Date: Fri, 09 Jul 1999 10:10:37 +0200 From: Poul-Henning Kamp <phk@critter.freebsd.dk> To: Ville-Pertti Keinonen <will@iki.fi> Cc: hackers@freebsd.org Subject: Re: Rewriting pca(4) using finetimer(9) (was: Re: MPU401 now worksunder New Midi Driver Framework with a Fine Timer) Message-ID: <2231.931507837@critter.freebsd.dk> In-Reply-To: Your message of "09 Jul 1999 11:03:00 %2B0300." <86k8sajlmz.fsf@not.demophon.com>
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But shouldn't you still be able to use the timer in the local apic ? In message <86k8sajlmz.fsf@not.demophon.com>, Ville-Pertti Keinonen writes: > >phk@critter.freebsd.dk (Poul-Henning Kamp) writes: > >> Somebody should study the abilities of the on-cpu APIC for this >> for pentium ff. machines. > >The local APIC would work very nicely, but I'm not sure that you can >enable it reliably in a non-SMP configuration. AFAIK most BIOSes >don't provide an MP config at all unless you have multiple CPUs >present. If you don't have an MP config, you can't set up the >redirection tables. > >And if you have a non-SMP chipset, you can't route interrupts at all, >since you won't have an APIC bus on your motherboard or an I/O APIC >for the real interrupts. > >It's been a while since I looked at the documentation, but it *might* >be possible that the local APIC timers would work without using APIC >interrupt routing. IIRC the timers are simply programmed with the IDT >vector number to generate as an interrupt. > -- Poul-Henning Kamp FreeBSD coreteam member phk@FreeBSD.ORG "Real hackers run -current on their laptop." FreeBSD -- It will take a long time before progress goes too far! To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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