U-Boot loader for Gumstix Duovero.

To install this bootloader, copy the files MLO and u-boot.img to the FAT
partition on an SD card. Normally this is partition 1, but different
partitions can be set with U-Boot environment variables.

This version is patched so that:
 * ELF and API features are enabled.
 * The default environment is trimmed to just what's needed to boot.
 * The saveenv command writes to the file uboot.env on the FAT partition.
 * The DTB file name is passed to ubldr using the fdtfile env variable.
   The default is omap4-duovero-parlor.dtb for a Parlor expansion board.
   ubldr loads the DTB from /boot/dtb/ on the FreeBSD partition.
   (Not tested)
 * By default, it loads ELF ubldr from file ubldr on the FAT partition
   to address 0x88000000, and launches it.

For information about running FreeBSD on Duovero, see
 https://wiki.freebsd.org/FreeBSD/arm/Duovero

For general information about U-Boot see WWW: http://www.denx.de/wiki/U-Boot
