From: Jason Thorpe <thorpej@nas.nasa.gov>
   Date: Mon, 25 Nov 1996 08:56:44 -0800

   On Mon, 25 Nov 1996 11:14:09 -0500 
    Ian Lance Taylor <ian@cygnus.com> wrote:

    > As far as I can see, it is not necessary to check the dynamic
    > interpreter in the kernel.  Instead, the dynamic interpreter for a
    > particular OS emulation can use a different library search path, and
    > use a library which is correct for the system being emulated.  If
    > necessary, a special kernel call can be used to set the emulation mode
    > of the process.

   Yah, this is how Linux does it... However, that assumes that the 
   special call's syscall number will be what the special call expects,
   which may not always be the case.

When using this approach, I don't think that binary compatibility of
the dynamic interpreter is achievable.  You can only obtain source
compatibility at best.  Fortunately, there aren't very many dynamic
interpreters.

Ian