#!/bin/bash
# Description: This shell script used to build linux system SDK. You can 
#              use command line argument to specify build target, or select 
#              it by hand if no argument given by command line. More detail
#              information can refer to the help message.
#
#      Author: guowenxue <guowenxue@gmail.com>
#     Version: 1.0.0  


PROJ_PATH=`pwd`

BOARD=sama5d4
PACK_PATH=${PROJ_PATH}/tarballs
PATCH_PATH=${PROJ_PATH}/patches
PATCH_SUFIX=${BOARD}.patch


ROOTFS_SRC=rootfs
ROOTFS_IMG=rootfs-sama5d4.ubi

TFTP_PATH=/tftp
IMGS_PATH=images

target=

set -e

function show_help()
{
	printf "Usage: $1 [system/bootloader/kernel/rootfs/clean]\n\n"

	echo "system    : build all source code "
	echo "bootloader: build bootstrap and u-boot "
	echo "kernel    : build linux kernel "
	echo "rootfs    : build ubifs rootfs images"
	printf "clean     : clean the source code\n\n"
	printf "distclean : remove all the source code\n\n"

	exit 0;
}

function show_banner()
{
	echo "+---------------------------------------------+" 
	printf "$1\n"
	echo "+---------------------------------------------+"
}

function select_target()
{
	targets=("" "system" "bootloader" "kernel" "rootfs" "clean" "distclean")
	echo "Please select a build target:"
	echo "1 <system>    , build all source code "
	echo "2 <bootloader>, build bootstrap and u-boot "
	echo "3 <kernel>    , build linux kernel "
	echo "4 <rootfs>    , build ubifs rootfs image"
	echo "5 <clean>     , clean the source code"
	echo "6 <distclean> , remove all the  source code"
    echo ""

    stty erase '^H'
	read -p "Enter your choise [1-6] : " choice

	if [ $choice -gt 6 ] ; then
		echo "ERROR: Invalid input choice, exit now..."
		exit 1;
	fi

	target=${targets[$choice]}
}



# Usage: start_build [SRCDIR: linux-at91/at91bootstrap/u-boot-at91 ]

function start_build()
{
    SRC_DIR=$1

    if [ ! -d ${SRC_DIR} ] ; then
	    show_banner "|       start decmpress $SRC_DIR packet       |"
        tar -xJf ${PACK_PATH}/${SRC_DIR}.tar.xz 
        cd ${SRC_DIR}

        if [ -f ${PATCH_PATH}/${SRC_DIR}-${PATCH_SUFIX} ] ; then 
            show_banner "|            patch for ${SRC_DIR}             |"
            patch -p1 < ${PATCH_PATH}/${SRC_DIR}-${PATCH_SUFIX}
        fi
    else
        cd ${SRC_DIR}
    fi

	show_banner "|           start $SRC_DIR build task...        |"
    chmod a+x build.sh
    bash build.sh
	show_banner "|            $SRC_DIR build task over!          |"

    cd -
}

function build_ubifs()
{
    ubinize_cfg=ubinize.cfg 
    ubimg_tmp=ubi.img


    # Rootfs partition size
    partition_size=200  # MiB 

    # MT29F4G08: 1 block=64 pages,  1 page = 4096B
    BLOCK_PAGES=64
    PAGE_SIZE=4096

    # Logic Erase Block Size: UBI requires 2 minimum I/O units out of each Physical Erase Block (PEB) for overhead:
    #   1 for maintaining erase count information, and 1 for maintaining the Volume ID information. 

    PEB_SIZE=`expr $PAGE_SIZE \* $BLOCK_PAGES`
    LEB_SIZE=`expr $PEB_SIZE - 2 \* $PAGE_SIZE `

    #UBI reserves 4 blocks space for management and bad PEB handling operations
    # 2 PEBs are used to store the UBI volume table
    # 1 PEB is reserved for wear-leveling purposes;
    # 1 PEB is reserved for the atomic LEB change operation;
    # a% of PEBs is reserved for handling bad EBs. The default for NAND is 1%

    PEB_CNT=`expr $partition_size \* 1024 \* 1024 / ${PEB_SIZE}`
    LEB_CNT=`expr $PEB_CNT - 4 - $PEB_CNT \/ 100 `

    #echo "Parition size ${partition_size}MiB and LEB=$LEB_CNT"
    set -x
    mkfs.ubifs -F -d ${ROOTFS_SRC} -m ${PAGE_SIZE} -e ${LEB_SIZE} -c $LEB_CNT -o ${ubimg_tmp}
    set +x


    # vol_size smaller than the actual size of the partition to leave room for Ubifs internal data. 
    # With "vol_type=dynamic", Ubifs will end up using the whole space automatically
    vol_size=`expr ${partition_size} \- 10`

    printf "[ubifs] \nmode=ubi \nimage=${ubimg_tmp} \nvol_id=0 \nvol_size=${vol_size}MiB\n" > $ubinize_cfg 
    printf "vol_type=dynamic \nvol_name=rootfs \nvol_flags=autoresize\n" >> $ubinize_cfg
    #cat $ubinize_cfg

    set -x 
    ubinize -o ${ROOTFS_IMG} -m ${PAGE_SIZE} -p ${PEB_SIZE} $ubinize_cfg
    set +x

    rm -f $ubimg_tmp $ubinize_cfg
    chmod a+x ${ROOTFS_IMG}
}

function build_rootfs()
{
    if [ ! -d ${ROOTFS_SRC} ] ; then 
        if [ `id -u` != 0 ] ; then 
            printf "\nERROR: decompress rootfs need root privilege, please use sudo!\n\n" 
            exit ; 
        fi 

        tar -xJf ${PACK_PATH}/${ROOTFS_SRC}.tar.xz
    fi

	show_banner "|           start build rootfs image...        |"
    build_ubifs
	show_banner "|           rootfs image build over!          |"

    if [ -d ${IMGS_PATH} ] ; then
        cp -f ${ROOTFS_IMG} ${IMGS_PATH}
    fi

    if [ -d ${TFTP_PATH} ] ; then
        cp -f ${ROOTFS_IMG} ${TFTP_PATH}
    fi

    rm -f ${ROOTFS_IMG}
    ls ${IMGS_PATH}
}


function do_clean()
{
    SRCS="linux-at91 at91bootstrap u-boot-at91"

	show_banner "|         clean project source code           |"
    
    for dir in $SRCS
    do
        if [ -d $dir ] ; then
            cd $dir
            bash build.sh clean
            cd -
        fi
    done
}

function do_distclean()
{ 
    if [ `id -u` != 0 ] ; then 
        printf "\nERROR: distclean need root privilege, please use sudo!\n\n" 
        exit ; 
    fi 

    printf "\nWARNNING: Start remove all the source code and images\n\n"
    rm -rf linux-at91 at91bootstrap u-boot-at91 rootfs ${IMGS_PATH}
}

function do_build()
{
	if   [ "$target" = "system" ] ; then
        start_build at91bootstrap
        start_build u-boot-at91
        start_build linux-at91
        build_rootfs

	elif [ "$target" = "bootloader" ] ; then
        start_build at91bootstrap
        start_build u-boot-at91

	elif [ "$target" = "kernel" ] ; then
        start_build linux-at91

	elif [ "$target" = "rootfs" ] ; then
		build_rootfs

	elif [ "$target" = "clean" ] ; then
		do_clean

	elif [ "$target" = "distclean" ] ; then
        do_distclean

	else
		show_help
	fi
}

mkdir -p ${IMGS_PATH}

# check input arguments for build target
if [ $# -ge 1 ] ; then
	target=$1
else 
	select_target
fi
show_banner "|        choose build target [$target]         |"

do_build