title: Determine target ISA extensions of binary file in Linux (library or executable)
body: <p>We have an issue related to a Java application running under a (rather old) FC3 on an Advantech POS board with a Via C3 processor. The java application has several compiled shared libs that are accessed via JNI.</p>
  
  <p>Via C3 processor is supposed to be i686 compatible. Some time ago after installing Ubuntu 6.10 on a MiniItx board with the same processor, I found out that the previous statement is not 100% true. The Ubuntu kernel hanged on startup due to the lack of some specific and optional instructions of the i686 set in the C3 processor. These instructions missing in C3 implementation of i686 set are used by default by GCC compiler when using i686 optimizations. The solution, in this case, was to go with an i386 compiled version of Ubuntu distribution.</p>
  
  <p>The base problem with the Java application is that the FC3 distribution was installed on the HD by cloning from an image of the HD of another PC, this time an Intel P4. Afterwards, the distribution needed some hacking to have it running such as replacing some packages (such as the kernel one) with the i386 compiled version.</p>
  
  <p>The problem is that after working for a while the system completely hangs without a trace. I am afraid that some i686 code is left somewhere in the system and could be executed randomly at any time (for example after recovering from suspend mode or something like that).</p>
  
  <p>My question is: </p>
  
  <ul>
  <li>Is there any tool or way to find out at what specific architecture extensions a binary file (executable or library) requires? <code>file</code> does not give enough information.</li>
  </ul>