git clone git://git.denx.de/u-boot.git
cd u-boot

eval $( grep -E "export NUMJOBS|export DISTCC_HOSTS|PATH=/tmp/DISTCC" ~/armedslack/dbuild |grep -v "^#" ) > /dev/null 2>&1
export NUMJOBS=-j$[$(sed 's?[^0-9]*/?+?g' <<<$DISTCC_HOSTS)]
export PATH=/tmp/DISTCC:$PATH

make $NUMJOBS guruplug

=========

http://wiki.beyondlogic.org/index.php?title=GuruPlug_Upgrading_uBoot

wget ftp://ftp.denx.de/pub/u-boot/u-boot-latest.tar.bz2
tar -xjf u-boot-latest.tar.bz2
cd u-boot-2014.01

tar xf ../*debian*z
grep -Ev '^$' debian/patches/series | while read pf; do patch -p1 < debian/patches/$pf ; done

By default, the GuruPlug & SheevaPlug configuration does not enable Device Tree Support and needs to be manually enabled. 
To do this add the following to /include/configs/guruplug.h

/* Enable flat device tree support */
#define CONFIG_OF_LIBFDT


make distclean
make sheevaplug_config
make u-boot.kwb