The MPU related forums and related SW solutions are transitioning to the Microchip Forum interface (including Linux):
No user migration is planned so you'll have to re-create a profile to benefit from these new forums.
Note as well that the at91.com website and
these the MPU-related Atmel community forums will be put in read-only mode in a few months.
MPU stands for Microprocessors, chips with ARM Application cores of the type ARM9 or Cortex-A, SAM9 or SAMA5 families.