OMAP-L138: Shared memory between DSP running bare metal application and ARM running linux

Aviv Prital

Prodigy 140 points

Part Number: OMAP-L138

Hi,

My custom board is based on OMAPL-138.

I need to use the shared memory between DSP running bare metal application and ARM running linux.

What is the way to reserve the same fixed address in shared memory for usage of both cores?

For DSP I suppose I may use section in linker command file with corresponding pragma in the code, what is the way to do this in linux?

Thanks,

Aviv

over 5 years ago

0 Rex Chang over 5 years ago

TI__Guru 50170 points

Hi, Aviv,

Is the issue the same as this one, but different board? If it is, the linux configuration should be the same.

https://e2e.ti.com/support/processors/f/791/t/830904

There is another thread using OMAP-L138 shared memory, hope this thread may be some guidance to your baremetal app.

https://e2e.ti.com/support/processors/f/791/p/820079/3036070

Rex

0 Aviv Prital over 5 years ago in reply to Rex Chang

Prodigy 140 points

Hi Rex,

the question relates to https://e2e.ti.com/support/processors/f/791/t/830904 further step.

Sharing the memory works well for me, but I choose the memory location arbitrary.

The question is: how can I make sure that the memory chunk I choose will not be used by some other SW at both DSP and ARM cores? Is there a way to reserve this memory chunk for my exclusive usage?

Thanks,

Aviv

0 Rex Chang over 5 years ago in reply to Aviv Prital

TI__Guru 50170 points

Hi, Aviv,

I see. The memory is under reserved-memory region. So, regular ARM linux malloc will not touch that area. However, using mmap is different story which shouldn't happen. On the DSP side, DSP knows the memory usage, and that shouldn't happen either.

Rex

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OMAP-L138: Shared memory between DSP running bare metal application and ARM running linux