Porting Advice for phycore_mpc5554

[John Wood]

All,

Unlike other powerpc families, the mpc5554 has 16 interrupt priority
levels.
Additionally, exceptions like the decrementer and timebase and the new
fixed interval are enabled outside of the interrupt controller.

I would like to distinguish between interrupt level 15 and when I have
external interrupts disabled effectively giving me a 17th interrupt
level.  How should I set my mask and level macros.

I am assuming the mask is 0x1FFFF and the level is 0x10000 is this the
correct approach.

As a commentary, I have modifed the powerpc.h file in the score
directory to include MPC55XX style exceptions and the 300 possible
interrupts on the MPC5554.  This file could get out of hand with the
definitions done as such, would it make more sense to include a file
based upon the processor type and have that file located in the
appropriate libcpu directory.


Thanks for any input,
John