[Buildroot] ld-linux.so.3 problem with external EABIhf toolchain

[Arnout Vandecappelle <arnout@mind.be>]

On 23/04/14 13:27, Will Newton wrote:
> On Wed, Apr 23, 2014 at 12:06 PM, Luca Ceresoli <luca@lucaceresoli.net> wrote:
>> Hi all, Thomas,
>>
>> I'm in the middle of updating a project from Buildroot 2013.08 to
>> 2013.11, but I hit a problem with the external toolchain installation.
>>
>> The project uses an external ARMv7 EABIhf toolchain (no multilib)
>> previously built with crosstool-NG, installed on the build host.
>>
>> Between 2013.08 and 2013.11 lies (*) this commit:
>>
>>>  commit 11ec38b6950cf3337b52fb97f27c2fd7c776c5c2
>>>  Author: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
>>>  Date:   Tue Oct 8 20:17:15 2013 +0200
>>>
>>>      toolchain-external: fix Linaro ARM toolchain support
>>>
>> ...
>>>
>>>  -LIB_EXTERNAL_LIBS+=ld*.so.* libc.so.* libcrypt.so.* libdl.so.*
>>> libgcc_s.so.* libm.so.* libnsl.so.* libresolv.so.* librt.so.* libutil.so.*
>>>  +LIB_EXTERNAL_LIBS+=libc.so.* libcrypt.so.* libdl.so.* libgcc_s.so.*
>>> libm.so.* libnsl.so.* libresolv.so.* librt.so.* libutil.so.*
>>>  +ifeq ($(BR2_ARM_EABIHF),y)
>>>  +LIB_EXTERNAL_LIBS+=ld-linux-armhf.so.*
>>>  +else
>>>  +LIB_EXTERNAL_LIBS+=ld*.so.*
>>>  +endif
>>
>> Here when an EABIhf toolchain is used, ld-2.13.so and ld-linux.so.3 are
>> not installed on the target. This is for Linaro toolchains.
>>
>> My toolchain is EABIhf, but ships ld-2.13.so and ld-linux.so.3.
>>
>> So the commit above breaks runtime execution of nearly every executable
>> (including busybox init), since no ld-linux is installed on the target.
>>
>> The following dirty hack solves my own use case:
>>
>>  ifeq ($(BR2_ARM_EABIHF),y)
>> -LIB_EXTERNAL_LIBS+=ld-linux-armhf.so.*
>> +LIB_EXTERNAL_LIBS+=ld-linux-armhf.so.* ld*.so.*
>>  else
>>  LIB_EXTERNAL_LIBS+=ld*.so.*
>>  endif
>>
>> I wonder which may be the best way to fix it properly without breaking
>> other toolchains.
>>
>> Is there a specific reason for having a different dynamic loader naming
>> in ARM EABIhf toolchains? Or is it just that, by coincidence, all
>> EABIhf toolchains supported by Buildroot (=Linaro) happen to do so?
> 
> Linaro toochains do this renaming of ld.so to support multilibs (in
> other words supporting both hard and soft float on the same system).
> It seems like it should be safe to install all ld*.so.* in either case
> but I am sure Thomas has thought about this a lot harder than I have!

 So probably a buildroot toolchain that is used as an external toolchain
would expose the same issue...

 Actually, it looks like there is no br-arm-*-gnueabihf toolchain on
http://autobuild.buildroot.net/toolchains, perhaps that should be added?

 Regards,
 Arnout


-- 
Arnout Vandecappelle                          arnout at mind be
Senior Embedded Software Architect            +32-16-286500
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