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Add option to use CCMRAM on F303xE. #11756
Add option to place data to ccm ram on STM32F303xE. Similar functionality exists already for at least STM32F437xG target.
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General thought, which you don't need to address here. Any platform which does have CCM RAM probably should use it for at least the boot/interrupt stack, and maybe the main thread stack.
Those are a lot of your scratch space which you'd want to be fast, and you probably get away with avoiding any bus mastering issues that stop you viewing it as general-purpose static/heap RAM - you won't be generally trying to DMA into the stack.
And gives you a RAM saving without any explicit application area attribute additions.
Discussed with @JammuKekkonen - this is fine as-is, but the F303 doesn't have Ethernet, and there's no DMA in the HAL, so we can see no reason not to treat the CCMRAM as general-purpose RAM for Mbed OS. So a later extension might be to pop a
The F437 does have Ethernet, but some boards don't. Maybe the F437 scatter file could do the same based on a