Re: Tim Rightnour

[Tim Rightnour <root%garbled.net@localhost>]

On 09-Apr-2008 Toru Nishimura wrote:
> Kudo.  I'm impressed by the mods encapsulated inside common powerpc/.
> This implies NetBSD can enjoy powerpc SMP at free of charge, doesn't it?

To some degree, yes.  Basically, one needs to write an IPI driver for the
machine, and the md_* functions that appear in port/cpu.c.  The most difficult
of these to write, is the trampoline code, which tells the secondary CPU to
spin up.  Ofppc uses different trampoline code than macppc did, and in theory,
another port could use either, depending on how soon in the boot process the
cpu needs to be spun up.  (ofppc had to be spun up super-early)  There are two
parts to the trampoline, the routine that initiates it, and then the routine
that the cpu executes.

We did most of this work during the ppcoea-rennovation, copying out what macppc
had, and trying to abstract it.  ofppc is the first port (other than macppc) to
successfully use it.

In theory, bebox could be next, or possibly prep.  Prep is likely very
difficult to write the trampoline for.  As for bebox, I'm not sure at all, as
it needs both IPI and trampoline code.

---
Tim Rightnour <root%garbled.net@localhost>
NetBSD: Free multi-architecture OS http://www.netbsd.org/
Genecys: Open Source 3D MMORPG: http://www.genecys.org/