arch kernel update survival kit

etc_pacman.d_hooks_linux-modules-post.hook

[Trigger]
Operation = Upgrade
Type = Package
Target = linux

[Action]
Description = Restore Linux kernel modules
When = PostTransaction
Depends = coreutils
Depends = rsync
Exec = /bin/sh -xc 'KVER="${KVER:-$(uname -r)}"; if test -e "/lib/modules/backup/${KVER}"; then rsync -AHXal --ignore-existing "/lib/modules/backup/${KVER}" /lib/modules/; fi; rm -rf /lib/modules/backup'

etc_pacman.d_hooks_linux-modules-pre.hook

[Trigger]
Operation = Upgrade
Type = Package
Target = linux

[Action]
Description = Save Linux kernel modules
When = PreTransaction
Depends = rsync
Exec = /bin/sh -c 'KVER="${KVER:-$(uname -r)}"; if test -e "/lib/modules/${KVER}"; then rsync -AHXal --delete-after "/lib/mo

etc_systemd_system_linux-modules-cleanup.service

[Unit]
Description=Clean up modules from old kernels

[Service]
Type=oneshot
ExecStart=/bin/bash -exc 'for i in /usr/lib/modules/[0-9]*; do if [[ $${i##*/} = \'%v\' ]] || pacman -Qo "$${i}"; then continue; fi; rsync -AHXal "$${i}" /usr/lib/modules/.old/; rm -rf "$${i}"; done'

[Install]
WantedBy=basic.target

etc_tmpfiles.d_linux-modules-cleanup.conf

R! /usr/lib/modules/.old/* - - - 4w