FreeRTOS config value for STM32F207

vicui wrote on Tuesday, May 15, 2012:

I am working on STM32F207 CORTEX M3, I ported FreeRTOS v7.1.1 and  LWIP1.4.0 to setup web server. And found that speed is lower if sending More web pages. At common, I write a simple sending application to test sending speed, it is up to 8Mb/s, so I think it is not network problem.
But the application only setup connection one times, in my web server, it will close connection after send one page out. So it needs setup connection And close connection more times. I don’t know if it causes performance down.I also consider the default SYSCALL priority value is not best one for Cortex M3. Anyone has recommend value for those definition ?

> /* This is the raw value as per the Cortex-M3 NVIC.  Values can be 255
> (lowest) to 0 (1?) (highest). */
> #define configKERNEL_INTERRUPT_PRIORITY         255
> #define configMAX_SYSCALL_INTERRUPT_PRIORITY   191 /* equivalent to
> 0xb0, or priority 11. */
> /* This is the value being used as per the ST library which permits 16
> priority values, 0 to 15.  This must correspond to the
> configKERNEL_INTERRUPT_PRIORITY setting.  Here 15 corresponds to the
> lowest
> NVIC value of 255. */

rtel wrote on Tuesday, May 15, 2012:

The configMAX_SYSCALL_INTERRUPT_PRIORITY can be set to any value that is valid for the Cortex-M3 device you are using.  I would not however consider that to be connected with any problem you may be having.

It is not clear what the problem is though.  You have written a small application that can send at 8Mb/s - was this with or without FreeRTOS?

Does the web server run faster without FreeRTOS?  If so, it might be worth looking at the recent history in the lwIP mailing list, as there was a discussion about just that very recently, although I’m not sure what the conclusion was.

If your web server is opening and closing lots of connections, then I suspect the main cause of the problem will be the lwIP configuration.  If you look at the gathered lwIP stats, or turn on its debug features, you will be able to see if it is running out of any particular resource or having to drop packets.  Maybe that would help you tune up the performance?


vicui wrote on Tuesday, May 15, 2012:

hi richard:

my small application get 8Mb/s with freeRTOS.
I haven’t test webpage without FreeRTOS.  it is difficult to get clear LWIP configure, but I will have a try

eadboston wrote on Sunday, March 24, 2013:


     I am looking for a stm32f207 port of free RTOS…. Do you have one or know where I can download one?