[U-Boot] [PATCH v2 3/6] cm-t35: add EEPROM module and pass Linux a serial number

[Albert ARIBAUD]

Le 17/02/2012 18:10, Tom Rini a écrit :
> On 02/17/2012 02:50 AM, Albert ARIBAUD wrote:
>> Hi Igor,
>>
>> Le 07/02/2012 09:01, Igor Grinberg a écrit :
>>> Hi Albert,
>>>
>>> On 02/07/12 00:56, Albert ARIBAUD wrote:
>>>> Le 09/01/2012 09:30, Nikita Kiryanov a écrit :
>>>>> On 01/05/2012 04:56 PM, Wolfgang Denk wrote:
>>>>>> Dear Igor Grinberg,
>>>>>>
>>>>>> In message<1325764937-7342-1-git-send-email-grinberg at compulab.co.il>
>>>>>> you wrote:
>>>>>>> From: Nikita Kiryanov<nikita at compulab.co.il>
>>>>>>>
>>>>>>> Add board specific EEPROM handling module,
>>>>>>> read the serial number from the EEPROM and pass it to Linux.
>>>>>> ...
>>>>>>
>>>>>>> * Fix strange linker warning: ".bss section overlaps previous
>>>>>>> sections"
>>>>>>> by changing the type of the eeprom_layout static global variable
>>>>>>> to int
>>>>>>> (probably this is a compiler bug).
>>>>>> Probably it is now. Did you inspect the linke rmap?
>>>>>
>>>>> u-boot.map shows the bss section aligning perfectly with the start of
>>>>> rel.dyn.
>>>>>
>>>>> The difference between the original "working" version and the version
>>>>> with the warning
>>>>> was an additional byte added by uchar eeprom_layout to the size of
>>>>> libcm_t35.o.
>>>>> This shouldn't be a problem because the bss section is followed by an
>>>>> ALIGN(4), but
>>>>> we decided to try changing eeprom_layout to an int and the problem
>>>>> went
>>>>> away.
>>>>> When we tried to define 4 uchars the problem reappeared.
>>>>>
>>>>> This suggests that this might be a compiler bug.
>>>>>
>>>>> There's been some discussion about this in the following threads:
>>>>> http://comments.gmane.org/gmane.comp.boot-loaders.u-boot/114646
>>>>> http://comments.gmane.org/gmane.comp.boot-loaders.u-boot/90723
>>>>> and we're not aware of any fix to the issue.
>>>>
>>>> Which prompted me to test --no-check-sections with CS 2009q1.
>>>> Adding it to LDFLAGS_u-boot does reduce the annoyance from errors to
>>>> a warning,
>>>> but there is no way to completely make it disappear.
>>>
>>> So the conclusion is still a tool chain bug, right?
>>> Probably it doesn't hurt besides the annoying warning.
>>
>> Sorry for being slow.
>>
>> Yes, it seems to be a toolchain bug and limited to a spurious warning.
>> However, spurious warnings are always a pain when doing a MAKEALL arm,
>> because the board is listed among the unclean and failed builds and then
>> one must go through these individually and remember that this specific
>> warning is both unimportant and unavoidable.
>
> Have we gone and bugged any toolchain folks about what caused / fixed
> this problem so that perhaps we can option around it or otherwise squash
> this?

I haven't, as I work mostly with ELDK42 and occasionally recent (2010 
and later) CS and current Ubuntu-provided Linaro toolchains, and don't 
see the warning -- and I don't think toolchain providers will bother 
about warnings from old releases that do not still exist in current 
ones, just like we don't bother with issues present only in older 
version of U-Boot.

But if somebody on the list is using the current version of some 
toolchain that does emit this warning, then yes, they should indeed 
bring the issue to the toolchain provider, or at least raise their hand 
here.

Amicalement,
-- 
Albert.