To build and use the buildroot stuff, do the following:

0) Edit the top-level Makefile to define any TARGETs you want to use.  See the examples.  You can also change things like the CPU speed, whether to use softfloat, if you want C++ support, etc here.
1) run 'make'
2) wait while it downloads all the sources and compiles 
3) ... still waiting...
4) You'll now have a u-boot.bin and root_fs_arm or root_fs_arm_nofpu which can be copied to your gumstix.

You do not need to be root to build this system.

Note that this gumstix buildroot is derived from Erik's buildroot which you'll find if you google "buildroot".  It was forked off a branch of Erik's buildroot just before he completely restructured the directory tree, and I haven't had time to fix this yet -- the goal though is to fold back in with the current state of the master buildroot at some point.

-- Craig Hughes <craig@gumstix.com>