From owner-freebsd-hackers Fri Jul 9 1:12:17 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from critter.freebsd.dk (critter.freebsd.dk [212.242.40.131]) by hub.freebsd.org (Postfix) with ESMTP id 6E8C514C19 for ; Fri, 9 Jul 1999 01:12:09 -0700 (PDT) (envelope-from phk@critter.freebsd.dk) Received: from critter.freebsd.dk (localhost [127.0.0.1]) by critter.freebsd.dk (8.9.3/8.9.2) with ESMTP id KAA02233; Fri, 9 Jul 1999 10:10:38 +0200 (CEST) (envelope-from phk@critter.freebsd.dk) To: Ville-Pertti Keinonen 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) In-reply-to: Your message of "09 Jul 1999 11:03:00 +0300." <86k8sajlmz.fsf@not.demophon.com> Date: Fri, 09 Jul 1999 10:10:37 +0200 Message-ID: <2231.931507837@critter.freebsd.dk> From: Poul-Henning Kamp Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG 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