Subject: Re: VFP support?
To: Chris Gilbert <chris@dokein.co.uk>
From: Matt Thomas <matt@3am-software.com>
List: port-arm
Date: 09/12/2007 19:37:15
On Sep 12, 2007, at 4:19 PM, Chris Gilbert wrote:

> Matt Thomas wrote:
>>
>> I have a few ARMs with real VFP.  What is the state of VFP support in
>> NetBSD?
>> Does it work?  Should it work?
>
> I don't think it's supported at the moment, I don't remember anyone
> adding code to save the VFP regs on a context switch which is probably
> the main bit of kernel work needed.
>
> gcc appears to have vfp support as a vfp file does exist:
> src/gnu/dist/gcc4/gcc/config/arm/vfp.md
> possibly enabled by using:
> -mfpu=vfp
>
> Also I note that sys/arch/arm/include/float.h has some #ifndef  
> __VFP_FP__
>
> Is it a full vfp implementation, or is it like the original floating
> point where the some instructions are in hardware, and some are  
> emulated?
>
> So I guess it's been thought about, but as your possibly the first
> person with a VFP capable chip you get the fun of making it work :)

It's a full implementation as far as I can tell.