My github account does not exist anymore since 5th of July 2018 because Microsoft has swallowed it.
Since yesterday the 3.10.80-rt88 kernel sources for the Odroid-C1/C1+ are available from my new github account
To compile the sources read http://odroid.com/dokuwiki/doku.php?id=en:c1_building_kernel
Some things change if you use my sources.
Be sure to have the odroidc-3.10.80-rt88 branch selected
and clone with (this is one single line->)
git clone --depth 1 https://github.com/chlorisdroid/linux-rt-odroid-c1.git -b odroidc-3.10.80-rt88
change directory with
.config file with
make arch=ARM odroidc_rt_defconfig