4 - AMD64-specific boot options.
6 - Firmware support for CPU hotplug under Linux/x86-64
8 - Using numa=fake and CPUSets for Resource Management
10 - Context-specific per-processor interrupt stacks.
12 - Configurable sysfs parameters for the x86-64 machine check code.
14 - Memory layout of x86-64 (4 level page tables, 46 bits physical).
16 - Booting Linux via Unified Extensible Firmware Interface.