building arm images. This is similar to tools/vmimage.subr
used for building virtual machine disk images. By default,
only arm_create_disk() and arm_install_base() contain real
functionality here, and arm_install_uboot() must be overridden
in the arm/KERNEL.conf file.
In release.sh, make create_arm_armv6_build_release() do
something now.
In arm/BEAGLEBONE.conf, set IMAGE_SIZE, PART_SCHEME, FAT_SIZE,
FAT_TYPE, and MD_ARGS, as well as make arm_install_uboot()
functional.
Parts of this were taken from disecting a previous BEAGLEBONE
image, and other parts obtained from Crochet sources.
Sponsored by: The FreeBSD Foundation
db697baa50