Re: CPU specific Idle() function in locore_subr.S

[Matt Thomas <matt%3am-software.com@localhost>]

At 05:51 AM 1/20/2005, Tim Kelly wrote:
> On Wed, 19 Jan 2005 13:04:34 -0800
> Matt Thomas <matt%3am-software.com@localhost> wrote:
>
> > My suggestion would be to add a member to cpu.h and call it
> > indirectly.  I can do that code if you want.  It's only a few minutes
> > to do. :)
>
> I see the changes - thanks! I'll start examining how to implement the
> different approaches, starting with adding dssall for Altivec CPUs.
>
> One question I have: in the MPC7450 User's Manual, it states that a
> "context switching" instruction must be given after the mtmsr
> MSR[PSL_EE] instruction. Would you be able to elaborate or clarify this
> statement, as I'm not real clear on what this means.

Read that again, it's "context synchronizing".  See section
2.3.2.4.1.  Basically, there are 3 context synchronizing
instructions: isync, sc, and rfi.  For our purposes, isync
is the one we want.

--
Matt Thomas                     email: matt%3am-software.com@localhost
3am Software Foundry              www: http://3am-software.com/bio/matt/
Cupertino, CA              disclaimer: I avow all knowledge of this message.