#! /bin/bash
#
# Dreamplug 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
# Do one of the following three
# setenv arcNumber 2097 # for standard sheevaplugs
# setenv arcNumber 2678 # for e-sata sheevaplugs
# setenv arcNumber 2659 # for guruplugs and dreamplugs
####### 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

ProgName="$0"
KVer=''

ERROR=0
WGET='/usr/bin/wget'
CURL='/usr/bin/curl'
DEPMOD='/sbin/depmod'

for f in $WGET $CURL $DEPMOD; do
	if [[ ! -x $f ]]; then
		echo "missing $f"
		ERROR=1
	fi
done

if (( ERROR )); then
	exit 1
fi

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

function GetDownloadPath()
{
	local site=$1

	local v1=$(echo $KVer | cut -d'.' -f1)
	local v2=$(echo $KVer | cut -d'.' -f2)
	local v3=$(echo $KVer | cut -d'.' -f3)
	local v4=$(echo $KVer | cut -d'.' -f4)
	local path="$v1/$v1.$v2"

	if (( $v1 == 2 )); then
		if [[ -z $v3 ]]; then
			path="$path/$v1.$v2"
		else
			path="$path/$v1.$v2.$v3"
			if [[ -z $v4 ]]; then
				path="$path/$v1.$v2.$v3"
			else
				path="$path/$v1.$v2.$v3.$v4"
			fi
		fi
	else
		if [[ -z $v3 ]]; then
			path="$path/$v1.$v2"
		else
			path="$path/$v1.$v2.$v3"
		fi
	fi

	for (( i = 5; i >= 1; i-- )); do
		testpath=$site/$path/release/$i
		if $CURL -sf $testpath; then
			path=$path/release/$i
			break
		fi
	done

	echo $path
}

function Download()
{
	echo "Downloading files"
	local site1="http://www.xilka.com/kernel"

	local path=$(GetDownloadPath $site1)
	local f='' p=''

	for f in Modules.tar.gz Modules.tar.gz.md5 uImage uImage.md5 System.map; do
		p='sheeva'
		[[ $f != uImage* ]] || p='dream'

		if [[ ! -f $p-$KVer-$f ]]; then
			local s=''
			for s in $site1; do
				if $WGET -c $s/$path/$p-$KVer-$f && [[ -f $p-$KVer-$f ]]; then
					break
				fi
			done
			if [[ ! -f $p-$KVer-$f ]]; then
				echo "Unable to retrieve $p-$KVer-$f"
				exit 1
			fi
		fi
	done
	Md5Compare sheeva-$KVer-Modules.tar.gz sheeva-$KVer-Modules.tar.gz.md5
	Md5Compare dream-$KVer-uImage dream-$KVer-uImage.md5
}

function ExtractModules()
{
	local v1=$(echo $KVer | cut -d'.' -f1)
	local v2=$(echo $KVer | cut -d'.' -f2)
	local v3=$(echo $KVer | cut -d'.' -f3)
	local depmodVer=$KVer
	[[ ! -z $v3 ]] || depmodVer="$v1.$v2.0"
	local extractDir='/'
	[[ ! -L '/lib' ]] || extractDir=$(dirname $(readlink '/lib'))
	[[ -d $extractDir ]] || extractDir="/$extractDir"

	echo "Extracting modules"
	tar x -C $extractDir --overwrite -zf sheeva-$KVer-Modules.tar.gz
	[[ -d /boot ]] || mkdir /boot
	cp sheeva-$KVer-System.map /boot/
	$DEPMOD -eF /boot/sheeva-$KVer-System.map $depmodVer
}

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

function Usage()
{
	echo "Use $ProgName VERSION to write kernel to /boot"
	echo
	echo "    where VERSION is something like 3.4.6"
}

if (( $# < 1 )); then
	Usage
	exit 1
fi

KVer="$1"

Download
ExtractModules
RootKernel