Messages in this thread | | | Date | Fri, 5 Aug 2011 14:01:03 -0700 (PDT) | Subject | kdump: Trouble reading /dev/oldmem from capture kernel | From | "Seemanta Dutta" <> |
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Greetings kernel hackers,
I am trying to dump the raw memory from the /dev/oldmem device from within a kexec()'ed capture kernel. But it seems to be that I can only read 4k of data from /dev/oldmem. I am following the kdump documentation given in: http://www.mjmwired.net/kernel/Documentation/kdump/. And according to the documentation in the above link, /dev/oldmem *should* present the raw view of memory.
Some details about my scenario: 1. Production kernel panics, and I boot into the dump capture kernel without any issues.
2. Dump capture kernel provides two interfaces to access 'old' kernel memory (as per kdump dpcumentation): /dev/oldmem and /proc/vmcore. The latter works perfectly. But I am more interested in the raw memory, rather than the core file.
My expectation in this scenario was that I would be able to access entire physical RAM using the /dev/oldmem device. But turns out, I can't.
I would be grateful if anyone pointed out if I was doing something wrong or missing something.
This is happening over ARM. Could that have to do something with this ? Not sure if the ARM integration of KDUMP/KEXEC has something to do with it.
Your help would be greatly appreciated!
regards, Seemanta
--
Employee of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum
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