OSDev.org

bubach wrote:

sysenter/exit works on intel & amd 32-bits, and intel 64-bits
syscall/ret works on amd 32-bit and intel/amd 64-bit

it does?nt seem that hard.. u just use sysenter/exit if your os is 32 bit and syscall/ret on 64 bit..

Yes and no. Sysenter/exit works on all 32-bit systems, so yes for 32bit systems it's easy. But, intels 64-bit chips do not support syscall/ret in compatibility mode (32bit in long mode) so you still have a problem.