Date: Sat, 3 Feb 1996 22:29:29 +0100 (MET) From: J Wunsch <j@uriah.heep.sax.de> To: scrappy@ki.net (Marc G. Fournier) Cc: hackers@FreeBSD.ORG Subject: Re: How to use DDB to debug a boottime panic? Message-ID: <199602032129.WAA21349@uriah.heep.sax.de> In-Reply-To: <Pine.BSF.3.91.960203143227.10739D-100000@ki.net> from "Marc G. Fournier" at Feb 3, 96 02:40:22 pm
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As Marc G. Fournier wrote: > So, I ask here...how do I use DDB? I've read through the man > page for DDB, and got absolutely no where with it. Print out the man page, you'll need it. > being able to use DDB. From the man page, I had assumed that doing something > like: > > print $scbus x/x scbus,10 However p $eax when you wanna know the value of %eax. DDB doesn't have type definitions, it can only handle basic types. > On top of that, I somehow need to step back to get the value > before the call to scsi_attachdevs(), but...'step -1' doesn't do that > either :( Naturally. How should stepping backwards work? You need to set a breakpoint earlier. Remember the -d boot flag (RTFM boot(8)). > If found the GDB examples in the FAQ (or handbook) to be enough to > get me stepping through the kernel and getting the data that was requested, > but have yet to find a similar example for DDB. Look into the handbook again, i once wrote an introduction to using DDB, it is in the section about ``Kernel debugging''. -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-)
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