Good call. That would work around this current problem nicely. Though, I don’t
know if this problem is with this specific core, or Cyrix chips in general.
I won’t be too worried about the whole exercise. I was going to use it for a
project, but I realized how silly that would be given that you can pull Core 2
Duos with 2GB of RAM out of a dumpster these days.
On Apr 26, 2014, at 2:14 PM, Miod Vallat <m...@online.fr> wrote:
>> The question I have is can I disable the random number generator?s use of
>> that instruction? I?d rather be on -current than years old.
>
> Apart from the following hammer, I see no easy way to achieve this.
>
> Index: i386/machdep.c
> ===================================================================
> RCS file: /cvs/src/sys/arch/i386/i386/machdep.c,v
> retrieving revision 1.536
> diff -u -p -r1.536 machdep.c
> --- i386/machdep.c 29 Mar 2014 18:09:29 -0000 1.536
> +++ i386/machdep.c 26 Apr 2014 19:13:14 -0000
> @@ -1964,7 +1964,8 @@ identifycpu(struct cpu_info *ci)
> }
>
> if (ci->ci_flags & CPUF_PRIMARY) {
> - if (cpu_ecxfeature & CPUIDECX_RDRAND)
> + if (cpu_ecxfeature & CPUIDECX_RDRAND &&
> + vendor != CPUVENDOR_CYRIX)
> has_rdrand = 1;
> #ifndef SMALL_KERNEL
> if (ci->ci_feature_sefflags & SEFF0EBX_SMAP)
