a minimal, from scratch, build for the BBB, and further developments

i know i've posted this before but if people want to build a
bootable minimal image for the BBB from the ground up, this:


is a recipe i used in a course last week, where students formatted a
fresh SD card, then downloaded, configured, installed and booted to a
root prompt.

  important notes:

* the *current* u-boot now incorporates tom tini's patch that switches
from using uImage back to zImage, which is what i plan on using from
now on

* there is absolutely no need for a uEnv.txt file if all you want to
do is boot to the command line, which is all i wanted the students to

* i am intensely lazy and i steal robert nelson's minimal root
filesystem, to which you *must* make the two small changes listed
under "The Root Filesystem" section

  if anyone wants to test out that recipe and point out any glitches
or places where i'm unclear, i'm always open to feedback.

  also, you can see that the rest of that page lists enhancements the
student can start adding to their rootfs, and i'm definitely open to
nice writeups of things like that -- there are clearly *many* things i
can add as future labs for a beginner embedded linux class.