Subject: Re: savecore/etc To: JR "Bob" Dobbs <> From: David
Jones <> List: current-users Date: 06/28/1995 19:07:51 > Now
what the hell do I do with this if I'm interested in finding out
exactly > what blew up?  Use gdb on the saved kernel image and
core?  Good question.  GDB likes user-land core files.  They
have a core header which gives the value of the PC and registers
at the time of the core.  A kernel core file is a raw dump of
physical memory.  You have 8 MB of RAM so you got an 8 MB core.
There is no core header.  Worse, this is _physical_ memory.  To
map it to kernel virtual space, you need an MMU table.  On most
machines, the MMU table is stored in core, so it's in that core
dump - somewhere.  The first thing a kernel hacker would do is
figure out what the MMU root pointers (or whatever they're
called in 386 land) were so the kernel's memory map could be
reconstructed based on the values in the core file.  Once you've
established that, you still don't have a PC value or anything.
The PC might be wr