#!/bin/bash

# Copyright 2019, 2024  Patrick J. Volkerding, Sebeka, Minnesota, USA
# All rights reserved.
#
# Redistribution and use of this script, with or without modification, is
# permitted provided that the following conditions are met:
#
# 1. Redistributions of this script must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
#
#  THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
#  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
#  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO
#  EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
#  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
#  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
#  OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
#  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
#  OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
#  ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

# This is a simple script to generate an initial ramdisk when a new
# kernel is installed. If the kernel is vmlinuz-6.11.5, it will generate
# initrd-6.11.5.img. If there's a symlink pointing at the kernel (for
# example, vmlinuz-generic), it will also make a matching initrd-generic.img
# symlink. Finally, it also supports a plain initrd.gz symlink to the initrd,
# which might still be needed by some old setups.

# To generate an initrd automatically, just run "geninitrd".
# Which kernel will be used follows this priority:
# If a kernel was provided on the command line:
# geninitrd /boot/vmlinuz-6.12.1
# Then we will use that kernel.
# Otherwise, if the KERNEL environment variable was provided:
# KERNEL=/boot/vmlinuz-6.12.1 geninitrd
# Then we will use that kernel.
# Otherwise we will use the value for KERNEL defined in /etc/default/geninitrd.
# If KERNEL remains undefined after loading /etc/default/geninitrd, then
# we will fall back on using the newest kernel we find in /boot.

# If you use an encrypted root, you may need an appropriate /etc/mkinitrd.conf
# (if you will be setting GENERATOR=mkinitrd in /etc/default/geninitrd), or you
# could try using GENERATOR=dracut.

cd $(dirname $0)/../..

# Was KERNEL already defined? If so, save it as a possible override:
if [ ! -z "$KERNEL" ]; then
  KERNEL_OVERRIDE=$KERNEL
fi

# Was a kernel given on the command line? If so, this is the highest priority
# for the kernel to use:
if [ ! -z "$1" ]; then
  KERNEL_OVERRIDE=$1
fi

# Load default options:
if [ -r etc/default/geninitrd ]; then
  . etc/default/geninitrd
fi

# If we have a KERNEL_OVERRIDE use it for the KERNEL:
if [ ! -z "$KERNEL_OVERRIDE" ]; then
  KERNEL=$KERNEL_OVERRIDE
  unset KERNEL_OVERRIDE
fi

if [ ! -z "$KERNEL" ]; then
  export KERNEL
fi

# In case you cannot make this script do exactly what you require, you're
# welcome to create your own script to be run instead. Define this in
# /etc/default/geninitrd (GENINITRD_OVERRIDE_SCRIPT).
if [ ! -z $GENINITRD_OVERRIDE_SCRIPT ]; then
  # If this is an absolute pathname, make it relative to /:
  RELATIVE_OVERRIDE_SCRIPT=$GENINITRD_OVERRIDE_SCRIPT
  if [ "$(echo $RELATIVE_OVERRIDE_SCRIPT | cut -b 1)" = "/" ]; then
    RELATIVE_OVERRIDE_SCRIPT="$(echo $RELATIVE_OVERRIDE_SCRIPT | cut -b 2-)"
  fi
fi
if [ -x "$RELATIVE_OVERRIDE_SCRIPT" ]; then
  chroot . $GENINITRD_OVERRIDE_SCRIPT
else # we will run the default handler from the setup scripts:
  chroot . /var/lib/pkgtools/setup/setup.01.mkinitrd
fi