#!/bin/sh

# Copyright 2019, 2023  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.

cd $(dirname $0) ; CWD=$(pwd)

# This script repacks initrd.gz and usbboot.img from an existing tree in
# $TMP/build-slackware-installer/package-slackware-installer/*-installer-filesystem
# to allow making some changes to the installer files and then testing them.

INSTALLERVERSION=${INSTALLERVERSION:-"15.0"}
EFIBOOT=${EFIBOOT:-1}
TMP=${TMP:-/tmp}

# Automatically determine the architecture we're building on:
if [ -z "$ARCH" ]; then
  case "$(uname -m)" in
    i?86) ARCH=i686
      SLACKROOT=${SLACKROOT:-/root/slackware-current}
      OUTPUT=${OUTPUT:-$TMP/output-ia32-$(basename $(uname -r))}
      ;;
    x86_64) ARCH=x86_64
      SLACKROOT=${SLACKROOT:-/root/slackware64-current}
      OUTPUT=${OUTPUT:-$TMP/output-x86_64-$(uname -r)}
      ;;
    arm*) readelf /usr/bin/file -A | grep -E -q "Tag_CPU.*[4,5]" && ARCH=arm || ARCH=armv7hl
      SLACKROOT=${SLACKROOT:-/root/slackware-current}
      OUTPUT=${OUTPUT:-$TMP/output-arm-$(uname -r)}
      ;;
    # Unless $ARCH is already set, use uname -m for all other archs:
    *) ARCH=$(uname -m)
      SLACKROOT=${SLACKROOT:-/root/slackware-current}
      OUTPUT=${OUTPUT:-$TMP/output-$(uname -m)-$(uname -r)}
      ;;
  esac
  export ARCH
fi

NUMJOBS=${NUMJOBS:-" -j7 "}

mkdir -p $OUTPUT
( cd $TMP/build-slackware-installer/package-slackware-installer/*-installer-filesystem
  # CREATE INITRD.GZ:
  # Determine the size of the installer:
  echo "    Installer size (uncompressed): $( du -sh . )"
  find . | cpio -o -H newc | xz -9fv -C crc32 > $OUTPUT/initrd.img
  echo "    New installer image is ${OUTPUT}/initrd.img"

  # CREATE USBBOOT.IMG:
  # Like initrd.img, the usbboot.img will be created in the current directory
  echo "--- Creating an image for the USB boot disk ---"

  # Calculate sizes:
  let USBIMG=$( LC_ALL=C du -ck ${OUTPUT}/initrd*.img | grep total | cut -f1 )
  for KERN in ${SLACKROOT}/kernels/*.?/*zImage ; do
    let USBIMG=USBIMG+$( LC_ALL=C du -sk $KERN | cut -f1 )
  done
  let USBIMG=USBIMG+777  # Add just that little extra...

  if [ $EFIBOOT -eq 1 ]; then
    # A bit more extra space since elilo will be added...
    let USBIMG=USBIMG+256
  fi

  # Generate a pxelinux.cfg/default file (used for usbboot.img too)
  cat ${SLACKROOT}/isolinux/isolinux.cfg \
    | sed -e "s#/kernels/#kernels/#" > ${OUTPUT}/pxelinux.cfg_default

  # Create a DOS formatted image file
  if $(which mkfs.msdos 1>/dev/null 2>&1) ; then
    MKDOS=mkfs.msdos
  else
    MKDOS=mkdosfs
  fi
  rm -f ${OUTPUT}/usbboot.img
  ${MKDOS} -n USBSLACK -F 16 -C ${OUTPUT}/usbboot.img $USBIMG || exit 1
  file ${OUTPUT}/usbboot.img

  # Copy all relevant files into the image.
  rm -rf ${OUTPUT}/usbmount
  mkdir -p -m700 ${OUTPUT}/usbmount
  mount -o loop,rw ${OUTPUT}/usbboot.img ${OUTPUT}/usbmount
  echo "--- Copying data to the USB boot disk image: ---"
  cp $SLACKROOT/isolinux/setpkg ${OUTPUT}/usbmount/
  cp $SLACKROOT/isolinux/{f*.txt,message.txt} ${OUTPUT}/usbmount/
  cp ${OUTPUT}/initrd*.img ${OUTPUT}/usbmount/
  cat ${OUTPUT}/pxelinux.cfg_default |sed -e 's# kernels/# #g' -e 's#/.zImage##' \
    -e 's#/memtest##' \
    > ${OUTPUT}/usbmount/syslinux.cfg

  # Add EFI support:
  if [ $EFIBOOT -eq 1 ]; then
    cp -a ${SLACKROOT}/source/installer/sources/efi.${ARCH}/* ${OUTPUT}/usbmount
    # Make sure the Slackware and kernel version in message.txt are up to date:
    cat ${SLACKROOT}/source/installer/sources/efi.${ARCH}/EFI/BOOT/message.txt | sed "s/version.*/version ${INSTALLERVERSION} \(Linux kernel $(uname -r | cut -f 1 -d -)\)\!/g" > ${OUTPUT}/usbmount/EFI/BOOT/message.txt
  fi

  # Older syslinux can not cope with subdirectories - let's just be safe:
  echo "--- Making the usbboot image bootable: ---"
  (
    cd $SLACKROOT/kernels/
    for dir in `find  -type d -name "*.?" -maxdepth 1` ; do
      cp $dir/*zImage ${OUTPUT}/usbmount/$dir
    done
    cp $SLACKROOT/kernels/memtest/memtest ${OUTPUT}/usbmount/memtest
  )
  sync

  # Stamp the file with the syslinux bootloader:
  #   > Do "vi ~/.mtoolsrc" to add "mtools_skip_check=1",
  #   > if the next command gives an error:
  umount ${OUTPUT}/usbmount
  syslinux ${OUTPUT}/usbboot.img

  # Clean up:
  rm -rf ${OUTPUT}/usbmount
  
)