#!/bin/sh

# Copyright (C) 2006  Joey Hess  <joeyh@debian.org>
# Copyright (C) 2006, 2007, 2008  Martin Michlmayr <tbm@cyrius.com>

# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301,
# USA.

set -e

error() {
	echo "$@" >&2
	exit 1
}

check_mtd() {
	if [ ! -e /proc/mtd ]; then
		error "/proc/mtd doesn't exist"
	fi
}

mtdblock() {
	grep "\"$1\"" /proc/mtd | cut -d: -f 1 | sed 's/mtd/\/dev\/mtdblock/'
}

check_dev_mtdblock() {
	if [ ! -b "$1" ]; then
		error "$1 is not a block device"
	fi
}

mtdsize() {
	size=$(grep "\"$1\"" /proc/mtd | cut -d " " -f 2)
	printf "%d" 0x$size
}

check_subarch() {
	if [ -n "$subarch" ] && [ "$subarch" != "$1" ]; then
		echo "Kernel $kfile does not match your subarchitecture" >&2
		echo "$1, therefore not writing it to flash." >&2
		exit 0
	fi
}

check_size() {
	if [ $2 -gt $3 ]; then
		error "The $1 doesn't fit in flash."
	fi
}

# See http://www.nslu2-linux.org/wiki/Info/BootFlash -- the NSLU2 uses a
# 16 byte MTD header, the first four bytes (big endian) give the length of
# the remainder of the image, and the remaining bytes are zero.  Generate
# this header.
sercomm_header() {
	perl -e 'print pack("N4", shift)' "$1"
}

nslu2_swap() {
	if [ "$little_endian" ]; then
		devio "<<"$1 "xp $,4"
	else
		cat $1
	fi
}

machine=$(grep "^Hardware" /proc/cpuinfo | sed 's/Hardware\s*:\s*//')

if [ "x$1" = "x--supported" ]; then
	case "$machine" in
		"Buffalo Linkstation Pro/Live")		exit 0 ;;
		"Buffalo/Revogear Kurobox Pro")		exit 0 ;;
		"D-Link DNS-323")			exit 0 ;;
		"GLAN Tank")				exit 0 ;;
		"HP Media Vault mv2120")		exit 0 ;;
		"Linksys NSLU2")			exit 0 ;;
		"QNAP TS-109/TS-209" | "QNAP TS-409")	exit 0 ;;
		"Thecus N2100")				exit 0 ;;
		*)					exit 1 ;;
	esac
fi

if [ -n "$1" ]; then
	kvers="$1"
	kfile=/boot/vmlinuz-$kvers
	ifile=/boot/initrd.img-$kvers
	desc="Debian kernel $1"
	idesc="Debian ramdisk $1"
else
	if [ -e /vmlinuz ]; then
		kfile=/vmlinuz
		ifile=/initrd.img
	elif [ -e /boot/vmlinuz ]; then
		kfile=/boot/vmlinuz
		ifile=/boot/initrd.img
	else
		error "Cannot find a default kernel in /vmlinuz or /boot/vmlinuz"
	fi
	desc="Debian kernel"
	idesc="Debian ramdisk"
fi

if [ ! -e $kfile ] || [ ! -e $ifile ]; then
	error "Can't find $kfile and $ifile"
fi
kfilesize=$(wc -c $kfile | awk '{print $1}')
ifilesize=$(wc -c $ifile | awk '{print $1}')

# Extract the subarchitecture from the kernel name
if [ -L "$kfile" ]; then
	kfile=$(readlink -e "$kfile")
fi
subarch=$(echo "$kfile" | sed -e 's/.*-//')

case "$machine" in
	"Buffalo Linkstation Pro/Live" | "Buffalo/Revogear Kurobox Pro")
		check_subarch "orion5x"
		tmp=$(tempfile)
		printf "Generating kernel u-boot image... " >&2
		case "$machine" in
			"Buffalo Linkstation Pro/Live")
				# Set machine id 1585 (0x0631)
				devio > $tmp 'wl 0xe3a01c06,4' 'wl 0xe3811031,4'
			;;
			"Buffalo/Revogear Kurobox Pro")
				# Set machine id 1509 (0x05e5)
				devio > $tmp 'wl 0xe3a01c05,4' 'wl 0xe38110e5,4'
			;;
		esac
		cat $kfile >> $tmp
		mkimage -A arm -O linux -T kernel -C none -a 0x00008000 \
			-e 0x00008000 -n "$desc" -d $tmp $tmp.uboot >&2 1>/dev/null
		echo "done." >&2
		if [ -e /boot/uImage.buffalo ]; then
			echo "Creating backup of /boot/uImage.buffalo." >&2
			mv /boot/uImage.buffalo /boot/uImage.buffalo.bak
		fi
		echo "Creating new /boot/uImage.buffalo." >&2
		mv $tmp.uboot /boot/uImage.buffalo
		rm -f $tmp
		printf "Generating initrd u-boot image... " >&2
		mkimage -A arm -O linux -T ramdisk -C gzip -a 0x0 \
			-e 0x0 -n "$idesc" -d $ifile $tmp.uboot >&2 1>/dev/null
		echo "done." >&2
		if [ -e /boot/initrd.buffalo ]; then
			echo "Creating backup of /boot/initrd.buffalo." >&2
			mv /boot/initrd.buffalo /boot/initrd.buffalo.bak
		fi
		echo "Creating new /boot/initrd.buffalo." >&2
		mv $tmp.uboot /boot/initrd.buffalo
	;;
	"D-Link DNS-323")
		check_subarch "orion5x"
		check_mtd
		imtd=$(mtdblock "File System")
		if [ -z "$imtd" ]; then
			error "Cannot find mtd partition 'File System'"
		fi
		check_dev_mtdblock "$imtd"
		imtdsize=$(mtdsize "File System")
		check_size "File System" $((ifilesize + 64)) $imtdsize
		kmtd=$(mtdblock "Linux Kernel")
		if [ -z "$kmtd" ]; then
			error "Cannot find mtd partition 'Linux Kernel'"
		fi
		check_dev_mtdblock "$kmtd"
		kmtdsize=$(mtdsize "Linux Kernel")
		check_size "Linux Kernel" $(($kfilesize + 8 + 64)) $kmtdsize
		printf "Generating kernel u-boot image... " >&2
		tmp=$(tempfile)
		# Set machine id 1542 (0x0606)
		devio > $tmp 'wl 0xe3a01c06,4' 'wl 0xe3811006,4'
		cat $kfile >> $tmp
		mkimage -A arm -O linux -T kernel -C none -a 0x00008000 \
			-e 0x00008000 -n "$desc" -d $tmp $tmp.uboot >&2 1>/dev/null
		echo "done." >&2
		printf "Flashing kernel... " >&2
		cat $tmp.uboot > $kmtd || error "failed."
		echo "done." >&2
		rm -f $tmp.uboot $tmp
		printf "Generating initramfs u-boot image... " >&2
		mkimage -A arm -O linux -T ramdisk -C gzip -a 0x00800000 \
			-e 0x00800000 -n "$idesc" -d $ifile $tmp.uboot >&2 1>/dev/null
		printf "Flashing initramfs... " >&2
		cat $tmp.uboot > $imtd || error "failed."
		echo "done." >&2
		rm -f $tmp.uboot
	;;
	"GLAN Tank")
		rm -f /boot/initrd /boot/zImage
		ln -s $(basename $ifile) /boot/initrd
		(
			# Set machine id 1100 (0x044c)
			devio 'wl 0xe3a01c04,4' 'wl 0xe381104c,4'
			cat $kfile
		) > /boot/zImage
	;;
	"HP Media Vault mv2120")
		check_subarch "orion5x"
		tmp=$(tempfile)
		printf "Generating kernel u-boot image... " >&2
		# Set machine id 1693 (0x069d)
		devio > $tmp 'wl 0xe3a01c06,4' 'wl 0xe381109d,4'
		cat $kfile >> $tmp
		mkimage -A arm -O linux -T multi -C none -n "$desc" -a 0x01000000 \
			-e 0x01000000 -d $tmp:$ifile $tmp.uboot >&2 1>/dev/null
		echo "done." >&2
		if [ -e /boot/uImage ]; then
			echo "Creating backup of /boot/uImage." >&2
			mv /boot/uImage /boot/uImage.bak
		fi
		echo "Creating new /boot/uImage." >&2
		mv $tmp.uboot /boot/uImage
		rm -f $tmp
	;;
	"Linksys NSLU2")
		check_subarch "ixp4xx"
		case "$(dpkg --print-architecture)" in
			arm|armel)
				little_endian=1
			;;
			armeb)
				little_endian=0
			;;
		esac
		check_mtd
		fismtd=$(mtdblock "FIS directory")
		if [ -z "$fismtd" ]; then
			error "Cannot find mtd FIS directory"
		fi
		kmtd=$(mtdblock Kernel)
		if [ -z "$kmtd" ]; then
			error "Cannot find mtd partition 'Kernel'"
		fi
		check_dev_mtdblock "$kmtd"
		kmtdsize=$(mtdsize "Kernel")
		check_size "kernel" $(($kfilesize + 16 + 16)) $kmtdsize
		imtd=$(mtdblock Ramdisk)
		if [ -z "$imtd" ]; then
			error "Cannot find mtd partition 'Ramdisk'"
		fi
		check_dev_mtdblock "$imtd"
		imtdsize=$(mtdsize "Ramdisk")
		check_size "ramdisk" $(($ifilesize + 16)) $imtdsize
		# The following devio magic parses the FIS directory to
		# obtain the size, offset and name of each partition.  This
		# used used to obtain the offset of the Kernel partition.
		offset=$(echo "$(devio "<<$fismtd" '
			<= $ 0x20000 -
			L= 0x1000
			$( 1
				# 0xff byte in name[0] ends the partition table
				$? @ 255 =
				# output size base name
				<= f15+
				.= b 0xfffffff &
				<= f4+
				.= b
				pf "%lu %lu "
				<= f28-
				cp 16
				pn
				<= f240+
				L= L256-
			$) L255>')" |
			while read a b c; do
				if [ "$c" = "Kernel" ]; then
					echo $b
				fi
			done)
		# The Kernel partition, starting at $offset, is divided into
		# two areas at $boundary.  We therefore need to split the
		# kernel into two and write them to flash with two Sercomm
		# headers.
		boundary=1441792 # 0x00160000
		ksize1=$(expr $boundary - $offset - 16)
		tmp=$(tempfile)
		printf "Flashing kernel: " >&2
		(
			sercomm_header $(expr $kfilesize + 16)
			dd if=$kfile of=$tmp bs=$ksize1 count=1 2>/dev/null
			nslu2_swap $tmp
			sercomm_header 131072
			dd if=$kfile of=$tmp ibs=$ksize1 skip=1 2>/dev/null
			nslu2_swap $tmp
			rm -f $tmp
		) > "$kmtd" || error "failed."
		echo "done." >&2
		printf "Flashing initramfs: " >&2
		dd if=$ifile of=$tmp ibs=$(($imtdsize - 16)) conv=sync 2>/dev/null
		(
			sercomm_header $ifilesize
			nslu2_swap $tmp
			rm -f $tmp
		) > $imtd || error "failed."
		echo "done." >&2
	;;
	"QNAP TS-109/TS-209" | "QNAP TS-409")
		check_subarch "orion5x"
		check_mtd
		imtd=$(mtdblock "RootFS1")
		if [ -z "$imtd" ]; then
			error "Cannot find mtd partition 'RootFS1'"
		fi
		check_dev_mtdblock "$imtd"
		imtdsize=$(mtdsize "RootFS1")
		check_size "RootFS1" $ifilesize $imtdsize
		kmtd=$(mtdblock Kernel)
		if [ -z "$kmtd" ]; then
			error "Cannot find mtd partition 'Kernel'"
		fi
		check_dev_mtdblock "$kmtd"
		kmtdsize=$(mtdsize "Kernel")
		check_size "Kernel" $(($kfilesize + 8 + 64)) $kmtdsize
		printf "Generating kernel u-boot image... " >&2
		tmp=$(tempfile)
		case "$machine" in
			"QNAP TS-109/TS-209")
				# Set machine id 1565 (0x061d)
				devio > $tmp 'wl 0xe3a01c06,4' 'wl 0xe381101d,4'
			;;
			"QNAP TS-409")
				# Set machine id 1601 (0x0641)
				devio > $tmp 'wl 0xe3a01c06,4' 'wl 0xe3811041,4'
			;;
		esac
		cat $kfile >> $tmp
		mkimage -A arm -O linux -T kernel -C none -a 0x00008000 \
			-e 0x00008000 -n "$desc" -d $tmp $tmp.uboot >&2 1>/dev/null
		echo "done." >&2
		printf "Flashing kernel... " >&2
		cat $tmp.uboot > $kmtd || error "failed."
		echo "done." >&2
		rm -f $tmp.uboot $tmp
		printf "Flashing initramfs... " >&2
		pad=$(expr $imtdsize - $ifilesize)
		(
			cat $ifile
			dd if=/dev/zero bs=$pad count=1 2>/dev/null
		) > $imtd || error "failed."
		echo "done." >&2
	;;
	"Thecus N2100")
		check_subarch "iop32x"
		check_mtd
		imtd=$(mtdblock ramdisk)
		if [ -z "$imtd" ]; then
			error "Cannot find mtd partition 'ramdisk'"
		fi
		check_dev_mtdblock "$imtd"
		imtdsize=$(mtdsize "ramdisk")
		check_size "ramdisk" $ifilesize $imtdsize
		kmtd=$(mtdblock kernel)
		if [ -z "$kmtd" ]; then
			error "Cannot find mtd partition 'kernel'"
		fi
		check_dev_mtdblock "$kmtd"
		kmtdsize=$(mtdsize "kernel")
		check_size "kernel" $(($kfilesize + 8)) $kmtdsize
		printf "Flashing kernel... " >&2
		(
			# Set machine id 1101 (0x044d)
			devio 'wl 0xe3a01c04,4' 'wl 0xe381104d,4'
			cat $kfile
		) > $kmtd || error "failed."
		echo "done." >&2
		printf "Flashing initramfs... " >&2
		pad=$(expr $imtdsize - $ifilesize)
		(
			cat $ifile
			dd if=/dev/zero bs=$pad count=1 2>/dev/null
		) > $imtd || error "failed."
		echo "done." >&2
	;;
	*)
		error "Unsupported platform."
	;;
esac

