First the question: is there a good reason that set_dec() is a no-op
on 4xx, rather than setting the PIT? It's not a perfect approximation
to the decrementer, but as far as I can tell it should be close enough
for the next_dec code from arch/ppc/kernel/time.c to work properly.
Second a patch - the below adds floating point emulation to the 4xx.
With this patch I've been able to boot a Walnut to a shell. Of
course, anything I try to run from the shell dies horribly...
diff -urN ../linuxppc_2_4_devel/arch/ppc/kernel/traps.c
linux-bungo/arch/ppc/kernel/traps.c
--- ../linuxppc_2_4_devel/arch/ppc/kernel/traps.c Wed Aug 29 10:41:56 2001
+++ linux-bungo/arch/ppc/kernel/traps.c Thu Aug 30 17:02:36 2001
@@ -1,5 +1,5 @@
/*
- * BK Id: SCCS/s.traps.c 1.23 08/29/01 08:57:35 paulus
+ * BK Id: %F% %I% %G% %U% %#%
*/
/*
* linux/arch/ppc/kernel/traps.c
@@ -265,7 +265,12 @@
#endif
_exception(SIGTRAP, regs);
} else {
+#ifdef CONFIG_MATH_EMULATION
+ if (do_mathemu(regs))
+ _exception(SIGILL, regs);
+#else
_exception(SIGILL, regs);
+#endif
}
#else
if (regs->msr & 0x100000) {
--
David Gibson | For every complex problem there is a
david at gibson.dropbear.id.au | solution which is simple, neat and
| wrong. -- H.L. Mencken
http://www.ozlabs.org/people/dgibson
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