Keeping your Kernel up to date on Gentoo can be a bit daunting, especially when you are running the “keyworded” Kernel, meaning not the stable version, but the “always latest” version by keyword ~amd64. There’s a new version almost every week and updating it manually can be quite annoying over time. At least it felt for me …
1 2 3 4 | make make modules make modules_install make install |
Then after that, updating the grub config … And what was the command to update the Kernel dependent modules again? Oh ya …
1 | emerge @module-rebuild |
For some reason, I can never remember that one … Don’t ask me why.
So, I came up with a little helper in form of a bash script that does pretty much all the work for me, all I have to do is tell it which Kernel version I want to have and it does all the magic for me. All I need to do from time to time is to clean up old Kernel installations.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 | #!/bin/bash selected_kernel="" kernel_base_directory="/usr/src/" kernel_directory="" usage() { printf "Usage: $0 -k=[<selected_kernel>]\n" printf "Usage: $0 --kernel=[<selected_kernel>]\n" printf "Usage: $0 --latest\n\n" printf "<selected_kernel> is the full kernel version string.\n" printf "If the '--latest' (without the quotation marks) option is used, the latest available kernel version will be compiled.\n\n" printf "Available kernel versions (current active version is marked with an asterisk):\n`eselect kernel list`\n" 1>&2; exit 1; } for i in "$@"; do case $i in -k=*|--kernel=*) selected_kernel="${i#*=}" shift ;; --latest) selected_kernel=$(eselect kernel list | tail -1 | awk '{print $2}' | sed 's/[][]//g') ;; -*|--*) echo "Unknown option $i" exit 1 ;; *) usage ;; esac done # if no kernel is selected, show help text if [ -z "${selected_kernel}" ] ; then usage fi #set the new kernel directory kernel_directory="${kernel_base_directory}${selected_kernel}" # compiling new kernel compile_new_kernel() { echo "New Kernel Version: ${selected_kernel}" echo "Entering kernel directory: ${kernel_directory}"; cd ${kernel_directory} echo "Copying kernel configuration"; cp /usr/src/linux/.config . echo "Switching symlink to new kernel"; eselect kernel set ${selected_kernel} echo "Applying config via 'make olddefconfig'"; make olddefconfig echo "Building new kernel"; make -j12 echo "Building modules"; make modules echo "Installing modules"; make modules_install echo "Installing new kernel"; make install echo "Configuring grub2"; cp /boot/grub/grub.cfg /boot/grub/grub.cfg.bak GRUB_USE_LINUX_LABEL=true grub-mkconfig -o /boot/grub/grub.cfg echo "Re-compile kernel dependant modules"; emerge -av @module-rebuild echo "Kernel update complete. You may restart your computer now." echo "Feel free to run 'eclean-kernel -n 2' to cleanup old kernel files but keep the latest 2." } if [ -d ${kernel_directory} ] ; then current_kernel_version=$(uname -r) if [ ${selected_kernel} == "linux-${current_kernel_version}" ] ; then echo "You are currently running this kernel version." echo "Exiting!"; exit; else compile_new_kernel fi else echo "Error: Directory ${kernel_directory} does not exist." echo "Exiting!"; exit; fi |
Save this as /usr/bin/kernel-update, make sure it is executable via chmod +x /usr/bin/kernel-update and all you have to do to switch to your desired Kernel version is (Example: latest installed Kernel):
1 | kernel-update --latest |
If you want a specific version, first check which versions are available vis eselect kernel list and take the version string for a Kernel as the argument. For example to build linux-5.17.7-gentoo:
1 | kernel-update -k=linux-5.17.7-gentoo |
If you like this script, let me know. I am always open to improvements, so feel free to suggest them!