nixpkgs/pkgs/os-specific/linux/kernel/manual-config.nix
Bernardo Meurer ea167e8ccb
buildLinux: take and propagate extraMakeFlags
This is just for practicity, as it allows users of buildLinux to pass
along extra flags they need in the kernel's make invocation. This makes,
for example, supporting LLVM _much_ easier, and could enable us in the
future to provide clang-built kernels.
2021-07-12 10:39:52 -07:00

336 lines
13 KiB
Nix

{ lib, buildPackages, runCommand, nettools, bc, bison, flex, perl, rsync, gmp, libmpc, mpfr, openssl
, libelf, cpio, elfutils, zstd, gawk, python3Minimal
, writeTextFile
}:
let
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 "}" >> $out
'').outPath;
in {
lib,
# Allow overriding stdenv on each buildLinux call
stdenv,
# The kernel version
version,
# Additional kernel make flags
extraMakeFlags ? [],
# The version of the kernel module directory
modDirVersion ? version,
# The kernel source (tarball, git checkout, etc.)
src,
# a list of { name=..., patch=..., extraConfig=...} patches
kernelPatches ? [],
# The kernel .config file
configfile,
# Manually specified nixexpr representing the config
# If unspecified, this will be autodetected from the .config
config ? lib.optionalAttrs allowImportFromDerivation (readConfig configfile),
# Custom seed used for CONFIG_GCC_PLUGIN_RANDSTRUCT if enabled. This is
# automatically extended with extra per-version and per-config values.
randstructSeed ? "",
# Use defaultMeta // extraMeta
extraMeta ? {},
# for module compatibility
isZen ? false,
isLibre ? false,
isHardened ? false,
# Whether to utilize the controversial import-from-derivation feature to parse the config
allowImportFromDerivation ? false,
# ignored
features ? null,
}:
let
inherit (lib)
hasAttr getAttr optional optionals optionalString optionalAttrs maintainers platforms;
# Dependencies that are required to build kernel modules
moduleBuildDependencies = optional (lib.versionAtLeast version "4.14") libelf;
installkernel = writeTextFile { name = "installkernel"; executable=true; text = ''
#!${stdenv.shell} -e
mkdir -p $4
cp -av $2 $4
cp -av $3 $4
''; };
commonMakeFlags = [
"O=$(buildRoot)"
] ++ lib.optionals (stdenv.hostPlatform.linux-kernel ? makeFlags)
stdenv.hostPlatform.linux-kernel.makeFlags;
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";
installsFirmware = (config.isEnabled "FW_LOADER") &&
(isModular || (config.isDisabled "FIRMWARE_IN_KERNEL")) &&
(lib.versionOlder version "4.14");
in (optionalAttrs isModular { outputs = [ "out" "dev" ]; }) // {
passthru = {
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;
kernelOlder = lib.versionOlder version;
kernelAtLeast = lib.versionAtLeast version;
};
inherit src;
patches =
map (p: p.patch) kernelPatches
# Required for deterministic builds along with some postPatch magic.
++ optional (lib.versionAtLeast version "4.13") ./randstruct-provide-seed.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;
prePatch = ''
for mf in $(find -name Makefile -o -name Makefile.include -o -name install.sh); do
echo "stripping FHS paths in \`$mf'..."
sed -i "$mf" -e 's|/usr/bin/||g ; s|/bin/||g ; s|/sbin/||g'
done
sed -i Makefile -e 's|= depmod|= ${buildPackages.kmod}/bin/depmod|'
# 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|'
patchShebangs scripts
'';
postPatch = ''
# 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.
if [ -f scripts/gcc-plugins/gen-random-seed.sh ]; then
substituteInPlace scripts/gcc-plugins/gen-random-seed.sh \
--replace NIXOS_RANDSTRUCT_SEED \
$(echo ${randstructSeed}${src} ${configfile} | sha256sum | cut -d ' ' -f 1 | tr -d '\n')
fi
'';
configurePhase = ''
runHook preConfigure
mkdir build
export buildRoot="$(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 $buildRoot
'';
buildFlags = [
"KBUILD_BUILD_VERSION=1-NixOS"
kernelConf.target
"vmlinux" # for "perf" and things like that
]
++ optional isModular "modules"
++ extraMakeFlags;
installFlags = [
"INSTALLKERNEL=${installkernel}"
"INSTALL_PATH=$(out)"
] ++ (optional isModular "INSTALL_MOD_PATH=$(out)")
++ optional installsFirmware "INSTALL_FW_PATH=$(out)/lib/firmware";
preInstall = ''
installFlagsArray+=("-j$NIX_BUILD_CORES")
'';
# 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 (kernelConf.DTB or false) then ''
make $makeFlags "''${makeFlagsArray[@]}" dtbs dtbs_install INSTALL_DTBS_PATH=$out/dtbs
'' else "") + (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
chmod u-w 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/";
repositories.git = "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git";
maintainers = [
maintainers.thoughtpolice
];
platforms = platforms.linux;
timeout = 14400; # 4 hours
} // extraMeta;
};
in
assert (lib.versionAtLeast version "4.14" && 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 gawk zstd python3Minimal ]
++ optional (stdenv.hostPlatform.linux-kernel.target == "uImage") buildPackages.ubootTools
++ optional (lib.versionAtLeast version "4.14" && lib.versionOlder version "5.8") libelf
# Removed util-linuxMinimal since it should not be a dependency.
++ optionals (lib.versionAtLeast version "4.16") [ bison flex ]
++ optional (lib.versionAtLeast version "5.2") cpio
++ optional (lib.versionAtLeast version "5.8") elfutils
;
hardeningDisable = [ "bindnow" "format" "fortify" "stackprotector" "pic" "pie" ];
# Absolute paths for compilers avoid any PATH-clobbering issues.
makeFlags = commonMakeFlags ++ [
"CC=${stdenv.cc}/bin/${stdenv.cc.targetPrefix}cc"
"HOSTCC=${buildPackages.stdenv.cc}/bin/${buildPackages.stdenv.cc.targetPrefix}cc"
"ARCH=${stdenv.hostPlatform.linuxArch}"
] ++ lib.optional (stdenv.hostPlatform != stdenv.buildPlatform) [
"CROSS_COMPILE=${stdenv.cc.targetPrefix}"
] ++ extraMakeFlags;
karch = stdenv.hostPlatform.linuxArch;
})