target/ppc: Wire up BookE ATB registers for e500 family

From the Freescale PowerPC Architecture Primer:

  Alternate time base APU. This APU, implemented on the e500v2, defines
  a 64-bit time base counter that differs from the PowerPC defined time
  base in that it is not writable and counts at a different, and
  typically much higher, frequency. The alternate time base always
  counts up, wrapping when the 64-bit count overflows.

This implementation of ATB uses the same frequency as the TB. The
existing spr_read_atbu/l functions are unused without this patch
to wire them into the SPR.

RTEMS uses this SPR on the e6500, though this hasn't been tested.

Message-ID: <20241219034035.1826173-6-npiggin@gmail.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

0 files changed, 0 insertions, 0 deletions