HOWTO? Debug the boot sequence...
What I want to be able to do is build a kernel with a console mode debugger, so I can find out where the kernel is really dying.
Can this be done?
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I have built 2.2.0-pre5 for Jensen. I am having trouble booting it in two different ways and I'd like to hear any ideas about what's wrong and how to diagnose or fix the problems.
Ultimately the goal is to successfully boot the Jensen with a 2.2.0-preX kernel. I'm building pre7 now.
With pre5, the kernel boots up to a report 'Partition Check', lists the available partitions and halts. The halt causes a switch to the SRM blue screen console mode, which removes all trace of the kernel boot messages, so I'm not sure the partition check is the last thing, it's just the last thing I've seen.
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The second problem I'm having is using aboot to load the pre5 kernel from an ext2 partition. So far I have been able to use swriteboot to get aboot to load the kernel as 0/a. I can't get aboot to load the pre5 kernel as 1/vmtest.gz, which causes the error 'unzip: unknown compression method'. Once this error occurs, I must reload aboot from the SRM console before it will successfully load anything.
Its possible that aboot is causing both problems, in that it may not really be loading the whole kernel as 0/a, so the kernel trips memory it expects to be the kernel, but isn't, and executes a bogus halt instruction.
I'd like to make a debuggable version of aboot, to find out what's causing the error. The problem I'm having here is it's designed to be a standalone program, so I'd need a console mode debugger compiled in, which is the same thing I want to do for the kernel.
Anyone done this sort of thing? Is my only choice to sprinkle printf's through the aboot code?
Any feedback welcome.
Thanks.
- Peter Mott
Peter Mott | mailto:mott@mathworks.com | Voice: 508.647.7375
| http://www.mathworks.com | FAX: 508.647.7002
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