Merge pull request #129806 from lovesegfault/kernel-extra-build-flags

linux: groundwork to enable LLVM/LTO builds

pkgs/os-specific/linux/kernel/generate-config.pl

@@ -19,6 +19,7 @@ my $autoModules = $ENV{'AUTO_MODULES'};
 my $preferBuiltin = $ENV{'PREFER_BUILTIN'};
 my $ignoreConfigErrors = $ENV{'ignoreConfigErrors'};
 my $buildRoot = $ENV{'BUILD_ROOT'};
+my $makeFlags = $ENV{'MAKE_FLAGS'};
 $SIG{PIPE} = 'IGNORE';
 
 # Read the answers.
@@ -40,7 +41,7 @@ close ANSWERS;
 sub runConfig {
 
     # Run `make config'.
-    my $pid = open2(\*IN, \*OUT, "make -C $ENV{SRC} O=$buildRoot config SHELL=bash ARCH=$ENV{ARCH} CC=$ENV{CC} HOSTCC=$ENV{HOSTCC} HOSTCXX=$ENV{HOSTCXX}");
+    my $pid = open2(\*IN, \*OUT, "make -C $ENV{SRC} O=$buildRoot config SHELL=bash ARCH=$ENV{ARCH} CC=$ENV{CC} HOSTCC=$ENV{HOSTCC} HOSTCXX=$ENV{HOSTCXX} $makeFlags");
 
     # Parse the output, look for questions and then send an
     # appropriate answer.

pkgs/os-specific/linux/kernel/generic.nix

@@ -21,6 +21,9 @@
 , # Legacy overrides to the intermediate kernel config, as string
   extraConfig ? ""
 
+  # Additional make flags passed to kbuild
+, extraMakeFlags ? []
+
 , # kernel intermediate config overrides, as a set
  structuredExtraConfig ? {}
 
@@ -97,7 +100,7 @@ let
     in lib.concatStringsSep "\n" ([baseConfigStr] ++ configFromPatches);
 
   configfile = stdenv.mkDerivation {
-    inherit ignoreConfigErrors autoModules preferBuiltin kernelArch;
+    inherit ignoreConfigErrors autoModules preferBuiltin kernelArch extraMakeFlags;
     pname = "linux-config";
     inherit version;
 
@@ -116,6 +119,9 @@ let
     # e.g. "bzImage"
     kernelTarget = stdenv.hostPlatform.linux-kernel.target;
 
+    makeFlags = lib.optionals (stdenv.hostPlatform.linux-kernel ? makeFlags) stdenv.hostPlatform.linux-kernel.makeFlags
+      ++ extraMakeFlags;
+
     prePatch = kernel.prePatch + ''
       # Patch kconfig to print "###" after every question so that
       # generate-config.pl from the generic builder can answer them.
@@ -134,16 +140,19 @@ let
       export HOSTLD=$LD_FOR_BUILD
 
       # Get a basic config file for later refinement with $generateConfig.
-      make -C . O="$buildRoot" $kernelBaseConfig \
+      make $makeFlags \
+          -C . O="$buildRoot" $kernelBaseConfig \
           ARCH=$kernelArch \
           HOSTCC=$HOSTCC HOSTCXX=$HOSTCXX HOSTAR=$HOSTAR HOSTLD=$HOSTLD \
-          CC=$CC OBJCOPY=$OBJCOPY OBJDUMP=$OBJDUMP READELF=$READELF
+          CC=$CC OBJCOPY=$OBJCOPY OBJDUMP=$OBJDUMP READELF=$READELF \
+          $makeFlags
 
       # Create the config file.
       echo "generating kernel configuration..."
       ln -s "$kernelConfigPath" "$buildRoot/kernel-config"
       DEBUG=1 ARCH=$kernelArch KERNEL_CONFIG="$buildRoot/kernel-config" AUTO_MODULES=$autoModules \
-           PREFER_BUILTIN=$preferBuiltin BUILD_ROOT="$buildRoot" SRC=. perl -w $generateConfig
+        PREFER_BUILTIN=$preferBuiltin BUILD_ROOT="$buildRoot" SRC=. MAKE_FLAGS="$makeFlags" \
+        perl -w $generateConfig
     '';
 
     installPhase = "mv $buildRoot/.config $out";
@@ -151,7 +160,6 @@ let
     enableParallelBuilding = true;
 
     passthru = rec {
-
       module = import ../../../../nixos/modules/system/boot/kernel_config.nix;
       # used also in apache
       # { modules = [ { options = res.options; config = svc.config or svc; } ];
@@ -172,14 +180,14 @@ let
   }; # end of configfile derivation
 
   kernel = (callPackage ./manual-config.nix {}) {
-    inherit version modDirVersion src kernelPatches randstructSeed lib stdenv extraMeta configfile;
+    inherit version modDirVersion src kernelPatches randstructSeed lib stdenv extraMakeFlags extraMeta configfile;
 
     config = { CONFIG_MODULES = "y"; CONFIG_FW_LOADER = "m"; };
   };
 
   passthru = {
     features = kernelFeatures;
-    inherit commonStructuredConfig isZen isHardened isLibre modDirVersion;
+    inherit commonStructuredConfig structuredExtraConfig extraMakeFlags isZen isHardened isLibre modDirVersion;
     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;

pkgs/os-specific/linux/kernel/manual-config.nix

@@ -1,5 +1,5 @@
 { lib, buildPackages, runCommand, nettools, bc, bison, flex, perl, rsync, gmp, libmpc, mpfr, openssl
-, libelf, cpio, elfutils, zstd, gawk
+, libelf, cpio, elfutils, zstd, gawk, python3Minimal
 , writeTextFile
 }:
 
@@ -19,6 +19,8 @@ in {
   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.)
@@ -121,7 +123,7 @@ let
         # See also https://kernelnewbies.org/BuildId
         sed -i Makefile -e 's|--build-id=[^ ]*|--build-id=none|'
 
-        patchShebangs scripts/ld-version.sh
+        patchShebangs scripts
       '';
 
       postPatch = ''
@@ -173,7 +175,9 @@ let
         "KBUILD_BUILD_VERSION=1-NixOS"
         kernelConf.target
         "vmlinux"  # for "perf" and things like that
-      ] ++ optional isModular "modules";
+      ]
+      ++ optional isModular "modules"
+      ++ extraMakeFlags;
 
       installFlags = [
         "INSTALLKERNEL=${installkernel}"
@@ -307,7 +311,7 @@ stdenv.mkDerivation ((drvAttrs config stdenv.hostPlatform.linux-kernel kernelPat
   enableParallelBuilding = true;
 
   depsBuildBuild = [ buildPackages.stdenv.cc ];
-  nativeBuildInputs = [ perl bc nettools openssl rsync gmp libmpc mpfr gawk zstd ]
+  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.
@@ -325,7 +329,7 @@ stdenv.mkDerivation ((drvAttrs config stdenv.hostPlatform.linux-kernel kernelPat
     "ARCH=${stdenv.hostPlatform.linuxArch}"
   ] ++ lib.optional (stdenv.hostPlatform != stdenv.buildPlatform) [
     "CROSS_COMPILE=${stdenv.cc.targetPrefix}"
-  ];
+  ] ++ extraMakeFlags;
 
   karch = stdenv.hostPlatform.linuxArch;
 })