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About FreeRTOS+SDRAM+LwIP and heap

Posted by adissida on October 31, 2015


LwIP works grate besides that I have problem to load bigger html in size. I run the latest FreeRTOS 8.2.2. Using Atmel UC3 with external 32MB SDRAM. I have defined the heap size of 32MB for RTOS and works grate. But how will RTOS use so mutch RAM? Im wounder becaus how will LwIP use the external RAM, is it trough RTOS? The problem with loading bigger pages must have to do with this, the buffers arent big enough. I havent seen anywhere where I can define LwIP to use external RAM.

Any ideas?

About FreeRTOS+SDRAM+LwIP and heap

Posted by rtel on October 31, 2015

There is some information on how FreeRTOS uses its heap here: http://www.freertos.org/a00111.html

lwIP can use statically allocated buffers, or dynamically allocated buffers, but if you have specific lwIP questions, please ask them on the lwIP mailing list, rather than here.

If you use heap_3, which uses the standard malloc and free, then you need to ensure all other uses of malloc and free are made thread safe.

If you use anything other than heap_3 then you can re-direct malloc and free to pvPortMalloc and vPortFree.

Note we also have our own TCP/IP stack: http://www.freertos.org/tcp

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