To run RTEMS from scratch (without any other bootcode) on the beagles,
you can comfortably load the executables over JTAG using gdb. This is
necessarily target-specific however.

1. BBXM

  - For access to JTAG using openocd, see simscripts/bbxm.cfg.
  - openocd then offers access to gdb using simscripts/gdbinit.bbxm.
  - start openocd using bbxm.cfg
  - copy your .exe to a new dir and that gdbinit file as .gdbinit in the same dir
  - go there and start gdb:
    $ arm-rtems4.11-gdb hello.exe
  - gdb will invoke the BBXM hardware initialization in the bbxm.cfg
    and load the ELF over JTAG. type 'c' (for continue) to run it.
  - breakpoints, C statement and single-instruction stepping work.

2. beaglebone white

This has been tested with openocd and works but not in as much detail as for
the BBXM yet (i.e. loading an executable from scratch).