[PATCH] Utilize i686, SSE and MMX by default on FreeBSD/i386

[Daniel Eischen]

On Fri, 19 Mar 2010, Scott Long wrote:

>
> On Mar 19, 2010, at 12:36 PM, Julian Elischer wrote:
>
>> John Baldwin wrote:
>>> On Thursday 18 March 2010 9:06:31 pm Xin LI wrote:
>>>> Hi,
>>>>
>>>> I think it doesn't really make sense to by default use MACHINE_CPU=i486
>>>> when the kernel is built with SSE by default today.
>>>>
>>>> Attached patch uses i686 SSE MMX by default, the user can always change
>>>> the default setting by overriding CPUTYPE (they have to do it as SSE is
>>>> enabled by default for several years).
>>> The kernel is only built with support for userland applications using SSE, it does not _use_ SSE.  Similarly, the kernel is built with support for PG_NX provided on 64-bit processors, but it does not do so by failing to support older 32-bit processors.  I think this change is premature.  Users can already set CPUTYPE in make.conf.  Also, most modern x86 server-class machines are
>>> 64-bit in which case they would be running FreeBSD/amd64 and using SSE
>>> already.
>>
>>
>> and a lot of low power boxes (e.g. soekris) are 586 class.
>>
>
> Are these machines typically installed via a GENERIC kernel from 
> freebsd.org release CD's?  Maybe there's a market to create a new 
> mini-distribution tailored for these devices.  It would come with a 
> suitable kernel and install/setup tools.

Well, we have nanobsd, but having a suitable install tool
for small flash-based systems where you want a nanobsd-like
setup (readonly filesystems) would be very nice.  I try
to write procedures for our embedded systems so others
(neophytes) can create and burn them, but it might be
easier for someone to get started with embedded systems
if they could do it from a release using an install tool.

-- 
DE