Re: [Xenomai-help] Xenomai on AT91SAM9260

[Philippe Gerum <rpm@xenomai.org>]

Gilles Chanteperdrix wrote:
> Hans Søndergaard (HSO) wrote:
>  > Hi,
>  > 
>  > Thanks for the answer.
>  > We are now trying to install Xenomai 2.4.3 using Linux 2.6.24 on AT91SAM9260,
>  > but have a problem:
>  > 
>  > Is it possible to disable the building of the posix skin when
>  > configuring the user space libraries for Xenomai?
>  > 
>  > I have tried --disable-posix-skin, but this had no effect.
>  > 
>  > The reason why I ask is that the building of src/skins/posix/init.c
>  > fails like this:
>  > 
>  > [stk@domain.hid posix]$ arm-linux-uclibc-gcc -DHAVE_CONFIG_H -I. -I../../../src/inc
>  > lude -I../../../../xenomai-2.4.3/src/skins/posix -O2 -D_GNU_SOURCE -D_REENTRANT
>  > -Wall -pipe -march=armv5 -D__XENO__ -D__IN_XENO__ -Wstrict-prototypes -I../../..
>  > /../xenomai-2.4.3/include -I../../../../xenomai-2.4.3/include/posix -MT libpthre
>  > ad_rt_la-init.lo -MD -MP -MF .deps/libpthread_rt_la-init.Tpo -c ../../../../xeno
>  > mai-2.4.3/src/skins/posix/init.c  -fPIC -DPIC -o .libs/libpthread_rt_la-init.o
>  > In file included from ../../../src/include/asm/xenomai/atomic.h:78,
>  >                  from ../../../../xenomai-2.4.3/include/nucleus/system.h:27,
>  >                  from ../../../src/include/asm/xenomai/system.h:135,
>  >                  from ../../../../xenomai-2.4.3/include/nucleus/types.h:40,
>  >                  from ../../../../xenomai-2.4.3/include/nucleus/queue.h:25,
>  >                  from ../../../../xenomai-2.4.3/include/nucleus/timebase.h:30,
>  >                  from ../../../../xenomai-2.4.3/include/nucleus/timer.h:27,
>  >                  from ../../../../xenomai-2.4.3/include/nucleus/thread.h:26,
>  >                  from ../../../../xenomai-2.4.3/include/posix/pthread.h:150,
>  >                  from /home/stk/brick/mb9200/buildroot/build_arm/staging_dir/bin
>  > -ccache/../lib/gcc/arm-linux-uclibc/4.1.1/../../../../arm-linux-uclibc/sys-inclu
>  > de/bits/uClibc_mutex.h:16,
>  >                  from /home/stk/brick/mb9200/buildroot/build_arm/staging_dir/bin
>  > -ccache/../lib/gcc/arm-linux-uclibc/4.1.1/../../../../arm-linux-uclibc/sys-inclu
>  > de/bits/uClibc_stdio.h:120,
>  >                  from /home/stk/brick/mb9200/buildroot/build_arm/staging_dir/bin
>  > -ccache/../lib/gcc/arm-linux-uclibc/4.1.1/../../../../arm-linux-uclibc/sys-inclu
>  > de/stdio.h:73,
>  >                  from ../../../../xenomai-2.4.3/src/skins/posix/init.c:20:
>  > ../../../src/include/asm/xenomai/syscall.h: In function 'xeno_arm_features_check
>  > ':
>  > ../../../src/include/asm/xenomai/syscall.h:295: error: 'stderr' undeclared (firs
>  > t use in this function)
>  > ../../../src/include/asm/xenomai/syscall.h:295: error: (Each undeclared identifi
>  > er is reported only once
>  > ../../../src/include/asm/xenomai/syscall.h:295: error: for each function it appe
>  > ars in.)
>  > 
>  > Obviously there is something wrong with the include path used:
>  > uClibc_mutex.h should not include 'pthread.h' in the Xenomai
>  > distribution but rather the version in uClibc itself.
>  > 
>  > Why this happens I'm trying to discover.
>  > 
>  > The complete configure I'm using is:
>  > 
>  > ../xenomai-2.4.3/configure --build=i686-pc-linux-gnu --host=arm-linux-uclibc --enable-arm-mach=at91sam926x --enable-arm-tsc
>  > 
>  > Thanks in advance.
> 
> Well, I understand that it may not be important to you if you do not
> intend to use the posix skin, but we should try and solve this issue
> (which seems to be a uclibc issue). Including posix skin pthread.h
> instead of libc pthread.h should be no problem, since posix skin
> pthread.h include the libc pthread.h. The problem here is due to the
> fact that asm-arm/syscall.h is trying to use stderr whereas we are at
> the very beginning of stdio.h where stderr is not defined yet.
> 
> I have to admit that I have no idea here other than defining a function
> in init.c which calls fprintf and to call this function instead of
> fprintf in asm-arm/syscall.h
> 
> Philippe, any better idea ?
> 

No, but I do have an almost as ugly one to suggest:

--- include/asm-arm/syscall.h	(revision 3729)
+++ include/asm-arm/syscall.h	(working copy)
@@ -222,7 +222,6 @@
 #define XENOMAI_SYSARCH_TSCINFO                 4

 #ifndef __KERNEL__
-#include <stdio.h>
 #include <stdlib.h>
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -230,6 +229,8 @@
 #include <fcntl.h>
 #include <unistd.h>
 #include <limits.h>
+#include <error.h>
+#include <errno.h>

 __attribute__((weak)) struct __xn_tscinfo __xn_tscinfo = {
 	type: -1
@@ -291,17 +292,15 @@
 	err = XENOMAI_SYSCALL2(__xn_sys_arch,
 			       XENOMAI_SYSARCH_TSCINFO, &__xn_tscinfo);
 	if (err) {
-	  error:
-		fprintf(stderr, "Xenomai: Your board/configuration does not"
-			" allow tsc emulation in user-space: %d\n", err);
-		exit(EXIT_FAILURE);
+	  fail:
+		error(EXIT_FAILURE, err,
+		      "Xenomai: Your board/configuration does not"
+		      " allow tsc emulation in user-space\n");
 	}

 	fd = open("/dev/mem", O_RDONLY | O_SYNC);
-	if (fd == -1) {
-		perror("Xenomai init: open(/dev/mem)");
-		exit(EXIT_FAILURE);
-	}
+	if (fd == -1)
+		error(EXIT_FAILURE, errno, "Xenomai init: open(/dev/mem)");

 	page_size = sysconf(_SC_PAGESIZE);

@@ -313,10 +312,8 @@
 		phys_addr = (unsigned long) __xn_tscinfo.u.fr.counter;
 		addr = mmap(NULL, page_size, PROT_READ, MAP_SHARED,
 			    fd, phys_addr & ~(page_size - 1));
-		if (addr == MAP_FAILED) {
-			perror("Xenomai init: mmap(/dev/mem)");
-			exit(EXIT_FAILURE);
-		}
+		if (addr == MAP_FAILED)
+			error(EXIT_FAILURE, errno, "Xenomai init: mmap(/dev/mem)");

 		__xn_tscinfo.u.fr.counter =
 			((volatile unsigned *)
@@ -330,10 +327,8 @@
 		phys_addr = (unsigned long) __xn_tscinfo.u.dec.counter;
 		addr = mmap(NULL, page_size, PROT_READ, MAP_SHARED,
 			    fd, phys_addr & ~(page_size - 1));
-		if (addr == MAP_FAILED) {
-			perror("Xenomai init: mmap(/dev/mem)");
-			exit(EXIT_FAILURE);
-		}
+		if (addr == MAP_FAILED)
+			error(EXIT_FAILURE, "Xenomai init: mmap(/dev/mem)");

 		__xn_tscinfo.u.dec.counter =
 			((volatile unsigned *)
@@ -342,18 +337,15 @@
 	}
 #endif /* CONFIG_XENO_ARM_HW_DIRECT_TSC == __XN_TSC_TYPE_DECREMENTER */
 	case __XN_TSC_TYPE_NONE:
-		goto error;
+		goto fail;
 		
 	default:
-		fprintf(stderr,
-			"Xenomai: kernel/user tsc emulation mismatch.\n");
-		exit(EXIT_FAILURE);
+		error(EXIT_FAILURE, err,
+		      "Xenomai: kernel/user tsc emulation mismatch.\n");
 	}

-	if (close(fd)) {
-		perror("Xenomai init: close(/dev/mem)");
-		exit(EXIT_FAILURE);
-	}
+	if (close(fd))
+		error(EXIT_FAILURE, errno, "Xenomai init: close(/dev/mem)");
 #endif /* CONFIG_XENO_ARM_HW_DIRECT_TSC */
 }
 #define xeno_arch_features_check() xeno_arm_features_check()

-- 
Philippe.