Isso funcionou para mim !! Obrigado !!!
sudo apt-get install swig gcc m4 python python-dev libgoogle-perftools-dev mercurial scons g++ build-essential
hg clone http://repo.gem5.org/gem5
cd gem5/
scons build/ARM/gem5.opt -j2
build/ARM/gem5.opt configs/example/se.py -c tests/test-progs/hello/bin/arm/linux/hello