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Memory allocation?

Posted by tord lindner on February 25, 2009

I'm a bit confused about memory allocation, everything created through the API I expect be allocated within the heap, all variables which are within a tasks/functions are on the stack. That is, on the heap again. But, variables declared outside any function are they inside or outside the heap declared in FreeRTOSConfig.h? What about declarations in Main before starting the scheduler?

BR Tord

RE: Memory allocation?

Posted by Dave on February 25, 2009
The heap is used to allocate the stacks that are used by the tasks. Therefore stack variables used by the tasks end up in the heap area, really they are on the stack its just that the stack came from the heap.

In main() the compiler will just use the stack as normal. This will be the stack used by main() as specified in the linker script. The compiler knows nothing about FreeRTOS or how it manages memory it just uses the data section and stack as normal.

RE: Memory allocation?

Posted by tord lindner on February 25, 2009
So all variables defined outside a function/task goes on the normal stack and the rest in the heap.? normally, are these two "stacks" going form top/button and hopefully never meet in the middle?

BR Tord

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