update re4son-kernel for Raspberry Pi 2/3

update.sh

#!/bin/bash

# Installs/updates re4son-kernel for Raspberry Pi 2/3
# see: https://re4son-kernel.com/re4son-pi-kernel/

x="/usr/local/src"
rm -rf "${x:?}"/*

wget -O "$x"/re4son-kernel_current.tar.xz https://re4son-kernel.com/download/re4son-kernel-current/
tar -xJf "$x"/re4son-kernel_current.tar.xz -C "$x"

if [ -e "$x"/re4son-kernel_current.tar.xz ]; then
  rm -rf "$x"/re4son-kernel_current.tar.xz
fi

boot_dir='/dev/mmcblk0p1'
if [ "$(df -P /boot | tail -1 | cut -d' ' -f 1)" = "$boot_dir" ]; then
  echo "$boot_dir is already mounted @ /boot/."
else
  mount "$boot_dir" /boot/
fi

cd "$x"/re4son-kernel_*

./install.sh