I am having trouble configuring my kernel for X86_64 architecture using Menuconfig. There appears to be several symbols that need to be changed including CONFIG_X86_64=y and 64BIT=y. When I import an old config file that was setup for 64 Bit architecture from 2.6.9 into my newer kernel menuconfig, It changes everything back to 32 bit. Does anyone have instructions for configuring a 64bit kernel?