[yocto] Shared library question

[Gary Thomas]

On 2017-02-27 21:11, Max Krummenacher wrote:
> Hi
>
> Am Montag, den 27.02.2017, 15:03 +0100 schrieb Gary Thomas:
>> I trying to create a package am335x-pru-support which creates a
>> shared library used by another package pru-examples.  The library
>> files installed with am335x-pru-support are (from <BUILD>/image)
>> -rwxr-xr-x 4 gthomas gthomas 17074 Feb 27 13:40 usr/lib/libprussdrv.a
>> lrwxrwxrwx 1 gthomas gthomas    16 Feb 27 13:40 usr/lib/libprussdrv.so -> libprussdrv.so.1
>> lrwxrwxrwx 1 gthomas gthomas    18 Feb 27 13:40 usr/lib/libprussdrv.so.1 -> libprussdrv.so.1.0
>> -rwxr-xr-x 1 gthomas gthomas 22092 Feb 27 13:40 usr/lib/libprussdrv.so.1.0
>> -rw-r--r-- 4 gthomas gthomas 8074 Feb 27 13:40 usr/include/pruss/prussdrv.h
>> -rw-r--r-- 4 gthomas gthomas 4286 Feb 27 13:40 usr/include/pruss/pruss_intc_mapping.h
>>
>> These files are split by the packager as:
>> gthomas at europa:packages-split$ find am335x-pru-support | sort
>> am335x-pru-support
>> am335x-pru-support/usr
>> am335x-pru-support/usr/lib
>> am335x-pru-support/usr/lib/libprussdrv.so.1
>> am335x-pru-support/usr/lib/libprussdrv.so.1.0
>> gthomas at europa:packages-split$ find am335x-pru-support-dev | sort
>> am335x-pru-support-dev
>> am335x-pru-support-dev/usr
>> am335x-pru-support-dev/usr/include
>> am335x-pru-support-dev/usr/include/pruss
>> am335x-pru-support-dev/usr/include/pruss/prussdrv.h
>> am335x-pru-support-dev/usr/include/pruss/pruss_intc_mapping.h
>> am335x-pru-support-dev/usr/lib
>> am335x-pru-support-dev/usr/lib/libprussdrv.so
>>
>> These files get staged correctly to pru-examples recipe-specific-sysroot
>> and I can build and link against them, using DEPENDS="am335x-pru-support".
>> The problem is that when my build (target recipe) uses
>>    $(CC) my_target_program.c $(LDFLAGS) -lprussdrv
>> it gets satisfied by /usr/lib/libprussdrv.so and not /usr/lib/libprussdrv.so.1
>> This in turn appears to keep the pru-examples package from having
>> a runtime dependency against the am335x-pru-support package and the
>> necessary library file does not end up on my target.
>>
>> I've tried to work through this, following many recipes as examples,
>> e.g. meta/recipes-multimedia/libogg (pattern for am335x-pru-support)
>> and meta/recipes-multimedia/flac (pattern for pru-examples).  The
>> libogg/flac combo works correctly, mine does not :-(
>>
>> Any pointers on what I might be doing wrong?  I'm so close to getting
>> this stuff going, it's just the packaging that's going to claim the
>> last hairs from my head...
>
> When linking a shared object file you have to pass the linker a soname which adds compatible version
> information into the share object file.
> Have a look here:
> http://git.yoctoproject.org/cgit/cgit.cgi/meta-fsl-arm/commit/recipes-bsp?id=7ff327a4e3e8e19d1e3f848
> 865b6b27ba9f6250b
> http://tldp.org/HOWTO/Program-Library-HOWTO/shared-libraries.html
>
>
> Alternatively you can drop the libprussdrv.so.1 and libprussdrv.so.1.0, and force with FILES... the
> libprussdrv.so into the not -dev package.
> Probably you would also want to INSANE_SKIP_${PN} = "dev-so".

Perfect, that worked a treat!

Thanks

-- 
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Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
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