Re: NetBSD-9 on 80486?

[Rin Okuyama <rokuyama.rk%gmail.com@localhost>]

Hi,

NetBSD requires 486 instructions *and* x87 FPU; MATH_EMULATE option
was removed back in 2008 before 5.0 was released:

http://cvsweb.netbsd.org/bsdweb.cgi/src/sys/arch/i386/i386/Attic/math_emulate.c?hideattic=0

According to Wikipedia, Cx486DLC lacks internal FPU. This should be
why it does not work. Does the system have slot for external FPU?

Thanks,
rin

On 2021/07/30 9:14, John Klos wrote:
> Hi,
>
> I'm trying to boot NetBSD-9 on an ISA system with a Cyrix 486DLC. The system boots NetBSD 4.0.1 just fine:
>
> https://www.klos.com/~john/dmesg_cyrix_4.0.1
>
> I've compiled a NetBSD-9 LEGACY kernel as well as a custom kernel without ACPI (also tried COPTS="-march=i486"), but all kernels I try to boot (using the 4.0.1 bootloader) hang right after they finish loading:
>
> 5451728+95136+670816 [429136+342778]=0x6aac58
> (hangs)
>
> I know gcc, and therefore NetBSD, stopped supporting 80386 CPUs due to the lack of certain atomic instructions, but I thought 80486 CPUs were still supported.
>
> I also tried NetBSD 5, 6 and 7 kernels, but they do the same thing. It seems that "vga0 at isa?" was removed before NetBSD 8, so I'd expect them to work.
>
> Any ideas?
>
> John Klos