configTOTAL_HEAP_SIZE max size

Hi,

I'm using the AM243x-EVM.

I'm using FreeRTOS.

In FreeRTOSConfig.h   I set  configTOTAL_HEAP_SIZE = 20 * 1024 1024;  /*20M*/

In the linker.cmd I have  --heap_size = 30 * 1024 * 1024   /*30M*/

Then in main() I call xPortGetFreeHeapSize(); and the value returns ~ (4 * 1024 * 1024) /*4M*/

How can I raise it up to 20M ?

Thanks,

Eli