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 for <freebsd-hackers@freebsd.org>; Mon, 20 Jun 2016 10:57:53 +1000 (EST)
Subject: [solved]: Re: enabling cpu "features" in custom kernel
To: freebsd-hackers@freebsd.org
References: <2fa5c2cb-81eb-d44a-3011-db27035e7965@herveybayaustralia.com.au>
 <092CD08F-3896-451D-8A7E-8DCB056D0118@FreeBSD.org>
From: Da Rock <freebsd-hackers@herveybayaustralia.com.au>
Message-ID: <8e9bb248-7c08-436e-6550-c054f449a483@herveybayaustralia.com.au>
Date: Mon, 20 Jun 2016 10:57:53 +1000
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On 17/06/2016 20:20, Dimitry Andric wrote:
> On 16 Jun 2016, at 14:35, Da Rock <freebsd-hackers@herveybayaustralia.com.au> wrote:
>> I'm just trying to get my head around kernel building and clang.
>>
>> If I want to enable certain features available on my cpu which are available by clang, how do I enable them? As I understand it using ccflags is a no no (ie /etc/make.conf), so how do I go about enabling them? I seem to be missing something in my research here...
> You can set CPUTYPE in /etc/make.conf, for example:
>
> CPUTYPE?=broadwell
>
> then it will be automatically picked up in the correct places during
> buildworld, or during ports building.
>
> See also make.conf(5) and /usr/share/examples/etc/make.conf.
>
> -Dimitry
>
Thank you for that lead. It wasn't quite on it, but referring to 
/usr/share/mk/bsd.cpu.mk provided the answers I sought.