted, and + modules for PCI devices are loaded when they match the PCI ID + of a device in your system). To force a module to be loaded, + include it in <option>boot.initrd.kernelModules</option>. + ''; + }; + + boot.initrd.kernelModules = mkOption { + type = types.listOf types.str; + default = []; + description = "List of modules that are always loaded by the initrd."; + }; + + system.modulesTree = mkOption { + type = types.listOf types.path; + internal = true; + default = []; + description = '' + Tree of kernel modules. This includes the kernel, plus modules + built outside of the kernel. Combine these into a single tree of + symlinks because modprobe only supports one directory. + ''; + # Convert the list of path to only one path. + apply = pkgs.aggregateModules; + }; + + system.requiredKernelConfig = mkOption { + default = []; + example = literalExample '' + with config.lib.kernelConfig; [ + (isYes "MODULES") + (isEnabled "FB_CON_DECOR") + (isEnabled "BLK_DEV_INITRD") + ] + ''; + internal = true; + type = types.listOf types.attrs; + description = '' + This option allows modules to specify the kernel config options that + must be set (or unset) for the module to work. Please use the + lib.kernelConfig functions to build list elements. + ''; + }; + + }; + + + ###### implementation + + config = mkIf (!config.boot.isContainer) { + + system.build = { inherit kernel; }; + + system.modulesTree = [ kernel ] ++ config.boot.extraModulePackages; + + # Implement consoleLogLevel both in early boot and using sysctl + # (so you don't need to reboot to have changes take effect). + boot.kernelParams = + [ "loglevel=${toString config.boot.consoleLogLevel}" ] ++ + optionals config.boot.vesa [ "vga=0x317" "nomodeset" ]; + + boot.kernel.sysctl."kernel.printk" = mkDefault config.boot.consoleLogLevel; + + boot.kernelModules = [ "loop" "atkbd" ]; + + boot.initrd.availableKernelModules = + [ # Note: most of these (especially the SATA/PATA modules) + # shouldn't be included by default since nixos-generate-config + # detects them, but I'm keeping them for now for backwards + # compatibility. + + # Some SATA/PATA stuff. + "ahci" + "sata_nv" + "sata_via" + "sata_sis" + "sata_uli" + "ata_piix" + "pata_marvell" + + # Standard SCSI stuff. + "sd_mod" + "sr_mod" + + # SD cards and internal eMMC drives. + "mmc_block" + + # Support USB keyboards, in case the boot fails and we only have + # a USB keyboard, or for LUKS passphrase prompt. + "uhci_hcd" + "ehci_hcd" + "ehci_pci" + "ohci_hcd" + "ohci_pci" + "xhci_hcd" + "xhci_pci" + "usbhid" + "hid_generic" "hid_lenovo" "hid_apple" "hid_roccat" + "hid_logitech_hidpp" "hid_logitech_dj" + + ] ++ optionals (pkgs.stdenv.isi686 || pkgs.stdenv.isx86_64) [ + # Misc. x86 keyboard stuff. + "pcips2" "atkbd" "i8042" + + # x86 RTC needed by the stage 2 init script. + "rtc_cmos" + ]; + + boot.initrd.kernelModules = + [ # For LVM. + "dm_mod" + ]; + + # The Linux kernel >= 2.6.27 provides firmware. + hardware.firmware = [ kernel ]; + + # Create /etc/modules-load.d/nixos.conf, which is read by + # systemd-modules-load.service to load required kernel modules. + environment.etc = + { "modules-load.d/nixos.conf".source = kernelModulesConf; + }; + + systemd.services.systemd-modules-load = + { wantedBy = [ "multi-user.target" ]; + restartTriggers = [ kernelModulesConf ]; + serviceConfig = + { # Ignore failed module loads. Typically some of the + # modules in ‘boot.kernelModules’ are "nice to have but + # not required" (e.g. acpi-cpufreq), so we don't want to + # barf on those. + SuccessExitStatus = "0 1"; + }; + }; + + lib.kernelConfig = { + isYes = option: { + assertion = config: config.isYes option; + message = "CONFIG_${option} is not yes!"; + configLine = "CONFIG_${option}=y"; + }; + + isNo = option: { + assertion = config: config.isNo option; + message = "CONFIG_${option} is not no!"; + configLine = "CONFIG_${option}=n"; + }; + + isModule = option: { + assertion = config: config.isModule option; + message = "CONFIG_${option} is not built as a module!"; + configLine = "CONFIG_${option}=m"; + }; + + ### Usually you will just want to use these two + # True if yes or module + isEnabled = option: { + assertion = config: config.isEnabled option; + message = "CONFIG_${option} is not enabled!"; + configLine = "CONFIG_${option}=y"; + }; + + # True if no or omitted + isDisabled = option: { + assertion = config: config.isDisabled option; + message = "CONFIG_${option} is not disabled!"; + configLine = "CONFIG_${option}=n"; + }; + }; + + # The config options that all modules can depend upon + system.requiredKernelConfig = with config.lib.kernelConfig; [ + # !!! Should this really be needed? + (isYes "MODULES") + (isYes "BINFMT_ELF") + ] ++ (optional (randstructSeed != "") (isYes "GCC_PLUGIN_RANDSTRUCT")); + + # nixpkgs kernels are assumed to have all required features + assertions = if config.boot.kernelPackages.kernel ? features then [] else + let cfg = config.boot.kernelPackages.kernel.config; in map (attrs: + { assertion = attrs.assertion cfg; inherit (attrs) message; } + ) config.system.requiredKernelConfig; + + }; + +} |