http://e2e.ti.com/support/dsp/omap_applications_processors/f/42/p/29363/102101.aspx   http://lxr215.javaeye.com/blog/771241   mkdir u-boot
cd u-boot
git-init-db
git-pull -a -k http://www.denx.de/git/u-boot.git
git-pull的好处是能够断点续传。