Re: [Xenomai] Raspberry and Beaglebone patches

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

On 05/13/2013 01:20 PM, Stephan Kappertz wrote:

> Am 13.05.2013 um 12:37 schrieb Stephan Kappertz:
> 
>> Am 10.05.2013 um 19:02 schrieb Gilles Chanteperdrix:
>>
>>> On 05/10/2013 06:48 PM, Gilles Chanteperdrix wrote:
>>>
>>>> On 05/10/2013 06:40 PM, Stephan Kappertz wrote:
>>>>
>>>>>>>>
>>>>>>>
>>>>>>> I'm using your git repository directly. Applied my post.patch and
>>>>>>> compiled the kernel. So this is 3.8.0. Looks like my Xenomai user
>>>>>>> space compile was broken. Still working on fixing it.
>>>>>>
>>>>>>
>>>>>> What options did you pass to the configure script?
>>>>>>
>>>>>>
>>>>>> -- 
>>>>>>                                                              Gilles.
>>>>>>
>>>>>
>>>>> ../configure --target=arm-buildroot-linux-uclibcgnueabi --host=arm-buildroot-linux-uclibcgnueabi --build=i686-pc-linux-gnu --prefix=/usr --exec-prefix=/usr --sysconfdir=/etc --program-prefix="" --enable-static --enable-shared  CFLAGS="-march=armv7-a -mfpu=vfp3" LDFLAGS="-march=armv7-a -mfpu=vfp3" --includedir=/usr/include/xenomai/
>>>>>
>>>>> This is a buildroot build.
>>>>
>>>>
>>>> Could you:
>>>> - tell me what version of gcc, binutils, etc... you use?
>>>> - show me a disassembly of the xeno_bind_skip_opt function in libxenomai.so?
>>>> - instrument the function xeno_sigill_handler in
>>>> src/skins/common/bind.c to see if you are indeed taking the SIGILL signal?
>>>
>>>
>>> Sorry, you do not take the SIGILL handler, please instrument
>>> xeno_bind_skin_opt to print the value of "muxid" returned by the
>>> XENOMAI_SYSBIND system call.
>>>
>>> -- 
>>>                                                               Gilles.
>>>
>>
>>
>> Ok, here's the compiler spec:
>>
>> $ arm-linux-gnueabi-gcc -v
>> Using built-in specs.
>> COLLECT_GCC=arm-linux-gnueabi-gcc
>> COLLECT_LTO_WRAPPER=/usr/lib/gcc/arm-linux-gnueabi/4.6/lto-wrapper
>> Target: arm-linux-gnueabi
>> Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.6.3-1ubuntu5' --with-bugurl=file:///usr/share/doc/gcc-4.6/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.6 --enable-shared --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/arm-linux-gnueabi/include/c++/4.6.3 --libdir=/usr/lib --enable-nls --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --enable-plugin --enable-objc-gc --enable-multilib --disable-sjlj-exceptions --with-arch=armv7-a --with-float=softfp --with-fpu=vfpv3-d16 --with-mode=thumb --disable-werror --enable-checking=release --build=i686-linux-gnu --host=i686-linux-gnu --target=arm-linux-gnueabi --program-prefix=arm-linux-gnueabi- --includedir=/usr/arm-linux-gnueabi/include --with-headers=/usr/arm-linux-gnueabi/include --with-libs=/usr/arm-linux-gnueabi/lib

>> Thread model: posix
>> gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5)
>>
>> Binutils are 2.22:
>>
>> arm-linux-gnueabi-as -v
>> GNU assembler version 2.22 (arm-linux-gnueabi) using BFD version (GNU Binutils for Ubuntu) 2.22
>>
>>
>> Now what's interesting is: as soon as I am adding an instrumentation "fprintf(stdout, "Xenomai: xeno_bind_skin_opt muxid = %d\n", muxid);" to "static inline int xeno_bind_skin(unsigned skin_magic, const char *skin, const char *module)", binding succeeds and all xeno-test pass. The other option to get it work was:  declaring "int xeno_bind_skin(unsigned skin_magic, const char *skin, const char *module);" in bind.h and defining it in bind.c.
>>
>> If I'm only instrumenting xeno_bind_skin_opt(), I see that it never gets called in the original code.
>>
>> Do you still want to see the disassembly?
>>
>> -- Stephan
>>
> 
> Oops, sent you the wrong compiler spec. Xenomai libraries & tests are compiled with:
> 
> $ host/usr/bin/arm-buildroot-linux-uclibcgnueabi-gcc -v
> Using built-in specs.
> COLLECT_GCC=host/usr/bin/arm-buildroot-linux-uclibcgnueabi-gcc
> COLLECT_LTO_WRAPPER=/home/stephan/dev.ws.Centaurus_skappert/embedded/products/Carbon/AM335x/host/usr/libexec/gcc/arm-buildroot-linux-uclibcgnueabi/4.6.3/lto-wrapper
> Target: arm-buildroot-linux-uclibcgnueabi
> Configured with: /home/stephan/dev.ws.Centaurus_skappert/embedded/products/Carbon/AM335x/toolchain/gcc-4.6.3/configure --prefix=/home/stephan/dev.ws.Centaurus_skappert/embedded/products/Carbon/AM335x/host/usr --build=i686-pc-linux-gnu --host=i686-pc-linux-gnu --target=arm-buildroot-linux-uclibcgnueabi --enable-languages=c --with-sysroot=/home/stephan/dev.ws.Centaurus_skappert/embedded/products/Carbon/AM335x/host/usr/arm-buildroot-linux-uclibcgnueabi/sysroot --with-build-time-tools=/home/stephan/dev.ws.Centaurus_skappert/embedded/products/Carbon/AM335x/host/usr/arm-buildroot-linux-uclibcgnueabi/bin --disable-__cxa_atexit --enable-target-optspace --disable-libquadmath --disable-libgomp --with-gnu-ld --disable-libssp --disable-multilib --enable-tls --enable-shared --with-gmp=/home/stephan/dev.ws.Centaurus_skappert/embedded/products/Carbon/AM335x/host/usr --with-mpfr=/home/stephan/dev.ws.Centaurus_skappert/embedded/products/Carbon/AM335x/host/usr --with-mpc=/home/stephan/dev.ws
.Centaurus_skappert/embedded/products/Carbon/AM335x/host/usr --disable-nls --enable-threads --disable-decimal-float --with-float=soft --with-abi=aapcs-linux --with-arch=armv7-a --with-tune=cortex-a8 --disable-largefile --with-pkgversion='Buildroot 2013.02' --with-bugurl=http://bugs.buildroot.net/
> Thread model: posix
> gcc version 4.6.3 (Buildroot 2013.02) 
> 
> /dev.ws.Centaurus_skappert/embedded/products/Carbon/AM335x$ host/usr/bin/arm-buildroot-linux-uclibcgnueabi-as -v
> GNU assembler version 2.21.1 (arm-buildroot-linux-uclibcgnueabi) using BFD version (GNU Binutils) 2.21.1


Hi Stefan,

I have no other explanation than that the combination of the toolchain
you use with Xenomai code you use produces broken code.

The version of libnative.so generated with a similar toolchain
(codesourcery 2012.03) has three pointers in its .init_array section,
these are the pointers to the functions which are invoked upon library
startup:
frame_dummy
__init_xeno_interface
__init_native_tskey

The version of libnative.so you sent me has four pointers in its
.init_array section:
0x2458
0x2254
0x22b8
0x2308

I do not have the function names, I believe, because the binary you sent
me is stripped. However, 0x2308 looks like __init_xeno_interface, 0x2254
looks like __init_native_tskey, and 0x22b8 has the following disassembly:

    22b8:	e92d4008 	push	{r3, lr}
    22bc:	e59f3030 	ldr	r3, [pc, #48]	; 22f4 <free@plt+0x108>
    22c0:	e59f0030 	ldr	r0, [pc, #48]	; 22f8 <free@plt+0x10c>
    22c4:	e08f3003 	add	r3, pc, r3
    22c8:	e59f102c 	ldr	r1, [pc, #44]	; 22fc <free@plt+0x110>
    22cc:	e59f202c 	ldr	r2, [pc, #44]	; 2300 <free@plt+0x114>
    22d0:	e7930000 	ldr	r0, [r3, r0]
    22d4:	e08f1001 	add	r1, pc, r1
    22d8:	e59f3024 	ldr	r3, [pc, #36]	; 2304 <free@plt+0x118>
    22dc:	e08f2002 	add	r2, pc, r2
    22e0:	e08f3003 	add	r3, pc, r3
    22e4:	e5900000 	ldr	r0, [r0]
    22e8:	ebffff5f 	bl	206c <fprintf@plt>
    22ec:	e3a00001 	mov	r0, #1
    22f0:	ebffff99 	bl	215c <exit@plt>

Which means that it calls directly fprintf and exit, without even
calling xeno_bind_skin_opt. So, it looks like an "optimized" version of
__init_xeno_interface, assuming xeno_bind_skin_opt always return -1.

So, questions now:
- what commit in xenomai git are you using?
- could you try another toolchain ?

Regards.
-- 
                                                                Gilles.