Not able to compile linux kernel

I am using Ubuntu version 15.10 64 bit in virtual box and i have downloaded colibri_VF_LinuxImageV2.6.1Beta1_20161001 and Cross compiler software
gcc-linaro-5.2-2015.11-2-x86_64_arm-linux-gnueabihf.tar.xz.
I am following (http://developer.toradex.com/knowledge-base/build-u-boot-and-linux-kernel-from-source-code) to build U-boot and Linux kernel .

plz get back to me as soon as possible .alt text

What exactly is in the /srv/nfs folder? What is the output of “ls” in that directory? Did you follow the steps and fetch the kernel source as specified here?