Add enter-kernel-dev tool

5 files changed, 87 insertions, 4 deletions

diff --git a/.gitignore b/.gitignore
index 92b2793..9a899cc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 .direnv
+/result
diff --git a/flake.nix b/flake.nix
index f2431dc..8eb47d7 100644
--- a/flake.nix
+++ b/flake.nix
@@ -29,7 +29,9 @@
         pkgs = nixpkgs.legacyPackages."${system}";
 
         # A set of scripts to simplify kernel development.
-        kernelDevTools = pkgs.callPackage ./tools.nix { };
+        kernelDevTools = pkgs.callPackage ./tools.nix {
+          flakeSelf = self.outPath;
+        };
 
         linuxCommonDependencies = [
           kernelDevTools
@@ -106,6 +108,12 @@
           ];
       in
       {
+        packages = {
+          default = kernelDevTools;
+
+          inherit kernelDevTools;
+        };
+
         devShells = {
           default = self.devShells."${system}".linux_6_8;
 
diff --git a/tools.nix b/tools.nix
index 5f90e27..2c942ff 100644
--- a/tools.nix
+++ b/tools.nix
@@ -1,9 +1,13 @@
-{ stdenvNoCC }:
+{ stdenvNoCC, makeWrapper, flakeSelf }:
 stdenvNoCC.mkDerivation {
   name = "kernel-dev-tools";
 
   src = ./tools;
-  
+
+  nativeBuildInputs = [
+    makeWrapper
+  ];
+
   dontConfigure = true;
   dontBuild = true;
 
@@ -16,6 +20,9 @@ stdenvNoCC.mkDerivation {
       install -m0555 "$script" $out/bin/
     done
 
+    wrapProgram $out/bin/enter-kernel-dev \
+      --set FLAKE_DIR "${flakeSelf}"
+
     runHook preInstall
   '';
 }
diff --git a/tools/enter-kernel-dev b/tools/enter-kernel-dev
new file mode 100755
index 0000000..ffd16ed
--- /dev/null
+++ b/tools/enter-kernel-dev
@@ -0,0 +1,67 @@
+#!/usr/bin/env bash
+
+set -e
+
+SCRIPT_DIR=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
+
+# When this script is used as is, SCRIPT_DIR is ok. If it's used as
+# part of kernelDevTools, we have to inject the path to the flake.
+if [ -z "$FLAKE_DIR" ]; then
+   FLAKE_DIR="$SCRIPT_DIR"
+fi
+
+gcc_flag=false
+
+# Parse command-line options
+TEMP=$(getopt -o '' --longoptions gcc -- "$@")
+eval set -- "$TEMP"
+
+# Extract options into variables
+while true; do
+    case "$1" in
+	--gcc)
+	    gcc_flag=true
+	    shift
+	    ;;
+	--)
+	    shift
+	    break
+	    ;;
+	*)
+	    echo "Error: Invalid option"
+	    echo "Usage: $0 [--gcc]"
+	    exit 1
+	    ;;
+    esac
+done
+
+OLDEST_VERSION=$(git tag --contains=HEAD | grep -oE 'v[0-9]+\.[0-9]+' | sort | head -n1)
+
+if [ -z "$OLDEST_VERSION" ]; then
+    tput bold
+    echo -n "Failed to recognize kernel version."
+    tput sgr0
+    echo " This could have different reasons:"
+    echo
+    echo "1. This is not a Git checkout of the Linux kernel sources. To checkout Linux, try:"
+    echo "   \$ linux-checkout linux-src"
+    echo
+    echo "2. The repository has no remote that contains the version tags. Try:"
+    echo "   \$ git remote add stable git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
+    echo "   \$ git fetch stable"
+    exit 1
+fi
+
+ATTRIBUTE="linux_$(echo "$OLDEST_VERSION" | tr -d 'v' | tr '.' '_')"
+
+if $gcc_flag; then
+    ATTRIBUTE=${ATTRIBUTE}_gcc
+fi
+
+echo -n "Entering environment "
+tput bold
+echo -n "$ATTRIBUTE"
+tput sgr0			# reset
+echo ". This might take a moment. Exit via ^D."
+
+exec nix develop "$FLAKE_DIR"\#"$ATTRIBUTE" --command "$SHELL"
diff --git a/tools/linux-checkout b/tools/linux-checkout
index 7069f07..7097ad3 100644..100755
--- a/tools/linux-checkout
+++ b/tools/linux-checkout
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/usr/bin/env bash
 
 set -eu