#! /bin/bash
#
# Sheeva kernel install
# This README can be used to flash the new kernel
# Watch out for erase/flash errors
# If errors are encountered you should redo the flash
#
# This is a mainline Linux Kernel and you must set
# the mainlineLinux and arcNumber env variables in U-Boot
# and change the bootargs for a successful boot.
#
# setenv mainlineLinux yes
# setenv arcNumber 2097
####### change bootargs, replace nand_mtd with orion_nand and add rootfstype=jffs2
# setenv bootargs rootfstype=jffs2 console=ttyS0,115200 mtdparts=orion_nand:0x400000@0x100000(uImage),0x1fb00000@0x500000(rootfs) rw root=/dev/mtdblock1 rw ip=192.168.1.9:192.168.1.4:192.168.1.4:255.255.255.0:DB88FXX81:eth0:none
# saveenv

####### change vm security settings
# Due to changes in vm security a change must be made in /etc/sysctl.d/10-process-security.conf.
# vm.mmap_min_addr should be set to 32768 (This change is safe for any kernel version).
# If this is not done it is likely that you will not be able to login remotely.
# Although you should still be able to login as root on the main console.

set -e
set -u

KVer='2.6.34'

function Md5Compare ()
{
	if [[ $(cat $2 | cut -d' ' -f1) \
			!= $(md5sum $1 | cut -d' ' -f1) ]]; then
		echo "Bad md5 detected on $1"
		exit 1
	fi
}

function Download()
{
	echo "Downloading files"
	local f=''
	for f in Modules.tar.gz Modules.tar.gz.md5 uImage uImage.md5 System.map; do
		if [[ ! -f sheeva-$KVer-$f ]]; then
			if [[ -z "$(which wget)" ]]; then
				echo "Use apt-get to install wget, then rerun this script"
				exit 1
			fi
			local sites="http://www.plugapps.com/with-linux http://sheeva.with-linux.com/sheeva"
			local s=''
			for s in $sites; do
				if wget -c $s/$KVer/sheeva-$KVer-$f; then
					break
				fi
			done
			if [[ ! -f sheeva-$KVer-$f ]]; then
				echo "Unable to retrieve sheeva-$KVer-$f"
				exit 1
			fi
		fi
	done
	Md5Compare sheeva-$KVer-Modules.tar.gz sheeva-$KVer-Modules.tar.gz.md5
	Md5Compare sheeva-$KVer-uImage sheeva-$KVer-uImage.md5
}

function CheckSize()
{
	local uImageFile=sheeva-$KVer-uImage
	local mtd=$(grep uImage /proc/mtd | cut -d' ' -f1 | sed 's#:##')
	local mtdHexSize=$(grep uImage /proc/mtd | cut -d' ' -f2)
	local mtdSize=''
	let mtdSize=0x$mtdHexSize
	local uImageSize=$(stat -c%s "$uImageFile")
	if (( uImageSize > mtdSize )); then
		echo "uImage size $uImageSize exceeds $mtd size $mtdSize"
		echo "You must resize your mtds before this kernel will fit!"
		echo "The simplest way to do this is with the SheevaPlug installer"
		exit 1
	fi
}

function ExtractModules()
{
	echo "Extracting modules"
	tar x -C / --overwrite -zf sheeva-$KVer-Modules.tar.gz
	[[ -d /boot ]] || mkdir /boot
	cp sheeva-$KVer-System.map /boot/
	depmod -eF /boot/sheeva-$KVer-System.map $KVer
}

function NandKernel()
{
	echo "Flashing kernel to NAND"
	# MTDDEVICE should be either /dev/mtd0 or /dev/mtd1
	# depending on which partition contains the kernel uImage

	local Mtd=$(grep uImage /proc/mtd | cut -d' ' -f1 | sed 's#:##')

	flash_eraseall -j /dev/$Mtd
	nandwrite -pm /dev/$Mtd sheeva-$KVer-uImage
}

function RootKernel()
{
	echo "Writing kernel to /boot"
	[[ -d /boot ]] || mkdir /boot
	cp sheeva-$KVer-uImage /boot/
	echo "****************************************************************"
	echo " update your bootcmd to load sheeva-$KVer-uImage"
	echo " or create a link from /boot/sheeva-$KVer-uImage to /boot/uImage"
	echo "****************************************************************"
}

function Usage()
{
	echo "Use --nandkernel to write kernel to NAND"
	echo "Or  --rootkernel to write kernel to /boot"
}

if [[ $# < 1 ]]; then
	Usage
	exit 1
fi

if [[ "$1" == "--nandkernel" ]]; then
	Download
	CheckSize
	ExtractModules
	NandKernel
elif [[ "$1" == "--rootkernel" ]]; then
	Download
	ExtractModules
	RootKernel
else
	Usage
	exit 1
fi