install-ubuntu-deps.sh will install all needed dependencies on ubuntu.
build-br.sh will build buildroot for rpi1 by default or the given arch as first parameter.
mk-sdcard-img.sh will take a buildroot build images folder as first parameter
and generate a ready to dd sdcard img to be used on your rpi.
dd-sdcard-img.sh will dd a sdcard tar.xz img on your real sdcard.