ARM-software/CMSIS_5

Issues with new ARMv8 MPU attributes

kjbracey opened this issue · 1 comments

kjbracey commented

I just noticed the new MPU_ATTR_NORMAL_OUTER_NON_CACHEABLE etc defines.

A few issues with these, in descending order of importance:

  • The TR transient indication is inverted. Bit 3 needs to be set for transient.
  • The 0b binary prefix requires a very recent language standard or a compiler extension.
  • Shouldn't they have an ARM_ prefix to match surrounding defines?
  • But is the OUTER_ and INNER_ necessary?

And as an aside, just for anyone happening to search and end up here - it's not specified anywhere what the "transient" flags of the default memory map are. Apparently the default regions are transient in the M55, which surprised me.

JonatanAntoni commented

Would you mind raising a PR with your proposed changes?
Perhaps switch over to ARM-software/CMSIS_6 and we leave it unchanged here. Adding ARM_ prefix might be a good idea but would break backward compatibility.