This option selects whether a 32-bit or a 64-bit kernel will be built.
There are five families of 32 bit PowerPC chips supported. The most common ones are the desktop and server CPUs (601, 603, 604, 740, 750, 74xx) CPUs from Freescale and IBM, with their embedded 512x/52xx/82xx/83xx/86xx counterparts. The other embeeded parts, namely 4xx, 8xx, e200 (55xx) and e500 (85xx) each form a family of their own that is not compatible with the others. If unsure, select 52xx/6xx/7xx/74xx/82xx/83xx/86xx.
There are two families of 64 bit PowerPC chips supported. The most common ones are the desktop and server CPUs (POWER3, RS64, POWER4, POWER5, POWER5+, POWER6, ...) The other are the "embedded" processors compliant with the "Book 3E" variant of the architecture
Cause the compiler to optimize for POWER4/POWER5/PPC970 processors. The resulting binary will not work on POWER3 or RS64 processors when compiled with binutils 2.15 or later.
Cause the compiler to optimize for the PPE of the Cell Broadband Engine. This will make the code run considerably faster on Cell but somewhat slower on other machines. This option only changes the scheduling of instructions, not the selection of instructions itself, so the resulting kernel will keep running on all other machines. When building a kernel that is supposed to run only on Cell, you should also select the POWER4_ONLY option.
This is the Performance Monitor support found on the e500 core and some e300 cores (c3 and c4). Select this only if your core supports the Embedded Performance Monitor APU
This option enables kernel support for larger than 32-bit physical addresses. This feature may not be available on all cores. If you have more than 3.5GB of RAM or so, you also need to enable SWIOTLB under Kernel Options for this to work. The actual number is platform-dependent. If in doubt, say N here.
This option enables kernel support for the Altivec extensions to the PowerPC processor. The kernel currently supports saving and restoring altivec registers, and turning on the 'altivec enable' bit so user processes can execute altivec instructions. This option is only usefully if you have a processor that supports altivec (G4, otherwise known as 74xx series), but does not have any affect on a non-altivec cpu (it does, however add code to the kernel). If in doubt, say Y here.
This option enables kernel support for the Vector Scaler extensions to the PowerPC processor. The kernel currently supports saving and restoring VSX registers, and turning on the 'VSX enable' bit so user processes can execute VSX instructions. This option is only useful if you have a processor that supports VSX (P7 and above), but does not have any affect on a non-VSX CPUs (it does, however add code to the kernel). If in doubt, say Y here.
This option enables kernel support for the Signal Processing Extensions (SPE) to the PowerPC processor. The kernel currently supports saving and restoring SPE registers, and turning on the 'spe enable' bit so user processes can execute SPE instructions. This option is only useful if you have a processor that supports SPE (e500, otherwise known as 85xx series), but does not have any effect on a non-spe cpu (it does, however add code to the kernel). If in doubt, say Y here.
Select this option to enable more accurate task and CPU time accounting. This is done by reading a CPU counter on each kernel entry and exit and on transitions within the kernel between system, softirq and hardirq state, so there is a small performance impact. This also enables accounting of stolen time on logically-partitioned systems running on IBM POWER5-based machines. If in doubt, say Y here.
This enables the powerpc-specific perf_event back-end.
This enables support for systems with more than one CPU. If you have
a system with only one CPU, say N. If you have a system with more
than one CPU, say Y. Note that the kernel does not currently
support SMP machines with 603/603e/603ev or PPC750 ("G3") processors
since they have inadequate hardware support for multiprocessor
operation.
If you say N here, the kernel will run on single and multiprocessor
machines, but will use only one CPU of a multiprocessor machine. If
you say Y here, the kernel will run on single-processor machines.
On a single-processor machine, the kernel will run faster if you say
N here.
If you don't know what to do here, say N.