This option enables various optimizations for running under the KVM hypervisor. Overhead for the kernel when not running inside KVM should be minimal. In case of doubt, say Y
Enables ePAPR para-virtualization support for guests. In case of doubt, say Y
Support for running natively on the hardware, i.e. without a hypervisor. This option is not user-selectable but should be selected by all platforms that need it.
Support from booting from Open Firmware or yaboot using an Open Firmware client interface. This enables the kernel to communicate with open firmware to retrieve system information such as the device tree. In case of doubt, say Y
This enables code to use a new device tree binding for describing CPU compatibility and features. Saying Y here will attempt to use the new binding if the firmware provides it. Currently only the skiboot firmware provides this binding. If you're not sure say Y.
Select this option if your platform supports SMP and your interrupt controller provides less than 4 interrupts to each cpu. This will enable the generic code to multiplex the 4 messages on to one ipi.
The MPIC global timer is a hardware timer inside the Freescale PIC complying with OpenPIC standard. When the specified interval times out, the hardware timer generates an interrupt. The driver currently is only tested on fsl chip, but it can potentially support other global timers complying with the OpenPIC standard.
The driver provides a way to wake up the system by MPIC timer. e.g. "echo 5 > /sys/devices/system/mpic/timer_wakeup"
Enables support for the MPIC message registers. These registers are used for inter-processor communication.
This option enables a MPIC driver workaround for some chips that have a bug that causes some interrupt source information to not read back properly. It is safe to use on other chips as well, but enabling it uses about 8KB of memory to keep copies of the register contents in software.
G3 and G4 processors have an on-chip temperature sensor called the 'Thermal Assist Unit (TAU)', which, in theory, can measure the on-die temperature within 2-4 degrees Celsius. This option shows the current on-die temperature in /proc/cpuinfo if the cpu supports it. Unfortunately, this sensor is very inaccurate when uncalibrated, so don't assume the cpu temp is actually what /proc/cpuinfo says it is.
The TAU supports an interrupt driven mode which causes an interrupt whenever the temperature goes out of range. This is the fastest way to get notified the temp has exceeded a range. With this option off, a timer is used to re-check the temperature periodically. If in doubt, say N here.
The TAU hardware can compare the temperature to an upper and lower bound. The default behavior is to show both the upper and lower bound in /proc/cpuinfo. If the range is large, the temperature is either changing a lot, or the TAU hardware is broken (likely on some G4's). If the range is small (around 4 degrees), the temperature is relatively stable. If you say Y here, a single temperature value, halfway between the upper and lower bounds, will be reported in /proc/cpuinfo. If in doubt, say N here.
Say Y here if you're going to use hardware that connects to the QE GPIOs.
The CPM2 (Communications Processor Module) is a coprocessor on embedded CPUs made by Freescale. Selecting this option means that you wish to build a kernel for a machine with a CPM2 coprocessor on it (826x, 827x, 8560).
Supports for the ULI1575 PCIe south bridge that exists on some Freescale reference boards. The boards all use the ULI in pretty much the same way.
Uses information from the OF or flattened device tree to instantiate platform devices for direct mapped RTC chips like the DS1742 or DS1743.
This option provides backwards compatibility with the old gen_rtc.ko module that was traditionally used for old PowerPC machines. Platforms should migrate to enabling the RTC_DRV_GENERIC by hand replacing their get_rtc_time/set_rtc_time callbacks with a proper RTC device driver.
Say Y here to enable soft power-off functionality on the Freescale boards with the MPC8349E-mITX-compatible MCU chips. This driver will also register MCU GPIOs with the generic GPIO API, so you'll able to use MCU pins as GPIOs.