segfault?

haarts · Post by **haarts** » Sun Apr 01, 2007 2:34 pm

Hi all,

My problem is twofold, I am terrible with c so the Java implementation was very welcome. However when running the example from the SDK package:

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 java -jar samples.jar

I get the following output:

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Sample Application for the Iowkit-library
Checking Library Version...The IowKit plattform-library was not found!

Digging into the source code I noticed that this message comes from the a failed IowKit.version() call. So a made a very simple c program to verify the success of the version() call in c;

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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include "iowkit.h"

int main(int argc, char* argv[]) {
        printf('%s\n', IowKitVersion());
        return 0;
}

And although this program compiles it segfaults when I try to run it. Am I missing something blatantly obvious? I noticed in the documentation that it should return "IO-Warrior Kit V1.4" but I installed the latest 1.5. Does it have to do with that?

I am running all this on a ARM processor with SableVM and gcc (GCC) 4.1.2 20061115 (prerelease) (Debian 4.1.1-21). The iowkit lib is located in /usr/lib.

Thanks for any suggestions!

Harm

Robert Marquardt · Post by **Robert Marquardt** » Sun Apr 01, 2007 3:32 pm

Which kernel version is that? 32 bit or 64 bit?
Did you successfully install driver and iowkit?

IowKitVersion() should report 1.5. The documentation is obviously in error.

We have only tested on x86 architecture so there may still be bugs.

haarts · Post by **haarts** » Sun Apr 01, 2007 3:52 pm

It is an ARM processor. And I have no idea whether it is 32 or 64 bit but I am willing to bet it is 32. From /proc/cpuinfo:

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Processor       : XScale-IXP42x Family rev 1 (v5l)
BogoMIPS        : 266.24
Features        : swp half fastmult edsp 
CPU implementer : 0x69
CPU architecture: 5TE
CPU variant     : 0x0
CPU part        : 0x41f
CPU revision    : 1
Cache type      : undefined 5
Cache clean     : undefined 5
Cache lockdown  : undefined 5
Cache format    : Harvard
I size          : 32768
I assoc         : 32
I line length   : 32
I sets          : 32
D size          : 32768
D assoc         : 32
D line length   : 32
D sets          : 32

Hardware        : Linksys NSLU2
Revision        : 0000
Serial          : 0000000000000000

The library installed OK so I strongly suspect that the IowKitVersion method is not functioning properly(on my ARM processor(?)). I unzipped the samples.jar, modified the IoBlink.java to skip the version() method. Then recompiled and ran it(with -Djava.library.path=/usr/lib). This time I got some nice blinking lights on my IOW24. Awesome! So I'll steer clear of the version method as of now.

Thanks for the fast response!

haarts · Post by **haarts** » Sun Apr 01, 2007 4:06 pm

Hmmm, I might be mistaken. I just retried the version() method in my Java class and it works fine now. I added -Djava.library.path=/usr/lib to the invocation. Still don't know what went wrong with the C implementation. <shrugs>

towaibw · Post by **towaibw** » Sun Apr 01, 2007 5:19 pm

Which firmware exactly do you use for the NSLU2?

Robert Marquardt · Post by **Robert Marquardt** » Sun Apr 01, 2007 5:41 pm

I wanted to know the kernel version. The XScale should not be 64 bit.
IowKitVersion is the only function i expect no problems at all with. It simply returns a static text.

Maybe replace the files jni.h and jni_md.h by the version from your Java installation on that machine and recompile/reinstall libiowkit.so. I have added the files because for Windows they are not easy to get and i hate it to get complaints about missing files.

wayoda · Post by **wayoda** » Sun Apr 01, 2007 6:35 pm

Hello haarts,

haarts wrote:Hmmm, I might be mistaken. I just retried the version() method in my Java class and it works fine now. I added -Djava.library.path=/usr/lib to the invocation. Still don't know what went wrong with the C implementation. <shrugs>

A nifty little "C"-error (happened to me many times...)

You put single-quotes around around the '%s\n' part in the printf statement.

With double quotes

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//compile with gcc -liowkit -o little_test little_test.c
printf("%s\n",IowKitVersion());

it works. :-)

Eberhard

Robert Marquardt · Post by **Robert Marquardt** » Mon Apr 02, 2007 5:41 am

Argh, did not see it either. Too much Pascal.

haarts · Post by **haarts** » Mon Apr 02, 2007 9:34 am

Aha! My C n00bness strikes again. Thanks a lot. If still of interest here is my kernel version:

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Linux slug 2.6.18-4-ixp4xx #1 Thu Feb 22 14:00:55 UTC 2007 armv5tel GNU/Linux

I am running Debian testing.