RE: ipengine boot

more things:
os/boot/mpc/l.s and os/boot/mpc/init*.c
contain 1st-level boot code that runs from flash but has data in RAM.
init*.c initialise the memory controllers on different mpc8xx
platforms.  they are odd because sysinit is called when running
with both code and initialised data in flash (because DRAM isn't ready yet),
so the code plays games with SB to address the initialised data in flash
until DRAM is ready, then switches it back.

it also includes unsqueeze code i mentioned earlier.
os/boot/puma has an ARM version of it.

both are based too much on the pc boot program because
the person intended to use them needed something familiar.