[U-Boot] [PATCH] armv7: fix linker file for newer ld support

[Måns Rullgård]

Albert ARIBAUD <albert.aribaud at free.fr> writes:

> Le 02/11/2010 14:08, Steve Sakoman a écrit :
>> On Tue, Nov 2, 2010 at 12:48 AM, Albert ARIBAUD<albert.aribaud at free.fr>  wrote:
>>> Le 02/11/2010 05:05, Steve Sakoman a écrit :
>>>
>>>> I've been using gcc 4.3.3, so I haven't run into the issue that this
>>>> patch is attempting to fix.
>>>>
>>>> I tested this patch using gcc 4.3.3, and while it produces a usable
>>>> image, it causes the size of the image to grow from 227K to 433K!
>>>>
>>>> So perhaps we need a patch that uses a more restrictive wildcard.
>>>>
>>>> Steve
>>>
>>> Thanks for pointing this out, Steve. That'll go into V3 of my patch set I
>>> guess, as Alexander's patch derives from mine and I most probably hit the
>>> same size increase issue as he does.
>>>
>>> Wolfgang: that may mean the tx25 config file patch is unneeded. Stay tuned.
>>
>> I should have stated that I was using gcc 4.3.3 and binutils 2.18.50,
>> since indeed it does seem to be binutils related.
>>
>> I have had a couple of reports that the following patch works with
>> recent gcc/binutils without increasing the size of the binary.
>>
>> Could others check and report results?
>>
>> Steve
>>
>>
>> ARMV7: Fix build issue with recent versions of gcc/binutils
>> ---
>>
>> diff --git a/arch/arm/cpu/armv7/u-boot.lds b/arch/arm/cpu/armv7/u-boot.lds
>> index 88a0fec..e690b58 100644
>> --- a/arch/arm/cpu/armv7/u-boot.lds
>> +++ b/arch/arm/cpu/armv7/u-boot.lds
>> @@ -55,7 +55,7 @@ SECTIONS
>>   	}
>>   	. = ALIGN(4);
>>   	__rel_dyn_start = .;
>> -	.rel.dyn : { *(.rel.dyn) }
>> +	.rel.dyn : { *(.rel.*) }
>>   	__rel_dyn_end = .;
>>
>>   	__dynsym_start = .;
>
> Weird... This patch seems indeed more restrictive than mine, but the 
> input sections collected in .rel.dyn are actually the same for both.
>
> We can gain a bit less than 60k by overlapping .bss and .rel.dyn, but 
> certainly not 200k!
>
> OTOH, it happened during my 'cross-build' tests (using one chain's gcc 
> with another chain's ld) that the resulting u-boot was drastically 
> reduced; but I chalked that to my misusing of the build tools.
>
> Steve, can you indicate which toolchain excatly exhibits the 
> 230k-to-430k issue, and which board I should build?

The problem is that the first patch posted here places .rel.dyn after
.bss, so when dumping u-boot.img, all of .bss is included in the file.
Keeping it before .bss allows the flat binary to omit .bss as usual.

Using the patch quoted above, I get a working u-boot from all
combinations of gcc and binutils I cared to try, including gcc
4.5-linaro with binutils 2.20.1.

-- 
Måns Rullgård
mans at mansr.com