May 26, 2018


U-Boot loader for BeagleBone and BeagleBone Black.

To install this bootloader, copy the files MLO and bb-uboot.img to the FAT partition on an SD card or the eMMC. 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 chosen based on the board model and passed to ubldr using the fdtfile env variable. ubldr loads the DTB from /boot/dtb/ on the FreeBSD partition.
  • By default, it loads ELF ubldr from file bbubldr on the FAT partition to address 0x88000000, and launches it.

Note prefixing the boot files with ‘bb’ allows building images with boot bits for more than one board.

For information about running FreeBSD on BeagleBone or BeagleBone Black, see https//

For general information about U-Boot see WWW http//