[U-Boot] Buildman cookbook

[Wolfgang Denk]

Hello,

it would be nice if we could add a buildman cookbok with hints how to
get started quickly with the most frequent use cases (or add some
quickstart section to the README).

Things that I would like to have better documented include:

- dependencies on external tools:

	-> tools/buildman/buildman --list-tool-chains
	Traceback (most recent call last):
	  File "tools/buildman/buildman", line 10, in <module>
	    import multiprocessing
	ImportError: No module named multiprocessing

  It would be nice if we could list such dependencies.

  Actually we should probably provide such dependencies for U-Boot in
  general - other tools have similar issues, like:

	-> tools/genboardscfg.py 
	Traceback (most recent call last):
	  File "tools/genboardscfg.py", line 19, in <module>
	    import fnmatch
	ImportError: No module named fnmatch

- It would be nice if we could include a sample ".buildman" file,
  and add documentation what the sections ("[toolchain]",
  "[toolchain-alias]") and entries ("root", "rest", "eldk", "arm",
  "aarch64") actually mena, which other options exist, and how the
  tool selects a specific tool chain from this list if multiple
  options are present.

- I work a lot with local branches, and regularly run into this:

  -> tools/buildman/buildman -n -b tq-generic-board
  No section: 'make-flags'
  Branch 'tq-generic-board' not found or has no upstream

  Can we not avoid this?  Or add a default to "master"?

  The README recommends to use "git branch --set-upstream ...", but
  actually I don't want to do that - it is simply not needed.
  Furthermore, git complains;

  -> git branch --set-upstream tq-generic-board master
  The --set-upstream flag is deprecated and will be removed. Consider using --track or --set-upstream-to
  Branch tq-generic-board set up to track local branch master.


Thanks.


Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Man braucht zwei Jahre, um sprechen zu lernen,  und fünfzig Jahre, um
schweigen zu lernen.                               - Ernest Hemingway