freescale/imx6-sabresd: document how to create a bootable SD

#!/bin/sh

set -u

set -e

PROGNAME=$(basename $0)

usage()

{

    echo "Create an SD card that boots on an i.MX6DL SABRESD board."

    echo "It is supposed to work also for the i.MX6Q SABRESD board, but"

    echo "it this is not tested."

    echo

    echo "Note: all data on the the card will be completely deleted!"

    echo "Use with care!"

    echo "Superuser permissions may be required to write to the device."

    echo

    echo "Usage: ${PROGNAME} <sd_block_device>"

    echo "Arguments:"

    echo "  <sd_block_device>     The device to be written to"

    echo

    echo "Example: ${PROGNAME} /dev/mmcblk0"

    echo

}

if [ $# -ne 1 ]; then

    usage

    exit 1

fi

if [ $(id -u) -ne 0 ]; then

    echo "${PROGNAME} must be run as root"

    exit 1

fi

DEV=${1}

# The partition name prefix depends on the device name:

# - /dev/sde -> /dev/sde1

# - /dev/mmcblk0 -> /dev/mmcblk0p1

if echo ${DEV}|grep -q mmcblk ; then

    PART="p"

else

    PART=""

fi

PART1=${DEV}${PART}1

PART2=${DEV}${PART}2

# Unmount the partitions if mounted

umount ${PART1} || true

umount ${PART2} || true

# First, clear the card

dd if=/dev/zero of=${DEV} bs=1M count=20

sync

# Partition the card.

# SD layout for i.MX6 boot:

# - Bootloader at offset 1024

# - FAT partition starting at 1MB offset, containing uImage and *.dtb

# - ext2/3 partition formatted as ext2 or ext3, containing the root filesystem.

sfdisk ${DEV} <<EOF

32,480,b

512,,L

EOF

sync

# Copy the bootloader at offset 1024

dd if=output/images/u-boot.imx of=${DEV} obs=512 seek=2

# Prepare a temp dir for mounting partitions

TMPDIR=$(mktemp -d)

# FAT partition: kernel and DTBs

mkfs.vfat ${PART1}

mount ${PART1} ${TMPDIR}

cp output/images/uImage ${TMPDIR}/

cp output/images/*.dtb  ${TMPDIR}/

sync

umount ${TMPDIR}

# ext2 partition: root filesystem

mkfs.ext2 ${PART2}

mount ${PART2} ${TMPDIR}

tar -C ${TMPDIR}/ -xf output/images/rootfs.tar

sync

umount ${TMPDIR}

# Cleanup

rmdir ${TMPDIR}

sync

echo Done

*******************************************************

Freescale i.MX6Q and i.MX6DL SABRESD development boards

*******************************************************

This file documents the Buildroot support for the Freescale SABRE Board for

Smart Devices Based on the i.MX 6 Series (SABRESD).

Read the SABRESD Quick Start Guide for an introduction to the board:

http://cache.freescale.com/files/32bit/doc/quick_start_guide/SABRESDB_IMX6_QSG.pdf

Build

=====

First, configure Buildroot for your SABRESD board.

For i.MX6Q:

  make freescale_imx6qsabresd_defconfig

For i.MX6DL:

  make freescale_imx6dlsabresd_defconfig

Build all components:

  make

You will find in ./output/images/ the following files:

  - imx6dl-sabresd.dtb or imx6q-sabresd.dtb

  - rootfs.ext2

  - rootfs.tar

  - u-boot.imx

  - uImage

Create a bootable SD card

=========================

To determine the device associated to the SD card have a look in the

/proc/partitions file:

  cat /proc/partitions

Run the following script as root on your SD card. This will partition the card

and copy the bootloader, kernel, DTBs and root filesystem as needed.

*** WARNING! The script will destroy all the card content. Use with care! ***

  ./board/freescale/imx6sabresd/create-boot-sd.sh <your-sd-device>

Boot the SABRESD board

======================

To boot your newly created system (refer to the SABRESD Quick Start Guide for

guidance):

- insert the SD card in the SD3 slot of the board;

- locate the BOOT dip switches (SW6), set dips 2 and 7 to ON, all others to OFF;

- connect a Micro USB cable to Debug Port and connect using a terminal emulator

  at 115200 bps, 8n1;

- power on the board.

Enjoy!

References

==========

https://community.freescale.com/docs/DOC-95015

https://community.freescale.com/docs/DOC-95017

https://community.freescale.com/docs/DOC-99218