powerpc: Provide a suitable AT_PLATFORM value
The glibc folks want to use AT_PLATFORM to select between possible
alternative versions of shared libraries. This commit makes the kernel
supply an AT_PLATFORM string that indicates what class of processor
we are running on. Processors with the same set of user-level
instructions and roughly the same instruction scheduling characteristics
are given the same AT_PLATFORM value; for example, 821, 823 and 860
are all reported as "ppc823", and 7447, 7447A, 7448, 7450, 7451, 7455
are all called "ppc7450".
The intention is that the AT_PLATFORM values match the values that
gcc accepts for the -mcpu= option. For values which are numeric
(e.g. -mcpu=750), "ppc" has been prepended.
This also adds a PPC_FEATURE_BOOKE bit to the AT_HWCAP value and sets
it for the 440 family and the Freescale 85xx family.
Signed-off-by: Paul Mackerras <paulus@samba.org>
3 files changed