BeagleBone

SD Card Creation

1. At a minimum, you need to create the first partition on an SD card to store the bootloader files and kernel uImage. For the root filesystem you can choose to use either a second partition on the SD card or a USB drive.
2. The first partition should be FAT16 LBA (partition type 0E), and a size of 128MB is plenty of space for the needed files. Also flag this partition as bootable.
   Format the partition with mkfs.vfat, for example: mkfs.vfat -F 16 -n "bootloader" /dev/mmcblk0p1
3. If you plan to use the SD card for the root filesystem as well, create a second partition of type Linux filling the rest of the free space, preferably at least 1-2GB.
   Format the partition with mkfs.ext3, for example: mkfs.ext3 -L "rootfs" /dev/mmcblk0p2
4. If you plan to use a USB drive for the root filesystem, create a first partition on the drive of type Linux using at least 1-2GB.
   Format the partition with mkfs.ext3, for example: mkfs.ext3 -L "rootfs" /dev/sdb1
5. Download the BeagleBone bootloader tarball and extract the files onto the first partition of the SD card. These files contain the bootloaders needed to load the kernel. The file MLO needs to be the first file put onto the FAT partition, and extracting the tarball as-is should do this for you. If you have problems getting to U-Boot, re-format and place the files manually.
6. Download the root filesystem tarball and extract it (as root) to the ext3 partition on either the SD card or the USB drive. It is important to do this as root, as special files need to be created as part of the filesystem that can only be created by root.
7. Copy /boot/uImage from the ext3 partition to the fat16 partition.

Bootloader configuration

1. The bootloader tarball you downloaded while making your MicroSD card contains a default U-boot configuration in the uEnv.txt file. If you need to change the configuration for any reason, just edit that file. It is not necessary to use mkimage or boot.scr scripts at all, delete them from the card if you have already put them in place.
2. The default uEnv.txt configuration file loads the kernel from the fat16 partition (which is also mounted over /boot when the system is running to make upgrades easier), and tells the kernel to look for the root filesystem on the 2nd MicroSD partition. If you put root on a USB drive, change the root= line in uEnv.txt to say "root=/dev/sda1".