Ben Harris wrote:

> In article <20001113141304.D19591FF85@thoreau.thistledown.com.au> you write:
>
> >Also, there are lots of places where I've made assumptions about what is
> >a valid ISA for a given architecture.  These should be checked by people
> >familiar with those architectures.  The only ones I'm confident with are
> >mips, alpha, m68k, ns32k and perhaps sparc.  Here's a list of the ISA's:
> >
> >	alpha	ev{4,5,56,6,67}
> >	arm26	arm2
> >	arm32	arm{2,3,4}
> 
> These should be armv2 etc (arm2 usually refers to a specific CPU).  I
> suspect that following GCC would be wise, which gcc.info claims gives:
> 
> 	arm26	armv{2,2a}
> 	arm32	armv{3,3m,4,4t}

Good!  That's the sort of info I'm looking for :)

> >So, anyone disagree with this whole idea or have any suggestions of
> >improvements?
> 
> Question:  If the kernel emulates the instructions provided by later ISAs,
> what should it report?

As I said, my initial goal is to provide for automatic shared library
selection.  Since you want the most efficient library choice for the
current CPU I would say the native ISA.

> >Index: arch/arm26/arm26/machdep.c
> >===================================================================
> >RCS file: /cvsroot/syssrc/sys/arch/arm26/arm26/machdep.c,v
> >retrieving revision 1.5
> >diff -d -p -u -r1.5 machdep.c
> >--- arch/arm26/arm26/machdep.c	2000/09/13 15:00:17	1.5
> >+++ arch/arm26/arm26/machdep.c	2000/11/13 05:01:54
> >@@ -48,6 +48,7 @@ int physmem;
> > char machine[] = MACHINE;
> > char machine_arch[] = MACHINE_ARCH;
> > char cpu_model[] = "Archimedes";
> >+char cpu_isa[] = "arm2";	/* XXX */
> > 
> > /* Our exported CPU info; we can have only one. */
> > struct cpu_info cpu_info_store;
> 
> This would need to be set to "armv2" or "armv2a" in cpu_attach().

That's cool.  This is how things are done with other architectures that
support more than one ISA.  Is there a test we can use to determine
which is which?  Currently there's no mention of armv{2,2a} in the arm26
header files, nor armv{3,3m,4,4t} in the arm32 header files.

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