http://vault.centos.org/6.2/updates/Source/SPackages/
yum install rpm-build redhat-rpm-config unifdef
yum -y install make gcc patchutils xmlto asciidoc elfutils zlib-devel binutils-devel newt-devel python-devel perl hmaccalc elfutils-libelf-devel perl-ExtUtils-Embed
wget http://vault.centos.org/6.2/updates/Source/SPackages/kernel-2.6.32-220.2.1.el6.src.rpm
cd ~/rpmbuild/SPECS/
rpmbuild -bp --target=`uname -m` kernel.spec
cd ~/rpmbuild/BUILD/到下面自己去看。