[En-Nut-Discussion] ARM Optimization Issue?

[Bob Wirka]

Our platform is an AT91SAM7X512 with a LAN8720 PHY connected with RMII.

We hammer the board with network traffic (all UDP & broadcasts) for testing.

With release versions of the NutOS libraries, the code crashes (_excpt_dummy).

With debug versions of the NutOS libraries, it doesn't crash.

With either release or debug, the code will start up and operate. However, when we "stress" it a little, it crashes.

The product supports BACnet. We can scan the I/O repeatedly without issue. If we start pinging the unit while scanning, however, we get a crash.

Would anyone have an opinion on what might be the issue? I'm thinking there's something about optimization. Have tried -O1 instead of -Os for the libraries, but get the same results. Seems that only -O0 will work.

Thanks,

Bob Wirka
Realtime Control Works.