[OE-core] [PATCH 2/2] udev: enable multilib support

[Koen Kooi]

Op 5 apr. 2013, om 16:34 heeft Richard Purdie <richard.purdie at linuxfoundation.org> het volgende geschreven:

> On Fri, 2013-04-05 at 16:29 +0300, Alex Damian wrote:
>> On udev-184 they changed the default location from /sbin/
>> to /lib/udev/ and I kept same as the upstream is.
> 
> Firstly, I know some people did ask me questions offlist about this and
> I probably gave misleading answers. I thought this was a problem with
> the location of the rules directory initially. We need to have one rules
> directory regardless of multilibs.
> 
> Binaries however are a very different question. The multilib code we
> have in OE is complex and does make some assumptions about layout, not
> least as we have to interface into several package managers and also
> work with all their assumptions. The situation is that:
> 
> * library files are expected to go into /libX
> * binaries are expected to go into the usual bin/sbin dirs
> * files in /etc, /usr/share and other similar directories are expected 
>  to be identical
> * We have sanity tests which check for these things
> 
> The package managers are taught to let certain packages "win" in
> bin/sbin and to error if overlapping files outside this are not
> identical.
> 
> It therefore follows that we would have to start adding exceptions to
> this code if we have potential for both 32 bit and 64 bit /lib/udev/
> binaries. We'd also have to add rules about which one would be expected
> to "win" under which circumstances and so on.
> 
> To me, the simplest solution here is to point libexec dir at /sbin so
> that we have /sbin/udev/ since this then works with the various multilib
> rules. It means a user can install the 64 bit and 32 bit multilibs for
> udev in parallel (for libudev for example) and that things should all
> work correctly.
> 
> I appreciate upstream don't agree with that approach but equally they
> don't have the generic multilib support we have to worry about. Hacking
> the multilib code to pieces just to match upstream in this case is going
> to be a lot more painful, I appreciate its the not optimal solution
> though.


FWIW, the udev *libraries* (libudev, libgudev, etc) go in $prefix/lib64 on 64 bit machines, the udev *binaries* into /lib. So multi*lib* should work.