Date: Wed, 21 Sep 2011 11:38:40 +0200 From: Nathan Whitehorn <nwhitehorn@freebsd.org> To: Justin Hibbits <jrh29@alumni.cwru.edu>, FreeBSD PowerPC <freebsd-ppc@FreeBSD.org> Subject: Re: TiBook CPU speed Message-ID: <4E79B0A0.3030906@freebsd.org> In-Reply-To: <CAHSQbTAtswwct0UwtPDSZy687vDrxy8MUFJZUq8i%2BVW5tu=YFA@mail.gmail.com> References: <D0044AC4-3D05-4ACA-89FD-C10AE701EA65@po.cwru.edu> <4E78315F.1040404@freebsd.org> <CAHSQbTAtswwct0UwtPDSZy687vDrxy8MUFJZUq8i%2BVW5tu=YFA@mail.gmail.com>
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On 09/20/11 15:32, Justin Hibbits wrote: > On Tue, Sep 20, 2011 at 2:23 AM, Nathan Whitehorn<nwhitehorn@freebsd.org>wrote: > >> On 09/20/11 05:07, Justin Hibbits wrote: >> >>> Following up on my previous email, the saga of installing FreeBSD on a >>> TiBook, I ran into another problem: The CPU speed is reduced to 666MHz, >>> instead of 1GHz. Is there a way to get it to run at the full 1GHz? >>> >>> >> Just use cpufreq(4) -- the dev.cpu.0.freq sysctl or turn on powerd. >> -Nathan >> > > I looked at that first, but the MPC7455 doesn't have frequency scaling. I > looked at the Linux and Darwin sources after reading a linux page that you > have to explicitly tell it to go full speed, and it turns out it's a PMU > command, and requires a CPU reset, and there are two OFW properties under > /cpu, min-clock-frequency and max-clock-frequency. Ah, yes, this stuff. We only have cpufreq support on PPC 7447/7448 and on later-model G5s. If you're interested in adding support for it, I'm happy to discuss how best to do it. -Nathan
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