Re: [PATCH] MIPS: Octeon: add option to ignore PT_NOTE section

[Philby John <pjohn@mvista.com>]

On 04/15/2011 09:57 PM, David Daney wrote:
> On 04/15/2011 01:55 AM, Philby John wrote:
>> On 04/15/2011 01:54 PM, Florian Fainelli wrote:
>>> Hello,
>>>
>>> On Wednesday 13 April 2011 19:38:02 David Daney wrote:
>>>> On 04/13/2011 09:07 AM, philby john wrote:
>>>>> From: Philby John<pjohn@mvista.com>
>>>>
>>>> ^^^^^^^^ I believe that statement to be not entirely correct.
>>>>
>>>> Perhaps you should change it to something like:
>>>> From: David Daney<ddaney@caviumnetworks.com>
>>>>
>>>>> Date: Wed, 13 Apr 2011 20:46:32 +0530
>>>>> Subject: [PATCH] MIPS: Octeon: add option to ignore PT_NOTE section
>>>>>
>>>>> Some early Octeon bootloaders cannot process PT_NOTE program
>>>>> headers as reported in numerous sections of the web, here is
>>>>> an example http://www.spinics.net/lists/mips/msg37799.html
>>>>> Loading usually fails with such an error ...
>>>>> Error allocating memory for elf image!
>>>>>
>>>>> The work around usually is to strip the .notes section by using
>>>>> such a command $mips-gnu-strip -R .notes vmlinux -o fixed-vmlinux
>>>>> It is expected that the vmlinux image got after compilation be
>>>>> bootable. Add a Kconfig option to ignore the PT_NOTE section.
>>>
>>> Do we really want this to be in the kernel? In my opinion, this is a
>>> fixup
>>> which distributions should be aware of, but not necessarily take
>>> place here in
>>> the kernel Makefiles.
>>
>> You are right in one way. But as an OS vendor company we will definitely
>> include this patch in our distribution. This incident has been reported
>> many a times and its a pain to see the image not boot up, throw up an
>> error, with the user having to search the work around on the web. What
>> we are trying to do is save all that trouble. If it can be fixed why not
>> fix it.
>>
> 
> I don't care one way or another.  We too (perhaps one and the same...)
> provide kernels to our SDK customers with the patch applied.
> 
> An alternative approach would be to put the $(CROSS_COMPILE)strip
> command into the arch/mips/Makefile.

I doubt that's any good, strip also removes debug symbols along with the
notes section and I am not aware of a specific command to strip just the
PT_NOTE section. Just these lines of code seem to get the job done
though ...

+#ifndef CONFIG_DISABLE_ELF_NOTE_HEADER
      NOTES :text :note
+#else
+    NOTES :text
+#endif

Regards,
Philby