Re: proposal: millicode

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

On 19-Jan-2008 Frank Wille wrote:
> Are there already known fixed offsets, which are used by other operating
> systems, or do we choose them as we like?

Yes, AIX uses 0x3000 for the common code, and I think they implement locks
around 0x4000, but I'm not sure about that one.  Aside from those, the rest we
just choose as we like.

My thought was that we can set aside some pages between 0x3000 and 0x100000
(ie, the start address for most OEA ports) and use those.  I'm thinking 4-8 or
so 4k pages to start.  (This is also why I would like to see the rest of the
OEA ports move to a common start address.  I think currently only sandpoint has
an odd one of 0x90000)

> And please keep in mind that there may be powerpc-ports which cannot
> operate in low-exception-vector mode (MSR bit 25), like amigappc.

It shouldn't matter, as these aren't real exceptions that are called by the
cpu.  However, I am curious as to exactly why the amiga can't operate in that
mode.

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