unix - Synthetic target CPU

[Steven Johnson]

Hi,

Ive currently got an application running on PowerPC with a customised 
BSP, with RTEMS.  It works great, and has for years. Its currently using 
RTEMS 4.6.2.  We dont use the Posix API in RTEMS, but the native RTEMS 
calls for threads, semaphores, etc.

Now, ive got to make a native Linux version of this application.

The choices are:
1. Change all of the calls to Semaphore/thread calls compatible with 
Linux, and conditionally build my program. (big job).
2. Use this "unix - Synthetic target CPU".

Is this "unix - Synthetic target CPU" suitable for this?  Is it robust 
enough for a production application?  Does it introduce much overhead?  
Is it just a wrapper to the native threading/semaphore calls of the OS?

I still need this program to work on my embedded system, and I wont use 
the Posix api on RTEMS, cause i need RTEMS to be as small as possible.

Any information (or pointers to information) anyone can give on the 
"unix - Synthetic target CPU" would be appreciated.

Steven