Export kernel source

Author: tschaffter

README.md

@@ -89,10 +89,10 @@ to include today's date to the value of `--kernel-localversion`. The value of
     sudo reboot
     sestatus
 
-After installing the above kernel, its name will be:
+After installing the above kernel, its version will be:
 
-    $ uname -a
-    Linux raspberrypi 5.4.51-20200804-hardened+ #1 SMP Sun Jun 14 15:06:51 UTC 2020 armv7l GNU/Linux
+    $ uname -r
+    5.4.51-20200804-hardened+
 
 **Note:** The builder inside the docker container runs as a non-root user. The command
 `mkdir output` included in the above command ensures that the builder will be able
@@ -104,6 +104,25 @@ Copy the Debian packages `*.deb` generated to the target Raspbery Pi, for exampl
 using `scp`. Then follow the instructions given at the end of the command used to
 build the kernel (see above).
 
+- `linux-headers`: The kernel headers, required when compiling any code that
+  interfaces with the kernel.
+- `linux-image`: The kernel image and the associated modules.
+- `linux-libc-dev`: Linux support headers for userspace development.
+
+### Install the kernel source
+
+You can also install the kernel source in case you need it to compile a module
+for the kernel in the future (e.g. for )
+
+1. Copy the archive `linux-source-<version>.tar.xz` to the Pi.
+2. Extract the archive in `/usr/src/`.
+
+        tar -xf linux-source-<version>.tar.xz
+
+3. Create the symbolic link `/usr/src/linux` to the folder extracted.
+
+        ln -s /usr/src/linux /usr/src/linux-source-<version>.tar.xz
+
 ## Update the kernel
 
 Repeat the same protocol as given above to build and install a newer version of

build-kernel.sh

@@ -224,6 +224,12 @@ ls -al
 echo "Moving .deb packages to $_output_dir"
 mv $_workdir/*.deb /output
 
+echo "Compressing linux source to $_output_dir"
+mv linux linux-source-${_kernel_version}-${_arg_kernel_localversion}+
+tar cJf \
+	$_output_dir/linux-source-${_kernel_version}-${_arg_kernel_localversion}+.tar.xz \
+	linux-source-${_kernel_version}-${_arg_kernel_localversion}+
+
 
 echo "SUCCESS The kernel has been successfully packaged."
 echo ""