#! /bin/sh
#############################################################################
# Copyright (C) 2007-2009 Laboratório de Sistemas e Tecnologia Subaquática  #
# Departamento de Engenharia Electrotécnica e de Computadores               #
# Rua Dr. Roberto Frias, 4200-465 Porto, Portugal                           #
#############################################################################
# Author: Ricardo Martins                                                   #
#############################################################################

base='/opt/lsts/glued'
hostname="$(hostname)"
flashcp='/usr/sbin/flashcp'
scratch="$base/.glued"

clean()
{
    if [ -d "$base"/.glued-new ]; then
        rm -rf "$base"/.glued-new
    fi

    if [ -d "$base"/.glued-old ]; then
        rm -rf "$base"/.glued-old
    fi
}

version()
{
    file="$(ls -1 $base/glued-*-*-rootfs.tar.bz2 2> /dev/null | head -n 1)"

    if [ -z "$file" ]; then
        return 1
    fi

    # Filter version.
    ver="$(echo $file | sed "s%$base/glued-%%")"
    ver="$(echo $ver | sed "s%-$hostname-bundle\.tar%%")"

    export fw_version="$ver"
    export fw_file="$file"

    return 0
}

new_unpack()
{
    echo -n "* Unpacking new rootfs... "
    mkdir ${base}/.glued-new
    tar -C ${base}/.glued-new -x -f "$fw_file"; rv=$?
    if [ -d /etc/dropbear ]; then
        cp -a /etc/dropbear ${base}/.glued-new/etc
    fi

    if [ $rv -eq 0 ]; then
        rm "$fw_file"
        echo "done"
        return 0
    fi

    echo "failed"
    return 1
}

kernel_dst()
{
    echo -n "* Detecting kernel destination... "

    # Kernel resides in the root filesystem.
    if [ -d /boot/extlinux ]; then
        echo "filesystem"
        return 0
    fi

    if ! [ -f /proc/mtd ]; then
        echo "filesystem"
        return 0
    fi

    grep 'uboot=ext2' /proc/cmdline > /dev/null 2>&1
    if [ $? -eq 0 ]; then
        echo "filesystem"
        return 0
    fi

    export fw_kernel_mtd="$(grep \"kernel\" /proc/mtd | cut -f1 -d':')"
    if [ -z "$fw_kernel_mtd" ]; then
        export fw_kernel_mtd="$(grep \"Kernel\" /proc/mtd | cut -f1 -d':')"
        if [ -z "$fw_kernel_mtd" ]; then
            echo "failed to detect kernel's MTD partition"
            return 1
        fi
    fi

    echo "mtd"
    return 0
}

kernel_upgrade()
{
    # Upgrade MTD
    if [ -n "$fw_kernel_mtd" ]; then
        echo -n "* Upgrading kernel... "
        "$flashcp" -v "$base/.glued-new/boot/kernel" /dev/"$fw_kernel_mtd" > /dev/null 2>&1
        if [ $? -ne 0 ]; then
            echo "failed"
            return 1
        fi
        echo "done"
        return 0
    fi
}

uboot_part_upgrade()
{
    label="$1"
    dev="$2"

    echo -en "* $label: probing bootloader partition... "
    if ! [ -b "$dev" ]; then
        echo 'not present'
        return 0
    fi
    echo 'present'

    echo -en "* $label: mounting bootloader partition... "
    mount -t vfat "$dev" /mnt > /dev/null 2>&1
    if [ $? -ne 0 ]; then
        echo "failed"
        return 0
    fi
    echo 'done'

    for f in MLO u-boot.img; do
        if [ -f /mnt/MLO ]; then
            echo -en "* $label: Replacing $f... "
            cp "$base/.glued-new/boot/$f" /mnt
            echo 'done'
        fi
    done

    echo -en "* $label: unmounting bootloader partition... "
    umount /mnt > /dev/null 2>&1
    if [ $? -ne 0 ]; then
        echo 'failed'
        return  1
    fi

    sync && sync && sync && sync
    echo 'done'
    return 0
}

uboot_part_upgrade_check()
{
    # Check if board is a BeagleBone black.
    dmesg | grep -i 'machine model' | grep -i beaglebone
    if [ $? -eq 0 ]; then
        uboot_part_upgrade 'BeagleBone Black' '/dev/mmcblk1p1'
        return 0
    fi

    # Check if board is a IGEPv2.
    dmesg | grep -i 'machine model' | grep -i igepv2
    if [ $? -ne 0 ]; then
        uboot_part_upgrade 'IGEPv2' '/dev/mmcblk0p1'
        return 0
    fi

    return 0
}

old_move()
{
    echo "* Mounting rootfs read-write..."
    mount -o remount,rw /

    echo "* Unmounting pseudo filesystems..."
    umount /sys
    umount /dev/pts
    umount /dev/shm
    umount /proc

    if [ -f /boot/extlinux/extlinux.sys ]; then
        /bin/chattr -i /boot/extlinux/extlinux.sys
    fi

    echo "* Moving old rootfs..."
    mkdir $base/.glued-old &&
    mv /bin /boot /etc /init /lib /proc /root /sbin /sys /tmp /usr /var $base/.glued-old &&
    $base/.glued-old/bin/echo "* Moving new rootfs into place..." &&
    $base/.glued-old/bin/busybox cp -a $base/.glued-new/* / &&
    $base/.glued-old/bin/echo "* Mounting procfs..." &&
    $base/.glued-old/bin/busybox mount -t proc proc /proc &&
    if [ -d "/boot/extlinux" ]; then
        $base/.glued-old/usr/sbin/extlinux -i /boot/extlinux
    fi

    $base/.glued-old/bin/echo "* Flushing filesystem cache... "
    $base/.glued-old/bin/busybox sync
    $base/.glued-old/bin/busybox sync
    $base/.glued-old/bin/busybox sync
    $base/.glued-old/bin/busybox sync
    $base/.glued-old/bin/busybox sync

    $base/.glued-old/bin/echo "* Preparing reboot... "
    $base/.glued-old/bin/busybox mount -o remount,ro /opt
    $base/.glued-old/bin/busybox umount /proc
    $base/.glued-old/bin/busybox touch /.reboot
    $base/.glued-old/bin/busybox kill -SIGQUIT 1
    exit 0
}

start()
{
    clean
    version || return 1
    kernel_dst || return 1
    new_unpack || return 1
    uboot_part_upgrade_check || return 1
    kernel_upgrade || return 1
    old_move || return 1
}

stop()
{
    echo -n ""
}