From owner-freebsd-current@FreeBSD.ORG Wed Sep 29 11:37:18 2010 Return-Path: Delivered-To: freebsd-current@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A172F1065675; Wed, 29 Sep 2010 11:37:18 +0000 (UTC) (envelope-from avg@icyb.net.ua) Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140]) by mx1.freebsd.org (Postfix) with ESMTP id B5A3F8FC16; Wed, 29 Sep 2010 11:37:17 +0000 (UTC) Received: from porto.topspin.kiev.ua (porto-e.starpoint.kiev.ua [212.40.38.100]) by citadel.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id OAA25590; Wed, 29 Sep 2010 14:37:16 +0300 (EEST) (envelope-from avg@icyb.net.ua) Received: from localhost.topspin.kiev.ua ([127.0.0.1]) by porto.topspin.kiev.ua with esmtp (Exim 4.34 (FreeBSD)) id 1P0uyJ-0003Tw-PL; Wed, 29 Sep 2010 14:37:15 +0300 Message-ID: <4CA324EB.4040500@icyb.net.ua> Date: Wed, 29 Sep 2010 14:37:15 +0300 From: Andriy Gapon User-Agent: Mozilla/5.0 (X11; U; FreeBSD amd64; en-US; rv:1.9.2.9) Gecko/20100918 Lightning/1.0b2 Thunderbird/3.1.4 MIME-Version: 1.0 To: Alexander Motin References: <201009291207.53146.naylor.b.david@gmail.com> <4CA317BA.8070903@FreeBSD.org> In-Reply-To: <4CA317BA.8070903@FreeBSD.org> X-Enigmail-Version: 1.1.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: "freebsd-current@freebsd.org" , David Naylor Subject: Re: Safe-mode on amd64 broken X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 29 Sep 2010 11:37:18 -0000 on 29/09/2010 13:40 Alexander Motin said the following: > Hi. > > David Naylor wrote: >> Trying to boot a recent (sep 23) amd64 kernel in safe-mode fails with ``panic: >> No usable event timer found!''. This occurs on two (all my) machines. This >> has been a persistent problem since the introduction of the event timer code. > > I've reproduced the problem. > > The reason is that all (or at least most) of devices (both PCI and ISA), > including only available in that mode i8254 and RTC timers, failed to > allocate their interrupts. While reported message is indeed related to > event timer code, problem IMHO doesn't. While without this panic system > could boot without any alive timer, I have doubts that it would be > functional without timers, USB, network and disk controllers. > > Problems seems to be the same if I am trying to boot without ACPI. > It's interesting to see what the "Safe Mode" really is: dup bootsafekey @ = if s" arch-i386" environment? if drop s" acpi_load" unsetenv s" 1" s" hint.acpi.0.disabled" setenv s" 1" s" loader.acpi_disabled_by_user" setenv s" 1" s" hint.apic.0.disabled" setenv then s" 0" s" hw.ata.ata_dma" setenv s" 0" s" hw.ata.atapi_dma" setenv s" 0" s" hw.ata.wc" setenv s" 0" s" hw.eisa_slots" setenv s" 1" s" hint.kbdmux.0.disabled" setenv 0 boot Not sure if disabling ACPI on modern hardware is a good idea. Even more unsure about disabling APIC. Makes me wonder what this could be useful for. Perhaps, these are just leftovers from times were ACPI, APIC (and ATA DMA) were all new and unproven things. -- Andriy Gapon