Re: [Xenomai-help] compiling xenomai on x86_64

[Jan Kiszka <kiszka@domain.hid>]

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Gilles Chanteperdrix wrote:
> Jan Kiszka wrote:
>  > Gilles Chanteperdrix wrote:
>  > > Jan Kiszka wrote:
>  > >  > I just analysed this further: the problem disappears when I manually
>  > >  > remove any "-I<path-to-kernel-includes>" from the makefiles. Seems to be
>  > >  > the well-known user space include issue again... ;)
>  > > 
>  > > I tried to compile every kernel arch/i386 has a patch for with gcc 2.95,
>  > > 3.3 and 3.4, and I saw no issue with inclusions of kernel headers
>  > > from user-space. At all.
>  > 
>  > I think you were lucky. As far as I remember, it is generally no good
>  > idea to include kernel header for userspace compilation as long as you
>  > do not _exactly_ know (or test) what they bring with them. Some
>  > structures or defines locate in different headers under /usr/include
>  > compared to some kernel tree. So, if you are not lucky, you drag those
>  > definitions in twice - see below.
>  > 
>  > > 
>  > > So, there is definitely something you are doing differently from me. 
>  > > If this issue is different from the '-m32' flag issue, could you please
>  > > fill a bug report, and this time, attach the exact procedure you are
>  > > following to compile (whether in-tree, or out-of-tree, whether using
>  > > configure or Kconfig, everything that would allow someone to ), the
>  > > .config and .xeno_config files you used, in order for me to be able to
>  > > reproduce the problem you observed ?
>  > > 
>  > 
>  > As I'm not sure if you can reproduce it easily without my environment
>  > (that damn x86_64 gcc4 on SuSE10), I digged a little bit deeper, and
>  > here is a new theory:
>  > 
>  > The compilation fails in skins/native/libs/task.c (there exist similar
>  > files in other skins as well). The error: structures in
>  > <linux>/include/asm/sigcontext.h are being redefined. Unfortunately, gcc
>  > does not tell me where the first definition was. But here is my finding:
>  > commenting out #include <signal.h> in libs/task.c makes that error
>  > disappear. Following the include chain of /usr/include/signal.h
>  > (userspace headers...), you get to /usr/include/bits/sigcontext.h.
> 
> I still do not get it: you are compiling on x86_64, so headers in
> /usr/include are for x86_64, not ia32. Are you sure you do not need some

They are for both. You can compile some helloworld64 by calling gcc
without arguments or as easily a helloworld32 by running "gcc -m32" -
all on the same box withouth additional cross-tool stuff.

> glibc-ia32-cross-devel package, or something like that ? The kernel does
> not have these problems, since it is compiled with -ffreestanding.

...and it does not include user space headers.

> 
> Are you able to compile an ia32 user-space  hello world for example ?
> 

Yes, see above.

Jan

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