Fixes two problems with the GDT when compiling for uniprocessor:
- There's no percpu segment, so trying to load its selector into %fs fails.
Use a null selector instead.
- The real gdt needs to be loaded at some point. Do it in cpu_init().
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>