LAUNCHXL2-RM57L: LAUNCHXL2 RM57L FreeRTOS and LWIP

Michael Nicholas

Part Number: LAUNCHXL2-RM57L
Other Parts Discussed in Thread: HALCOGEN

I've seen several questions posted on this same topic, some dating back many years. Has anyone gotten FreeRTOS + LWIP to work?

The LWIP example for Hercules is not very good. It includes all of the C files into another C file. It is not hooked into the code properly with timers, instead using while() loops for timing.

On top of that, attempting to use it with FreeRTOS has a problem with the Memory Protection Unit. The example code cannot get an IP address from DHCP, but digging down into the code, it is faulting on a register access that is related to MPU-PMU settings. I just don't know how to fix it, either through HalCoGen or manually overriding memory settings.

over 1 year ago

0 jagadish gundavarapu over 1 year ago

TI__Guru 62590 points

Hi Michael.

Let me discuss with my senior colleague once for this demo and i will try to provide you an update ASAP.

--
Thanks & regards,
Jagadish.

0 Michael Nicholas over 1 year ago in reply to jagadish gundavarapu

Prodigy 20 points

I was able make a connection (DHCP gave an IP address) after disabling the Cache. I'm sure there is a way to set up a reserved section of memory for ethernet buffers and configuring MPU settings for "write-through", but I don't need the Cache anyway, so I just disabled it.
I'm still working on porting the httpd web server application into FreeRTOS, but that is pretty straight-forward.

0 Michael Nicholas over 1 year ago in reply to Michael Nicholas

Prodigy 20 points

Unfortunately, just disabling Cache was not enough. That fixed transmit and was able to get an IP address if done prior to starting the FreeRTOS task scheduler, but after starting tasking, it crashes (jumps to prefetchdata abort loop) after trying to free the Received dma buffer. It seems like the memory protection unit is still a problem.
I think we're going to give up on FreeRTOS + LWIP. The Hercules port of FreeRTOS isn't stable anyway. The scheduler doesn't work right in preemptive mode, and it hogs the RTI timer so I can't use one of the other RTI timers. Again, it "protects" it so I can't write to the register without the system crashing. And, if I set up the timer prior to starting tasking, FreeRTOS kills my timer.