Date: Wed, 25 Jan 2012 11:44:21 +0200 From: Dirk Kotze <dk@Nanoteq.com> To: "'freebsd-questions@freebsd.org'" <freebsd-questions@freebsd.org> Subject: RE: Makeopts DEBUG=-g kernel option Message-ID: <F46C10D2F60F034BB106EAB4CD7E833C7A463EFBCD@ntq-ex.nanoteq.co.za> In-Reply-To: <F46C10D2F60F034BB106EAB4CD7E833C7A463EFBBF@ntq-ex.nanoteq.co.za> References: <F46C10D2F60F034BB106EAB4CD7E833C7A463EFBBF@ntq-ex.nanoteq.co.za>
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[-- Attachment #1 --] Hi again Just some feedback - it seems that I have isolated the problem below with the help of a 2005 post by John Nielsen to freebsd-questions (http://lists.freebsd.org/pipermail/freebsd-sparc64/2005-August/003423.html). I have isolated the problem as being caused by the compiler optimization flags, specifically the "-O2 -pipe" flags (the default flags used when "makeoptions DEBUG=-g" is not specified in the kernel configuration). I have proved that the DEBUG flag per se has nothing to do with it by removing it, and then adding makeoptions COPTFLAGS="-O -pipe" to the kernel config. This boots fine. Funny though, the exact original kernel used (without DEBUG and compiled with -O2) works fine on other hardware (e.g. the Tyan Tank G20 B5211 motherboard with an Intel Core2Duo CPU). It only fails on the WADE-8020 board. It must be some specific hardware driver used on the WADE-8020 motherboard that breaks when compiled with -O2. If anyone has suggestions as to how I can trace the problem further (so that I can log a bug with the BSD community), this will be appreciated. Hopefully I can ensure that a future user does not struggle with the same problem I did. As always, thanks for the help. Regards, Dirk Kotze Developer > From: Dirk Kotze > Sent: Monday, January 23, 2012 4:27 PM > To: 'freebsd-questions@freebsd.org' > Subject: Makeopts DEBUG=-g kernel option > > Hi there > > I'm experiencing the following problem: All is well when I boot the standard FreeBSD 8.2 GENERIC kernel. The moment > however when I comment out the line the line below, the kernel hangs upon boot after detecting the em0 device (the > motherboard has 2 Intel 8257x dual Gigabit Ethernet cards). > makeopts DEBUG=-g > > I'm using FreeBSD 8.2 on a WADE-8020 motherboard with an Intel QM57 chipset and Intel Core i5 CPU. > > The reason I'm trying to remove debugging options from the kernel is that I am trying to make the kernel footprint > smaller. > > This leaves me with a few questions: > 1) What are the risks/drawbacks/advantages of leaving debugging symbols in the kernel? > 2) Why would debug symbols (of all things!) make the difference between a working and non-working kernel? > 3) Does this point in the direction of some other (more serious problem perhaps?) with the hardware and/or other > kernel drivers? > > Thanks so much for any assistance. > > Regards, > Dirk Kotze > Developer > > > Tel: +27 12 672 7281 > Fax: +27 12 665 1343 > Postal: P.O. Box 7991, Centurion, 0046 > Physical: 1 Pieter street, Highveld Park, Centurion > Important Notice: This e-mail and its contents are subject to the Nanoteq (Pty) Ltd e-mail legal notice available at: http://www.nanoteq.com/corp_profile/disclaimer.asp Important Notice: This e-mail and its contents are subject to the Nanoteq (Pty) Ltd e-mail legal notice available at: http://www.nanoteq.com/corp_profile/disclaimer.asp [-- Attachment #2 --] The message does not contain any threats AVG for MS Exchange Server (10.0.1416 - 2109/4756)
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