[coreboot] xgcc folder is not made!

[ali hagigat]

I downloaded the coreboot version 4 for a Ubuntu system. When i want to execute
util/crossgcc/make

It stops complaining that there is an error building GDB!
If i want to make without GDB like by buildgcc, it stops , the error
is that it can not find one h file in xgcc and iasl can not be made!

xgcc folder is not filled! What is the problem?

Regards

(PS. Besides when i want to compile the source code of coreboot by its
makefile, it stops and complains that one symbol has two contradict
types. Should i run `buildgcc`  before making the Coreboot source
code? )