Cleaner memory map; avoid < 64K; handle older kernels

Cleaner memory map; avoid < 64K; handle older kernels

Clean up the memory map by making the startup info part of the reloc
segment; this also allows it to be easily prepopulated.

Avoid using < 64K by putting the reloc between the setup and cmdline,
with proper guarding for overflow.

Handle older kernel protocols, and zImage kernels.