603 support

[mol-general@lists.maconlinux.org]

On Tue, Apr 30, 2002 at 03:42:15PM -0500, Greg Alexander wrote:
> I'm interested in getting 603 support working.  From posts on the list
> it looks like it isn't.
> 
> I've been looking at the code in 603.S, and one glaring thing stands out
> at me so far:
> 
> Why do we believe that r0 gets the ctr after a page table searching
> interrupt?  

The vectors in 603.S are not invoked directly; they are
called from trampolines. The trampolines check whether MOL owns 
the processor or not. If MOL is the owner, then the vector
in 603.S is invoked. The glue for the 603 exceptions saves 
ctr in r0 (ctr is used for the branch). The actual code
is in src/kmod/include/molasm.h.

> Other than the page table searching interrupts (which we make
> disappear), what other 603-specific issues are there?  I'd like to check
> some of these also.

Well, there is the code to allocate the page table and set
SDR1 (in mmu.c), but that should be all. 

Note that MOL *did* run on 603 processors when the kernel
used page tables for the 603.


Cheers,

/Samuel