ssn1971 wrote on Saturday, December 11, 2010:

Hello All.
I need use MPU on MC9S12XET256 processor.
Standart port to HCS12X don’t include function for run with MPU module.
I don’t know as this do ( i.e. add MPU support to HCS12X port ).
Help me, please.

rtel wrote on Saturday, December 11, 2010:

I have not looked at the MPU on that particular part, but generally adding MPU support is not a trivial task.  You can compare the Cortex M3 port to the Cortex M3 MPU port to get an idea.

Presumably if there is an MPU then you also have some sort of privileged and non-privileged modes that the CPU runs in?  Getting the kernel to use those correctly would be the first task.

I would consider whether you need full MPU support where each task switched memory regions as part of the task context, or if you just need basic support whereby the MPU could be statically configured at initialisation time and then just not touched from that point on.

If you have the resource to make this a contract job, then feel free to contact me directly using the ‘contact’ page of the site, otherwise it is highly unlikely that MPU support for this device will be made official in the near future (there is a very heavy development work load already scheduled and planned).