[CentOS] Kernel build on i386 and nohighmem forbidden?

I looked in the release notes, but maybe I missed it. Is it not possible to 
build a kernel from CentOS 4.3 (using 2.6.9-34.0.1) with HIGHMEM support turned 
off? This is for a machine with 512mb.

When I try to build the kernel, I get _etext undefined symbol on line 100 of 
pageattr.c in arch/i386/mm.

Linus