29 lines
1,021 B
Plaintext
29 lines
1,021 B
Plaintext
|
@node Platform, Contributors, Maintenance, Top
|
||
|
|
@c %MENU% Describe all platform-specific facilities provided
|
||
|
|
@appendix Platform-specific facilities
|
||
|
|
|
||
|
|
@Theglibc{} can provide machine-specific functionality.
|
||
|
|
|
||
|
|
@menu
|
||
|
|
* PowerPC:: Facilities Specific to the PowerPC Architecture
|
||
|
|
@end menu
|
||
|
|
|
||
|
|
@node PowerPC
|
||
|
|
@appendixsec PowerPC-specific Facilities
|
||
|
|
|
||
|
|
Facilities specific to PowerPC that are not specific to a particular
|
||
|
|
operating system are declared in @file{sys/platform/ppc.h}.
|
||
|
|
|
||
|
|
@deftypefun {uint64_t} __ppc_get_timebase (void)
|
||
|
|
Read the current value of the Time Base Register.
|
||
|
|
|
||
|
|
The @dfn{Time Base Register} is a 64-bit register that stores a monotonically
|
||
|
|
incremented value updated at a system-dependent frequency that may be
|
||
|
|
different from the processor frequency. More information is available in
|
||
|
|
@cite{Power ISA 2.06b - Book II - Section 5.2}.
|
||
|
|
|
||
|
|
@code{__ppc_get_timebase} uses the processor's time base facility directly
|
||
|
|
without requiring assistance from the operating system, so it is very
|
||
|
|
efficient.
|
||
|
|
@end deftypefun
|