> > We had a problem in user-space apps all showing 0 for floating-point
> > results because we hadn't set the ST0_FR bit to 0, and we had a
mis-match
> > between user libraries (MIPS3k-compatible) and the floating point
registers.
> > We noticed the problem when we couldn't run "ps" or "rm" correctly and
tracked
> > it down from some old postings by Ralf and friends. Maybe this is your
> > problem, too?
> >
> > I added this to our setup call:
> >
> > set_cp0_status(ST0_FR, 0);
>
> Problem solved before I finished my first cup of coffee. Thanks!
>
> I bet this problem will show up here and there depending on how the boot
> code sets cp0. Seems like adding the above line in a mips generic init
> routine would be a good thing.
I had essentially the same problem at MIPS a year or two ago,
and I could have *sworn* that my fix, which ORed ST0_FR into
the initial Status register value set in the startup assembly code,
had made it into the standard distributions. It's at about line 530
of head.S, where a term is added to make the instruction
li t1,~(ST0_CU1|ST0_CU2|ST0_CU3|ST0_KX|ST0_SX|ST0_FR)
I spent days thinking it was a mipsel library problem,
because it only turned up when I tried exercising a
little-endian version of the same kernel that worked
sell big-endian on the Indy. But of course it was all
due to the mipsel system having a boot-prom that
cleverly enabled all the FP registers for me...
Kevin K.
