Can I set the heap size to zero?

[Lars Beiderbecke]

In my STM32F72xx/3xx project, I'm not allocating memory dynamically, i.e., I'm using neither malloc nor free. And I'm restricting myself to C, with no C++ parts.

Is there a reason I shouldn't set the heap size to zero? Do any of the drivers, HAL or CMSIS, or FatFs, rely on the heap?

[Piranha]

Yes, You can and should do it. That is the only way how I make my projects and my projects do work. As far as I know (but can not guarantee) HAL doesn't use heap, though I do not use HAL anymore. Can't comment on FatFs.

What exactly do You mean by CMSIS? It has many different parts!

[Tesla DeLorean]

FatFs, depends on the configuration, LFN support can use malloc/free.

Some of ST's USB code uses malloc/free

[Pavel A.]

To be sure, fill the heap with some pattern before running your stuff, later check if it has (not) changed.

-- pa