> > there shouldn't be a special directory for it.  It's simple a 603 (OEA).
> 
> Sure, agreed about the core. I was speaking about the various
> peripherals that the SoC can drive.

I'd propose somewhat redundant but straightforward hierarchy for SoCs;
create a subdirectory (called cpu/ here, but whatever you want) and
under it have one directory for each supposedly compatible SoC
versions and put definitions (mainly for peripherals), like:

	src/sys/arch/powerpc/cpu/mpc52xx
	src/sys/arch/powerpc/cpu/mpc74xx
	src/sys/arch/powerpc/cpu/mpc83xx
	src/sys/arch/powerpc/cpu/mpc85xx
	src/sys/arch/powerpc/cpu/mpc86xx
	:

The reason I did this (locally) and I like this is that I want to keep
(register) definitions exactly corresponding to their datasheets.

If you go "these modules look similar, let's share headers and codes"
way, it's you who has to figure out the differences and
(in)compatibilities of versions.  I once tried this for SuperH CPUs,
and I concluded this is just plain waste of time.  Sharing code didn't
save my time at all.

Newer core definitions and its code (e300, e500, e600, ...) can be
aligned to current oea/ directory.

Masao

P.S. I feel populating src/sys/arch/* directory is ugly.