#!/bin/sh

default=0
timeout=5
verbose=0

conf=/boot/extlinux.conf
myconf=/etc/update-extlinux.conf

# read in extlinux settings
if [ -f "$myconf" ]; then
	. $myconf
fi

everbose() {
	if [ "$verbose" = "0" ]; then
		return
	fi

	echo $*
}

ewarn() {
	echo "WARNING:" $@ >&2
}

eerror() {
	echo "ERROR:" $@ >&2
	return 1
}

everbose "Updating extlinux configuration."

if [ "x$root" = "x" ]; then
	ewarn "Root device is not specified in $myconf."
	blkid_export=$(blkid -o export /dev/root)
	if [ -n "$blkid_export" ]; then
		export $blkid_export
	fi
	if [ -z "$UUID" ]; then
		# try parse /proc/mount for mounted /
		dev=$(awk '$2 == "/" {dev=$1} END {print dev}' /proc/mounts)
		if [ -n "$dev" ]; then
			blkid_export=$(blkid -o export $dev)
			if [ -n "$blkid_export" ]; then
				export "$blkid_export"
			fi
		fi
	fi
	if [ -z "$UUID" ]; then
		if [ -z "$dev" ]; then
			eerror "Failed to detect root device"
			exit 1
		else
			root=$dev
		fi
	else
		root=UUID=$UUID
	fi
	everbose "Root device is: $root"
fi

everbose "Installing mboot.c32 to /boot."
cp /usr/share/syslinux/mboot.c32 /boot

everbose "Installing menu.c32 to /boot."
cp /usr/share/syslinux/menu.c32 /boot

rtimeout=$((${timeout}\*10))
syslinux_menu=menu.c32
menu_hidden=

# vesa menu has been requested?
if [ "$vesa_menu" = "1" ]; then
	syslinux_menu=vesamenu.c32
fi

everbose "Installing $syslinux_menu to /boot."
cp /usr/share/syslinux/vesamenu.c32 /boot

echo "# Generated by update-extlinux" > $conf.new
echo "DEFAULT $syslinux_menu" >> $conf.new
echo "PROMPT 0" >> $conf.new
echo "MENU TITLE Alpine/$(uname -s) Boot Menu" >> $conf.new
if [ "$hidden" = "1" ]; then
	echo "MENU HIDDEN" >> $conf.new
fi
echo "MENU AUTOBOOT Alpine will be booted automatically in # seconds." >> $conf.new
echo "TIMEOUT $rtimeout" >> $conf.new

lst=0
if [ -f "/boot/xen.gz" ]; then
	for kernel in $(find /boot -name vmlinuz-* -type f); do
		tag=$(basename $kernel | cut -b9-)
		everbose "Found Xen hypervisor: /boot/xen.gz, kernel: $kernel"

		if [ -f "/boot/initramfs-$tag" ]; then
			everbose "Found initramfs: /boot/initramfs-$tag"
			initramfs="initramfs-$tag"
		fi

		echo "LABEL $lst" >> $conf.new
		if [ "$lst" = "$default" ]; then
			echo "  MENU DEFAULT" >> $conf.new
		fi
		echo "  MENU LABEL Xen + Linux $tag" >> $conf.new
		echo "  KERNEL mboot.c32" >> $conf.new
		echo "  APPEND xen.gz $xen_opts --- $(basename $kernel) root=$root modules=${modules}${TYPE:+,$TYPE} $default_kernel_opts --- $initramfs" >> $conf.new
		echo "" >> $conf.new
		lst=$(($lst + 1))
	done
fi

for kernel in $(find /boot -name vmlinuz-* -type f); do
	tag=$(basename $kernel | cut -b9-)
	everbose "Found kernel: $kernel"

	if [ -f "/boot/initramfs-$tag" ]; then
		everbose "Found initramfs: /boot/initramfs-$tag"
		initramfs="initrd=initramfs-$tag"
	fi
	label=$(grep -w -l $tag /usr/share/kernel/*/kernel.release | cut -d/ -f5)
	if [ -z "$label" ]; then
		label=$lst
	fi
	echo "LABEL $label" >> $conf.new
	if [ "$label" = "$default" ]; then
		echo "  MENU DEFAULT" >> $conf.new
	fi
	echo "  MENU LABEL Linux $tag" >> $conf.new
	echo "  KERNEL $(basename $kernel)" >> $conf.new
	echo "  APPEND $initramfs root=$root modules=${modules}${TYPE:+,$TYPE} $default_kernel_opts" >> $conf.new
	echo "" >> $conf.new
	lst=$(($lst + 1))
done

if [ -f "/boot/memtest" ]; then
	everbose "Found memtest86+: /boot/memtest"
	echo "LABEL memtest" >> $conf.new
	echo "  MENU LABEL Memtest86+" >> $conf.new
        echo "  KERNEL memtest" >> $conf.new
	echo "" >> $conf.new
	lst=$(($lst + 1))
fi

everbose "$lst entries found."

for entry in /etc/update-extlinux.d/*; do
	[ -f "$entry" ] && cat $entry >> $conf.new
done

if [ "$overwrite" = "1" ]; then
	# keep a backup just in case
	if [ -f "$conf" ]; then
		mv $conf $conf.old
	fi

	mv $conf.new $conf
fi