Experimental Physics and
Industrial Control System

Andrew Johnson <[email protected]> · Thu, 5 Apr 2012 11:27:24 -0600

Hi,

On 2012-04-05 王林 wrote:
> When I ask questions the year before last, I mentioned we wanted to chose
>  CPCI-6200 (Dual core MPC8572, PCIe) for our cPCI VxWorks/EPICS system.
>  Actually, for the sake of reducing the difficuly, we chose CPCI-6020
>  (MPC7410, PCI) at that time. But these days, we want to purchase this
>  CPCI-6200 for our alternative choice of cPCI CPU board, and try to run
>  EPICS on vxWorks 6.6 or 6.8, AMP or SMP. But I am not sure whether it is
>  possible to run EPICS on dual core 85XX CPU, and whether there are other
>  important issues that I should think about. Any advice?

It might be possible to run current versions of EPICS on that CPU if it can 
support a UP build of vxWorks, but they would not make use of the second core.  
The current vxWorks support routines for EPICS Base were written long before 
Wind River decided to support SMP, and thus they make many assumptions which 
are incorrect on an SMP system.  For example they assume that within an 
intLock() ... intUnlock() pair no other EPICS code can be running, which is 
true on a UP system but not on SMP.

If you have the time to write a new vxWorks-SMP support layer for EPICS then I 
would be happy to work with you to get your new code accepted into a future 
version of the EPICS distribution, but it would probably take you several 
months of C development work to create and test the new support code.  I 
believe there are other EPICS sites that are also interested in SMP support, 
but nobody has offered to work on this yet.

I don't know how the AMP mode works; if it allows you to run programs written 
for the original UP vxWorks API then you should be able to run an IOC on the 
board in this mode.  You might even be able to run two separate IOCs on the 
two cores if the AMP mode makes the board look like two completely independent 
computers, but you would have to be very careful with the device drivers you 
load so that you don't have the two machines trying to control the same piece 
of hardware at the same time.

- Andrew
-- 
Never interrupt your enemy when he is making a mistake.
-- Napoleon Bonaparte

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System