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

[Florian Fainelli <florian@openwrt.org>]

Hello,

Le 16/04/2011 17:21, Philby John a écrit :
> 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

strip can be told to only strip a particular section, e.g: 
$(TARGET_CROSS)strip -R .notes

like David, I prefer this option rather than modifying the linker script.
--
Florian