beaglebone: better support for starting and creating images

#!/bin/sh

# post-image.sh for BeagleBone

# 2014, Marcin Jabrzyk <marcin.jabrzyk@gmail.com>

# copy the uEnv.txt to the output/images directory

cp board/beaglebone/uEnv.txt $BINARIES_DIR/uEnv.txt

BeagleBone

Intro

=====

To be able to use BeagleBone board with the images generated by

Buildroot, you have prepare the SDCard.

How to build it

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

  $ make beaglebone_defconfig

Then you can edit the build options using

  $ make menuconfig

Compile all and build rootfs image:

  $ make

Result of the build

-------------------

After building, you should get a tree like this:

  output/images/

  ├── am335x-boneblack.dtb

  ├── am335x-bone.dtb

  ├── MLO

  ├── rootfs.ext2

  ├── u-boot.img

  ├── uEnv.txt

  └── zImage

Prepare you SDCard

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

You need to prepare first partition in fat32 and marked as bootable,

and second where you will write rootfs.

Copy the files to boot partition

  $ cp MLO u-boot.img zImage uEnv.txt *.dtb /media/zzzzz

where /media/zzzzz is the mount point

Then you need to write the rootfs image onto SDCard:

  # dd if=rootfs.ext2 of=/dev/xxxxx

where /dev/xxxxx is the second partition. Use:

  # fdisk -l

to check for correct one.

Finish

======

Unmount all mounted SDCard partitions and insert the card to BeagleBone.

Hold the "BOOT" button and apply power. Then release the "BOOT" button.

The output is available on the serial console.

bootpart=0:1

bootdir=

uenvcmd=run loaduimage;run loadramdisk;run findfdt;run loadfdt;run ramboot

BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_DEVTMPFS=y

BR2_TARGET_GENERIC_GETTY_PORT="ttyO0"

# BR2_TARGET_GENERIC_REMOUNT_ROOTFS_RW is not set

BR2_ROOTFS_POST_IMAGE_SCRIPT="board/beaglebone/post-image.sh"

# filesystem

BR2_PACKAGE_AM33X_CM3=y