IO memory read from /proc/vmcore leads to hang.

Maxim Uvarov muvarov at
Fri Jul 22 04:11:05 PDT 2016

I might be wrong but as I remember powerpc32 is deprecated in
kexec-tools and all code use ppc64 directory even for 32 bit code...

2016-07-21 23:04 GMT+03:00 Daniel Walker <danielwa at>:
> On 07/21/2016 12:33 PM, Maxim Uvarov wrote:
>> 2016-07-21 18:19 GMT+03:00 Daniel Walker <danielwa at>:
>>>   There appears to be no code which checks what is or is not System ram,
>>> there is nothing that checks the device tree to see what is IO memory,
>>> and
>>> nothing reads /proc/iomem .. So AFAIK nothing cares if it's IO memory, or
>>> system ram, and there's no method to config things to skip any memory in
>>> the
>>> system, except in makedumpfile which can skip symbols not IO memory.
>> Daniel,  unfortunately it's long time for me when I looked to powerpc
>> code. But I just
>> checked that here:
>> kexec-tools-2.0.6/kexec/arch/ppc64/kexec-ppc64.c
>> is probably what you need.
> I have a powerpc32 .. In the powerpc64 file I only see something called
> "reserved-ranges" which may do what I want, however, that doesn't exist in
> the 32bit version.  It appers the reserved-ranges is used by OPAL firmware ,
> which I don't have. There doesn't appear to be anything generic in ppc64 to
> exclude device IO memory.
> Daniel

Best regards,
Maxim Uvarov

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