Hi,
I've got a 64bit Debian (Lenny) system but unfortunately I have a 
requirement where I need to run a PHP extension on this system that was 
  compiled on a 32bit system. The source isn't available and the people 
who produce the extension won't recompile it.
$ uname -a
Linux D2-100-70251 2.6.27.10-grsec #1 SMP Wed May 20 23:47:45 BST 2009 
x86_64 GNU/Linux
$ sudo tail /var/log/apache/error.log
PHP Warning:  PHP Startup: Unable to load dynamic library 
'/usr/lib/php5/20060613/php520_cybersource.so' - 
/usr/lib/php5/20060613/php520_cybersource.so: wrong ELF class: 
ELFCLASS32 in Unknown on line 0
$ file /usr/lib/php5/20060613/php520_cybersource.so
/usr/lib/php5/20060613/php520_cybersource.so: ELF 32-bit LSB shared 
object, Intel 80386, version 1 (SYSV), dynamically linked, not stripped
This PHP extension also comes with it's own libs that I've added to 
ld.so.conf.
Now I'm guessing the problem is because the PHP extension was compiled 
on a 32bit system and I'm trying to run it on a 64 bit system and it's 
nothing to do with my hand rolled kernel and me missing out some kind of 
backward compatibility option?
I'm also guessing I'm a bit stuck and there's no work around for this? I 
can reinstall with a 32bit OS as this system is in testing but of 
course, ideally I'd like to run a 64bit OS on the 64bit processor that's 
inside the box.
Thanks,
David.
-- 
  .''`.     David Ramsden
: :'  :    http://0wned.it/
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   `-  Debian - Because it works (tm).