Shared library question

Shared library question

[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@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@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...

Thanks

n.b. I'm happy to share any of the recipes, I just left them out for brevity.

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

Re: Shared library question

[Max Krummenacher]

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@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@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".


Max





> 
> Thanks
> 
> n.b. I'm happy to share any of the recipes, I just left them out for brevity.
> 
> -- 
> ------------------------------------------------------------
> Gary Thomas                 |  Consulting for the
> MLB Associates              |    Embedded world
> ------------------------------------------------------------

Re: 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@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@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

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