installkernel

#!/bin/sh
# 
# Copyright (C) 1995 - 1998, Ian A. Murdock <imurdock@debian.org>
# Copyright (C) 1998, 1999, Guy Maor
# Copyright (C) 2002, Matthew Wilcox
# Copyright (C) 2002, 2004, 2005, 2007, 2009  Clint Adams
# Copyright (C) 2009  Manoj Srivasta
# Copyright (C) 2016  Aline Freitas
#
# This script is called from /usr/src/linux/arch/i386/boot/install.sh.
# If you install it as /root/bin/installkernel, you can do a "make install"
# from a generic kernel source tree, and the image will be installed to
# the proper place for EFI system.

set -e

efi_dest=/boot/EFI/Boot
# EFI stub kernel without extension ".efi"!!
efi_file=bootx64
kernel_src=/usr/src/linux

kernversion () {
    echo $(file $1 | grep -Po '(?<=version)\W*\K[^ ]*')
}

# Parse the command line options.  Of course, powerpc has to be all
# different, and passes in a fifth argument, just because it is
# "special". We ignore the fifth argument, and do not flag is as an
# error, which it would be for any arch apart from powerpc
if [ $# -eq 3 ] || [ $# -eq 4 ] || [ $# -eq 5 ] ; then
  img="$2"
  map="$3"
  ver="$1"
  if [ $# -ge 4 ] && [ -n "$4" ] ; then
      dir="$4"
  else
      dir="/boot"
  fi
else
  echo "Usage: installkernel <version> <image> <System.map> <directory>"
  exit 1
fi

# Create backups of older versions before installing
updatever () {
  builtkernver=$(kernversion $kernel_src/$img)                                                                                                                                           
  currentkernver=$(kernversion $efi_dest/${efi_file}.efi)       

  if [[ $builtkernver != $currentkernver ]]; then                                                                                                                                           
    echo "Moving current kernel to bootx64.old.efi..."                                                                                                                                    
    mv $efi_dest/${efi_file}{,.old}.efi                                                                                                                                                       
  fi                                                                                                                                                                                        
 
  cat "$kernel_src/$img" > "$efi_dest/${efi_file}.efi"
}

updatever 

if [ $? -eq 0 ]; then
    echo "Kernel installed as ${efi_dest}/${efi_file}.efi"
fi

exit 0