{ lib, stdenv, buildPackages, runCommand, nettools, bc, bison, flex, perl, rsync, gmp, libmpc, mpfr, openssl , libelf, cpio, elfutils, zstd, python3Minimal, zlib, pahole }: let lib_ = lib; stdenv_ = stdenv; readConfig = configfile: import (runCommand "config.nix" {} '' echo "{" > "$out" while IFS='=' read key val; do [ "x''${key#CONFIG_}" != "x$key" ] || continue no_firstquote="''${val#\"}"; echo ' "'"$key"'" = "'"''${no_firstquote%\"}"'";' >> "$out" done < "${configfile}" echo "}" >> $out '').outPath; in lib.makeOverridable ({ # The kernel version version, # Position of the Linux build expression pos ? null, # Additional kernel make flags extraMakeFlags ? [], # The name of the kernel module directory # Needs to be X.Y.Z[-extra], so pad with zeros if needed. modDirVersion ? lib.versions.pad 3 version, # The kernel source (tarball, git checkout, etc.) src, # a list of { name=..., patch=..., extraConfig=...} patches kernelPatches ? [], # The kernel .config file configfile, # Manually specified nixexpr representing the config # If unspecified, this will be autodetected from the .config config ? lib.optionalAttrs allowImportFromDerivation (readConfig configfile), # Custom seed used for CONFIG_GCC_PLUGIN_RANDSTRUCT if enabled. This is # automatically extended with extra per-version and per-config values. randstructSeed ? "", # Extra meta attributes extraMeta ? {}, # for module compatibility isZen ? false, isLibre ? false, isHardened ? false, # Whether to utilize the controversial import-from-derivation feature to parse the config allowImportFromDerivation ? false, # ignored features ? null, lib ? lib_, stdenv ? stdenv_, }: let inherit (lib) hasAttr getAttr optional optionals optionalString optionalAttrs maintainers platforms; # Dependencies that are required to build kernel modules moduleBuildDependencies = [ perl libelf ] ++ optional (lib.versionAtLeast version "5.13") zstd; drvAttrs = config_: kernelConf: kernelPatches: configfile: let config = let attrName = attr: "CONFIG_" + attr; in { isSet = attr: hasAttr (attrName attr) config; getValue = attr: if config.isSet attr then getAttr (attrName attr) config else null; isYes = attr: (config.getValue attr) == "y"; isNo = attr: (config.getValue attr) == "n"; isModule = attr: (config.getValue attr) == "m"; isEnabled = attr: (config.isModule attr) || (config.isYes attr); isDisabled = attr: (!(config.isSet attr)) || (config.isNo attr); } // config_; isModular = config.isYes "MODULES"; buildDTBs = kernelConf.DTB or false; installsFirmware = (config.isEnabled "FW_LOADER") && (isModular || (config.isDisabled "FIRMWARE_IN_KERNEL")) && (lib.versionOlder version "4.14"); in (optionalAttrs isModular { outputs = [ "out" "dev" ]; }) // { passthru = rec { inherit version modDirVersion config kernelPatches configfile moduleBuildDependencies stdenv; inherit isZen isHardened isLibre; isXen = lib.warn "The isXen attribute is deprecated. All Nixpkgs kernels that support it now have Xen enabled." true; baseVersion = lib.head (lib.splitString "-rc" version); kernelOlder = lib.versionOlder baseVersion; kernelAtLeast = lib.versionAtLeast baseVersion; }; inherit src; patches = map (p: p.patch) kernelPatches # Required for deterministic builds along with some postPatch magic. ++ optional (lib.versionOlder version "5.19") ./randstruct-provide-seed.patch ++ optional (lib.versionAtLeast version "5.19") ./randstruct-provide-seed-5.19.patch # Fixes determinism by normalizing metadata for the archive of kheaders ++ optional (lib.versionAtLeast version "5.2" && lib.versionOlder version "5.4") ./gen-kheaders-metadata.patch; postPatch = '' sed -i Makefile -e 's|= depmod|= ${buildPackages.kmod}/bin/depmod|' # fixup for pre-5.4 kernels using the $(cd $foo && /bin/pwd) pattern # FIXME: remove when no longer needed substituteInPlace Makefile tools/scripts/Makefile.include --replace /bin/pwd pwd # Don't include a (random) NT_GNU_BUILD_ID, to make the build more deterministic. # This way kernels can be bit-by-bit reproducible depending on settings # (e.g. MODULE_SIG and SECURITY_LOCKDOWN_LSM need to be disabled). # See also https://kernelnewbies.org/BuildId sed -i Makefile -e 's|--build-id=[^ ]*|--build-id=none|' # Some linux-hardened patches now remove certain files in the scripts directory, so the file may not exist. [[ -f scripts/ld-version.sh ]] && patchShebangs scripts/ld-version.sh # Set randstruct seed to a deterministic but diversified value. Note: # we could have instead patched gen-random-seed.sh to take input from # the buildFlags, but that would require also patching the kernel's # toplevel Makefile to add a variable export. This would be likely to # cause future patch conflicts. for file in scripts/gen-randstruct-seed.sh scripts/gcc-plugins/gen-random-seed.sh; do if [ -f "$file" ]; then substituteInPlace "$file" \ --replace NIXOS_RANDSTRUCT_SEED \ $(echo ${randstructSeed}${src} ${placeholder "configfile"} | sha256sum | cut -d ' ' -f 1 | tr -d '\n') break fi done patchShebangs scripts # also patch arch-specific install scripts for i in $(find arch -name install.sh); do patchShebangs "$i" done ''; configurePhase = '' runHook preConfigure mkdir build export buildRoot="$(pwd)/build" echo "manual-config configurePhase buildRoot=$buildRoot pwd=$PWD" if [ -f "$buildRoot/.config" ]; then echo "Could not link $buildRoot/.config : file exists" exit 1 fi ln -sv ${configfile} $buildRoot/.config # reads the existing .config file and prompts the user for options in # the current kernel source that are not found in the file. make $makeFlags "''${makeFlagsArray[@]}" oldconfig runHook postConfigure make $makeFlags "''${makeFlagsArray[@]}" prepare actualModDirVersion="$(cat $buildRoot/include/config/kernel.release)" if [ "$actualModDirVersion" != "${modDirVersion}" ]; then echo "Error: modDirVersion ${modDirVersion} specified in the Nix expression is wrong, it should be: $actualModDirVersion" exit 1 fi # Note: we can get rid of this once http://permalink.gmane.org/gmane.linux.kbuild.devel/13800 is merged. buildFlagsArray+=("KBUILD_BUILD_TIMESTAMP=$(date -u -d @$SOURCE_DATE_EPOCH)") cd $buildRoot ''; buildFlags = [ "KBUILD_BUILD_VERSION=1-NixOS" kernelConf.target "vmlinux" # for "perf" and things like that ] ++ optional isModular "modules" ++ optionals buildDTBs ["dtbs" "DTC_FLAGS=-@"] ++ extraMakeFlags; installFlags = [ "INSTALL_PATH=$(out)" ] ++ (optional isModular "INSTALL_MOD_PATH=$(out)") ++ optional installsFirmware "INSTALL_FW_PATH=$(out)/lib/firmware" ++ optionals buildDTBs ["dtbs_install" "INSTALL_DTBS_PATH=$(out)/dtbs"]; preInstall = let # All we really need to do here is copy the final image and System.map to $out, # and use the kernel's modules_install, firmware_install, dtbs_install, etc. targets # for the rest. Easy, right? # # Unfortunately for us, the obvious way of getting the built image path, # make -s image_name, does not work correctly, because some architectures # (*cough* aarch64 *cough*) change KBUILD_IMAGE on the fly in their install targets, # so we end up attempting to install the thing we didn't actually build. # # Thankfully, there's a way out that doesn't involve just hardcoding everything. # # The kernel has an install target, which runs a pretty simple shell script # (located at scripts/install.sh or arch/$arch/boot/install.sh, depending on # which kernel version you're looking at) that tries to do something sensible. # # (it would be great to hijack this script immediately, as it has all the # information we need passed to it and we don't need it to try and be smart, # but unfortunately, the exact location of the scripts differs between kernel # versions, and they're seemingly not considered to be public API at all) # # One of the ways it tries to discover what "something sensible" actually is # is by delegating to what's supposed to be a user-provided install script # located at ~/bin/installkernel. # # (the other options are: # - a distribution-specific script at /sbin/installkernel, # which we can't really create in the sandbox easily # - an architecture-specific script at arch/$arch/boot/install.sh, # which attempts to guess _something_ and usually guesses very wrong) # # More specifically, the install script exec's into ~/bin/installkernel, if one # exists, with the following arguments: # # $1: $KERNELRELEASE - full kernel version string # $2: $KBUILD_IMAGE - the final image path # $3: System.map - path to System.map file, seemingly hardcoded everywhere # $4: $INSTALL_PATH - path to the destination directory as specified in installFlags # # $2 is exactly what we want, so hijack the script and use the knowledge given to it # by the makefile overlords for our own nefarious ends. # # Note that the makefiles specifically look in ~/bin/installkernel, and # writeShellScriptBin writes the script to /bin/installkernel, # so HOME needs to be set to just the store path. # # FIXME: figure out a less roundabout way of doing this. installkernel = buildPackages.writeShellScriptBin "installkernel" '' cp -av $2 $4 cp -av $3 $4 ''; in '' installFlagsArray+=("-j$NIX_BUILD_CORES") export HOME=${installkernel} ''; # Some image types need special install targets (e.g. uImage is installed with make uinstall) installTargets = [ (kernelConf.installTarget or ( /**/ if kernelConf.target == "uImage" then "uinstall" else if kernelConf.target == "zImage" || kernelConf.target == "Image.gz" then "zinstall" else "install")) ]; postInstall = (optionalString installsFirmware '' mkdir -p $out/lib/firmware '') + (if isModular then '' mkdir -p $dev cp vmlinux $dev/ if [ -z "''${dontStrip-}" ]; then installFlagsArray+=("INSTALL_MOD_STRIP=1") fi make modules_install $makeFlags "''${makeFlagsArray[@]}" \ $installFlags "''${installFlagsArray[@]}" unlink $out/lib/modules/${modDirVersion}/build unlink $out/lib/modules/${modDirVersion}/source mkdir -p $dev/lib/modules/${modDirVersion}/{build,source} # To save space, exclude a bunch of unneeded stuff when copying. (cd .. && rsync --archive --prune-empty-dirs \ --exclude='/build/' \ * $dev/lib/modules/${modDirVersion}/source/) cd $dev/lib/modules/${modDirVersion}/source cp $buildRoot/{.config,Module.symvers} $dev/lib/modules/${modDirVersion}/build make modules_prepare $makeFlags "''${makeFlagsArray[@]}" O=$dev/lib/modules/${modDirVersion}/build # For reproducibility, removes accidental leftovers from a `cc1` call # from a `try-run` call from the Makefile rm -f $dev/lib/modules/${modDirVersion}/build/.[0-9]*.d # Keep some extra files on some arches (powerpc, aarch64) for f in arch/powerpc/lib/crtsavres.o arch/arm64/kernel/ftrace-mod.o; do if [ -f "$buildRoot/$f" ]; then cp $buildRoot/$f $dev/lib/modules/${modDirVersion}/build/$f fi done # !!! No documentation on how much of the source tree must be kept # If/when kernel builds fail due to missing files, you can add # them here. Note that we may see packages requiring headers # from drivers/ in the future; it adds 50M to keep all of its # headers on 3.10 though. chmod u+w -R .. arch=$(cd $dev/lib/modules/${modDirVersion}/build/arch; ls) # Remove unused arches for d in $(cd arch/; ls); do if [ "$d" = "$arch" ]; then continue; fi if [ "$arch" = arm64 ] && [ "$d" = arm ]; then continue; fi rm -rf arch/$d done # Remove all driver-specific code (50M of which is headers) rm -fR drivers # Keep all headers find . -type f -name '*.h' -print0 | xargs -0 -r chmod u-w # Keep linker scripts (they are required for out-of-tree modules on aarch64) find . -type f -name '*.lds' -print0 | xargs -0 -r chmod u-w # Keep root and arch-specific Makefiles chmod u-w Makefile arch/"$arch"/Makefile* # Keep whole scripts dir chmod u-w -R scripts # Delete everything not kept find . -type f -perm -u=w -print0 | xargs -0 -r rm # Delete empty directories find -empty -type d -delete # Remove reference to kmod sed -i Makefile -e 's|= ${buildPackages.kmod}/bin/depmod|= depmod|' '' else optionalString installsFirmware '' make firmware_install $makeFlags "''${makeFlagsArray[@]}" \ $installFlags "''${installFlagsArray[@]}" ''); requiredSystemFeatures = [ "big-parallel" ]; meta = { description = "The Linux kernel" + (if kernelPatches == [] then "" else " (with patches: " + lib.concatStringsSep ", " (map (x: x.name) kernelPatches) + ")"); license = lib.licenses.gpl2Only; homepage = "https://www.kernel.org/"; maintainers = lib.teams.linux-kernel.members ++ [ maintainers.thoughtpolice ]; platforms = platforms.linux; timeout = 14400; # 4 hours } // extraMeta; }; in assert lib.versionOlder version "5.8" -> libelf != null; assert lib.versionAtLeast version "5.8" -> elfutils != null; stdenv.mkDerivation ((drvAttrs config stdenv.hostPlatform.linux-kernel kernelPatches configfile) // { pname = "linux"; inherit version; enableParallelBuilding = true; depsBuildBuild = [ buildPackages.stdenv.cc ]; nativeBuildInputs = [ perl bc nettools openssl rsync gmp libmpc mpfr zstd python3Minimal ] ++ optional (stdenv.hostPlatform.linux-kernel.target == "uImage") buildPackages.ubootTools ++ optional (lib.versionOlder version "5.8") libelf # Removed util-linuxMinimal since it should not be a dependency. ++ optionals (lib.versionAtLeast version "4.16") [ bison flex ] ++ optionals (lib.versionAtLeast version "5.2") [ cpio pahole zlib ] ++ optional (lib.versionAtLeast version "5.8") elfutils ; hardeningDisable = [ "bindnow" "format" "fortify" "stackprotector" "pic" "pie" ]; # Absolute paths for compilers avoid any PATH-clobbering issues. makeFlags = [ "O=$(buildRoot)" "CC=${stdenv.cc}/bin/${stdenv.cc.targetPrefix}cc" "HOSTCC=${buildPackages.stdenv.cc}/bin/${buildPackages.stdenv.cc.targetPrefix}cc" "HOSTLD=${buildPackages.stdenv.cc.bintools}/bin/${buildPackages.stdenv.cc.targetPrefix}ld" "ARCH=${stdenv.hostPlatform.linuxArch}" ] ++ lib.optionals (stdenv.hostPlatform != stdenv.buildPlatform) [ "CROSS_COMPILE=${stdenv.cc.targetPrefix}" ] ++ (stdenv.hostPlatform.linux-kernel.makeFlags or []) ++ extraMakeFlags; karch = stdenv.hostPlatform.linuxArch; } // (optionalAttrs (pos != null) { inherit pos; })))