On Thu, 23 Aug 2001, Gleb O. Raiko wrote:
> In order to read a PCI ID, you need to know how to do it. In pc world,
> you may rely on configuation access types, at least, ports are known. On
> other arches, you need to know where such "ports" are. Even if hardware
> supports, say, configuration type 1 accesses, developers are free to put
> port addresses anywhere.
Yep, I see. MIPS is quite special here, because, unlike for Alphas,
PowerPCs, SPARCs, etc. there is a couple of independend vendors making
systems, so there is no single way of obtaining a system ID. So you need
to know how to access chipset from elsewhere.
> > How do you set up mips_machtype on your system in the first place? At
> > kernel_entry the code does not know what machine it's running on anyway,
> > so it has to set mips_machtype based on a detection algorithm.
>
> First, mips_machtype is accessed far later than kernel_entry is
That's quite obvious -- nothing can be done in Linux earlier. ;-) But
you need to initialize mips_machtype somehow.
> executed. Personally, I am lucky :-), I may read firmware environment
> variables.
Well, other system might as well (e.g. DECstations can), but that doesn't
solve the problem -- to access firmware variables you need to know which
kind of firmware you are on.
--
+ Maciej W. Rozycki, Technical University of Gdansk, Poland +
+--------------------------------------------------------------+
+ e-mail: macro@ds2.pg.gda.pl, PGP key available +
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