#!/bin/sh

# umbrelOS USB installer image
INSTALLER=https://download.umbrel.com/release/1.1.2/umbrelos-amd64-usb-installer.img.xz

# use CentOS' kernel/initrd to make bootable CD
VMLINUZ=http://ftp.jaist.ac.jp/pub/Linux/CentOS-stream/9-stream/BaseOS/x86_64/os/isolinux/vmlinuz
INITRD=http://ftp.jaist.ac.jp/pub/Linux/CentOS-stream/9-stream/BaseOS/x86_64/os/isolinux/initrd.img

# isolinux
ISOLINUX_BIN=http://ftp.jaist.ac.jp/pub/Linux/CentOS-stream/9-stream/BaseOS/x86_64/os/isolinux/isolinux.bin
LDLINUX_C32=http://ftp.jaist.ac.jp/pub/Linux/CentOS-stream/9-stream/BaseOS/x86_64/os/isolinux/ldlinux.c32

# output image
ISO_OUTPUT=output.iso

# work directory
WORKDIR=./work
LIVEOS_DIR=$WORKDIR/LiveOS
BOOT_DIR=$WORKDIR/boot
ISOLINUX_ISO_DIR=isolinux
ISOLINUX_DIR=$WORKDIR/$ISOLINUX_ISO_DIR

# setup directory
rm -rf $WORKDIR
mkdir -p $LIVEOS_DIR
mkdir -p $BOOT_DIR
mkdir -p $ISOLINUX_DIR

# settle contents
wget -P $BOOT_DIR $VMLINUZ
wget -P $BOOT_DIR $INITRD
wget -P $ISOLINUX_DIR $ISOLINUX_BIN
wget -P $ISOLINUX_DIR $LDLINUX_C32

cat - << EOS > $ISOLINUX_DIR/isolinux.cfg
default boot
label boot
	kernel ../boot/vmlinuz
	initrd ../boot/initrd.img
	append root=live:CDLABEL=linux rd.live.image
EOS

# create squashfs.img
LOOP_DEV=`/sbin/losetup -f`
LOOP_PART=${LOOP_DEV}p2
INSTALLER_FILE_XZ=`echo $INSTALLER | sed 's/\// /g' | awk '{print $NF}'`
INSTALLER_FILE=`echo $INSTALLER_FILE_XZ | sed 's/\.xz//'`

rm -rf $INSTALLER_FILE $INSTALLER_FILE_XZ
wget $INSTALLER
xz -d $INSTALLER_FILE_XZ

sudo /sbin/losetup -P $LOOP_DEV $INSTALLER_FILE
sudo mount $LOOP_PART /mnt
sudo mksquashfs /mnt $LIVEOS_DIR/squashfs.img
sudo umount /mnt
sudo /sbin/losetup -d $LOOP_DEV

# create ISO image
rm -rf $ISO_OUTPUT
mkisofs -o $ISO_OUTPUT -R -J -V linux -b $ISOLINUX_ISO_DIR/isolinux.bin -c $ISOLINUX_ISO_DIR/boot.cat -no-emul-boot -boot-load-size 4 -boot-info-table $WORKDIR