Messages in this thread | | | Date | Thu, 30 Oct 1997 04:24:58 +0100 (MET) | From | Gabriel Paubert <> | Subject | Re: Kernels 2.1 with 386DX/387 IRQ13 PC boxes |
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On Wed, 29 Oct 1997, Richard B. Johnson wrote:
> On Wed, 29 Oct 1997, C. Scott Ananian wrote: > > > On Tue, 28 Oct 1997 root <root@mangue.ibm.net> wrote: > > > > > Now my question : How to test it? How to generate an IRQ13 interrupt? > > main() { double zero=0.0 ; double one=1.0; one /= zero; } > >
You first have to unmask FP exceptions. By default they are all masked, and you will never get any interrupt, as you can check with the following simple code:
main() { unsigned short cw; asm("fstcw %0": "=m" (cw):); printf("Initial FPU CW:%x\n", cw); }
gives: Initial FPU CW: 37f
Gabriel.
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