first pass at building and loading "barebox"

after reading the minimal amount of documentation possible, i just
wanted to see if barebox (the new name for u-boot v2) can load and run
on my beagle, so i git cloned the barebox repo and:

  $ export ARCH=arm
  $ export CROSS_COMPILE=arm-linux- (for ELDK toolchain)
  $ make omap3530_beagle_per_uart_defconfig
  $ make

that generated a barebox.bin, which i copied to my SD/MMC card under
the name "u-boot.bin", then booted off the card to get:

Texas Instruments X-Loader 1.4.2 (Feb 19 2009 - 12:01:24)
Reading boot sector
Loading u-boot.bin from mmc

barebox 2.0.0-rc10 (Dec 20 2009 - 03:02:59)

Board: Texas Instrument's Beagle
Malloc space: 0x87bfff10 -> 0x87ffff10 (size 4 MB)
Stack space : 0x87bf7f10 -> 0x87bfff10 (size 32 kB)
running /env/bin/init...
not found
X-load Beagle>help
Unknown command 'help'
X-load Beagle>

  that *initially* looked promising, but every command i type gives me
"Unknown command". so unless someone wants to explain what i did
wrong, i guess it's time to start reading documentation. i did
*nothing* in terms of setting up the barebox environment, only what
you see above, so it's entirely possible that i still need to
configure the appropriate environment.