linux-rt_5_4: init at 5.4.61-rt37

pkgs/os-specific/linux/kernel/linux-rt-5.4.nix

@@ -0,0 +1,41 @@
+{ lib, buildLinux, fetchurl
+, kernelPatches ? [ ]
+, structuredExtraConfig ? {}
+, extraMeta ? {}
+, argsOverride ? {}
+, ... } @ args:
+
+let
+  version = "5.4.61-rt37"; # updated by ./update-rt.sh
+  branch = lib.versions.majorMinor version;
+  kversion = builtins.elemAt (lib.splitString "-" version) 0;
+in buildLinux (args // {
+  inherit version;
+
+  src = fetchurl {
+    url = "mirror://kernel/linux/kernel/v5.x/linux-${kversion}.tar.xz";
+    sha256 = "197y2yb60m1k8i7mig4pa9wsrklfxq81ba3zfahwb2b31w2kvwc6";
+  };
+
+  kernelPatches = let rt-patch = {
+    name = "rt";
+    patch = fetchurl {
+      url = "mirror://kernel/linux/kernel/projects/rt/${branch}/older/patch-${version}.patch.xz";
+      sha256 = "1qgd55x62pczgmxcxbigkg6f622ma5a6mz4gi55a8mlbxzh2pddj";
+    };
+  }; in [ rt-patch ] ++ lib.remove rt-patch kernelPatches;
+
+  structuredExtraConfig = with lib.kernel; {
+    PREEMPT_RT = yes;
+    # Fix error: unused option: PREEMPT_RT.
+    EXPERT = yes; # PREEMPT_RT depends on it (in kernel/Kconfig.preempt)
+    # Fix error: option not set correctly: PREEMPT_VOLUNTARY (wanted 'y', got 'n').
+    PREEMPT_VOLUNTARY = lib.mkForce no; # PREEMPT_RT deselects it.
+    # Fix error: unused option: RT_GROUP_SCHED.
+    RT_GROUP_SCHED = lib.mkForce (option no); # Removed by sched-disable-rt-group-sched-on-rt.patch.
+  } // structuredExtraConfig;
+
+  extraMeta = extraMeta // {
+    inherit branch;
+  };
+} // argsOverride)

pkgs/top-level/all-packages.nix

@@ -17582,6 +17582,14 @@ in
     ];
   };
 
+  linux-rt_5_4 = callPackage ../os-specific/linux/kernel/linux-rt-5.4.nix {
+    kernelPatches = [
+      kernelPatches.bridge_stp_helper
+      kernelPatches.request_key_helper
+      kernelPatches.export_kernel_fpu_functions."5.3"
+    ];
+  };
+
   linux_5_7 = callPackage ../os-specific/linux/kernel/linux-5.7.nix {
     kernelPatches = [
       kernelPatches.bridge_stp_helper
@@ -17824,12 +17832,16 @@ in
   linuxPackages_latest = linuxPackages_5_8;
   linux_latest = linuxPackages_latest.kernel;
 
-  # Build the kernel modules for the some of the kernels.
+  # Realtime kernel packages.
+  linuxPackages-rt_5_4 = linuxPackagesFor pkgs.linux-rt_5_4;
+  linuxPackages-rt = linuxPackages-rt_5_4;
+  linux-rt = linuxPackages-rt.kernel;
   linuxPackages_mptcp = linuxPackagesFor pkgs.linux_mptcp;
   linuxPackages_rpi1 = linuxPackagesFor pkgs.linux_rpi1;
   linuxPackages_rpi2 = linuxPackagesFor pkgs.linux_rpi2;
   linuxPackages_rpi3 = linuxPackagesFor pkgs.linux_rpi3;
   linuxPackages_rpi4 = linuxPackagesFor pkgs.linux_rpi4;
+  # Build kernel modules for some of the kernels.
   linuxPackages_4_4 = recurseIntoAttrs (linuxPackagesFor pkgs.linux_4_4);
   linuxPackages_4_9 = recurseIntoAttrs (linuxPackagesFor pkgs.linux_4_9);
   linuxPackages_4_14 = recurseIntoAttrs (linuxPackagesFor pkgs.linux_4_14);
@@ -17838,7 +17850,7 @@ in
   linuxPackages_5_7 = recurseIntoAttrs (linuxPackagesFor pkgs.linux_5_7);
   linuxPackages_5_8 = recurseIntoAttrs (linuxPackagesFor pkgs.linux_5_8);
 
-  # When adding to this list:
+  # When adding to the list above:
   # - Update linuxPackages_latest to the latest version
   # - Update the rev in ../os-specific/linux/kernel/linux-libre.nix to the latest one.