Date: 09 Jul 1999 11:03:00 +0300 From: Ville-Pertti Keinonen <will@iki.fi> To: phk@critter.freebsd.dk (Poul-Henning Kamp) 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: <86k8sajlmz.fsf@not.demophon.com> In-Reply-To: phk@critter.freebsd.dk's message of "8 Jul 1999 18:35:19 %2B0300" References: <199907081527.BAA04078@godzilla.zeta.org.au> <2663.931447908@critter.freebsd.dk>
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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. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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