Re: [Xenomai] Raspberry Pi + Xenomai doesn't compile

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

On Thu, May 21, 2015 at 04:48:56PM -0400, Lennart Sorensen wrote:
> On Thu, May 21, 2015 at 10:18:11PM +0200, Marc Marí wrote:
> > Hello
> > 
> > I'm trying to put Xenomai 2.6.4 on top of a Raspberry Pi model B with
> > kernel version 3.8.13. In theory, it should be straightforward, but I
> > don't get it to compile, and I don't know if I'm missing something
> > vital or something is broken.
> > 
> > This is what I executed:
> > 
> > $ git clone git@github.com:raspberrypi/linux.git
> > $ mv linux rpi-xenomai
> > $ git checkout rpi-3.8.y
> > $ patch -p1 -i \
> > ../xenomai-2.6.4/ksrc/arch/arm/patches/raspberry/ipipe-core-3.8.13-raspberry-pre-2.patch
> > $ ../xenomai-2.6.4/scripts/prepare-kernel.sh --arch=arm --linux=./ \
> > --adeos=../xenomai-2.6.4/ksrc/arch/arm/patches/ipipe-core-3.8.13-arm-4.patch
> > $ patch -p1 -i \
> > ../xenomai-2.6.4/ksrc/arch/arm/patches/raspberry/ipipe-core-3.8.13-raspberry-post-2.patch
> > $ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- bcmrpi_defconfig
> > $ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf-
> > 
> > I get this output:
> > 
> > kernel/ipipe/core.c: In function ‘ipipe_probe_kernel_read’:
> > kernel/ipipe/core.c:1748:2: error: implicit declaration of function
> > ‘get_fs’ [-Werror=implicit-function-declaration]
> >   mm_segment_t old_fs = get_fs();
> >   ^
> > kernel/ipipe/core.c:1750:2: error: implicit declaration of function
> > ‘set_fs’ [-Werror=implicit-function-declaration]
> >   set_fs(KERNEL_DS);
> >   ^
> > kernel/ipipe/core.c:1750:9: error: ‘KERNEL_DS’ undeclared (first use in
> > this function)
> >   set_fs(KERNEL_DS);
> >          ^
> > kernel/ipipe/core.c:1750:9: note: each undeclared identifier is
> > reported only once for each function it appears in
> > kernel/ipipe/core.c:1753:2: error: implicit declaration of function
> > ‘__copy_from_user_inatomic’ [-Werror=implicit-function-declaration]
> >   ret = __copy_from_user_inatomic(dst,
> >   ^
> > kernel/ipipe/core.c: In function ‘ipipe_probe_kernel_write’:
> > kernel/ipipe/core.c:1767:9: error: ‘KERNEL_DS’ undeclared (first use in
> > this function)
> >   set_fs(KERNEL_DS);
> >          ^
> > kernel/ipipe/core.c:1770:2: error: implicit declaration of function
> > ‘__copy_to_user_inatomic’ [-Werror=implicit-function-declaration]
> >   ret = __copy_to_user_inatomic((__force void __user *)dst, src, size);
> >   ^
> > cc1: some warnings being treated as errors
> > scripts/Makefile.build:307: recipe for target 'kernel/ipipe/core.o'
> > failed
> > make[2]: *** [kernel/ipipe/core.o] Error 1
> > scripts/Makefile.build:454: recipe for target 'kernel/ipipe' failed
> > make[1]: *** [kernel/ipipe] Error 2
> > Makefile:791: recipe for target 'kernel' failed
> > make: *** [kernel] Error 2
> > 
> > 
> > I tried by including asm/uaccess.h, which solved the issue. But the
> > kernel doesn't boot, and there is no message. It just hangs.
> > 
> > I tried the same kernel without Xenomai patch, and it compiles and
> > boots without problem.
> 
> Did you enable IPIPE in the config?  After all bcmrpi_defconfig probably
> does NOT include IPIPE config, and most releases of ipipe don't compile
> if you disable IPIPE support.  I have only ever seen recent versions
> actually be able to compile with CONFIG_IPIPE=n.

That statement is simply not true. Most I-pipe patched kernel
compile with IPIPE off, but you happened to find one that did not.
Please stop spreading this misconception.

-- 
					    Gilles.