Re: Separating PowerPC 4xx and 6xx arch-specific code

[Simon Burge <simonb%wasabisystems.com@localhost>]

Matt Thomas wrote:

> At 02:46 PM 4/10/2001 +1000, Simon Burge wrote:
> >Folks,
> >
> >We (Wasabi) are working on a port to a 4xx series PowerPC board, and in
> >the interests of sharing as much code as possible between the 4xx family
> >and the 6xx/7xx family I'd like to propose adding some new kernel config
> >options.  What I'm thinking of is:
> 
> IBM 4xx?

The "embedded" processors - the 401, 403, 405 and 440 series.

> >  + Adding to the kernel config file(s):
> >
> >         options         ARCH_4xx        # PowerPC 400 family
> >         options         ARCH_6xx        # PowerPC 600/700 family
> 
> ARCH_IBM? ARCH_MOTO? :)
> 
> >  + Defopt'ing these in files.powerpc as
> >
> >         defopt  opt_arch.h      ARCH_4xx ARCH_6xx
> 
> Exactly what are the differences that need to differentiated?

For a start, the MMU is completely different.  There's also some
register differences - eg, there'd no HID0/HID1 registers on the
4xx chips, so initppc() needs to be changed.  So I'd like to say:

        #ifdef ARCH_6xx
                /* do the HID stuff */
                ...
        #endif

Simon.
--
Simon Burge                            <simonb%wasabisystems.com@localhost>
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