On 07/06/2021 17:22, Tim wrote:
This is probably not really a NuttX question per se, but it relates to
getting the MCAN interface for a sama5d2 to work properly. And you are all
such knowledgable and helpful people :)
The MCAN controllers assume the base address of the message ram is at
0x200000+offsets. 0x200000 is the internal SRAM whereas everything else is
in DDR from 0x2000000. I will readily confess that this side of
programming
is my very weakest!!
I will, I believe, need to declare - place - MCAN related structures such
that they (or at least some elements of them) are in SRAM.
Is that possible? "CONFIG_MM_REGIONS" related maybe?
What does the internal SRAM get used for as the system.map file lists
nothing there at all.
Or have I got it wrong and this isn't the way to sort it - perhaps the
processor DMA "matrix" stuff (hope not - don't understand the datasheet
section on this at all!)?
Thanks!
Tim.
That's some excellent guidance, thanks Nathan - lots of reading/learning
needed! I have started playing with the .ld file but haven't seen the
message buffer address change as yet; need to learn more about the
syntax and/or making sure the build picks up the changes to the board's
.ld file.
Then I can worry about things overlapping.
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