+/*
+ * These are the support HW selectors for sysctlbyname. Parameters that are byte counts or frequencies are 64 bit numbers.
+ * All other parameters are 32 bit numbers.
+ *
+ * hw.memsize - The number of bytes of physical memory in the system.
+ *
+ * hw.ncpu - The maximum number of processors that could be available this boot.
+ * Use this value for sizing of static per processor arrays; i.e. processor load statistics.
+ *
+ * hw.activecpu - The number of processors currently available for executing threads.
+ * Use this number to determine the number threads to create in SMP aware applications.
+ * This number can change when power management modes are changed.
+ *
+ * hw.physicalcpu - The number of physical processors available in the current power management mode.
+ * hw.physicalcpu_max - The maximum number of physical processors that could be available this boot
+ *
+ * hw.logicalcpu - The number of logical processors available in the current power management mode.
+ * hw.logicalcpu_max - The maximum number of logical processors that could be available this boot
+ *
+ * hw.tbfrequency - This gives the time base frequency used by the OS and is the basis of all timing services.
+ * In general is is better to use mach's or higher level timing services, but this value
+ * is needed to convert the PPC Time Base registers to real time.
+ *
+ * hw.cpufrequency - These values provide the current, min and max cpu frequency. The min and max are for
+ * hw.cpufrequency_max - all power management modes. The current frequency is the max frequency in the current mode.
+ * hw.cpufrequency_min - All frequencies are in Hz.
+ *
+ * hw.busfrequency - These values provide the current, min and max bus frequency. The min and max are for
+ * hw.busfrequency_max - all power management modes. The current frequency is the max frequency in the current mode.
+ * hw.busfrequency_min - All frequencies are in Hz.
+ *
+ * hw.cputype - These values provide the mach-o cpu type and subtype. A complete list is in <mach/machine.h>
+ * hw.cpusubtype - These values should be used to determine what processor family the running cpu is from so that
+ * the best binary can be chosen, or the best dynamic code generated. They should not be used
+ * to determine if a given processor feature is available.
+ * hw.cputhreadtype - This value will be present if the processor supports threads. Like hw.cpusubtype this selector
+ * should not be used to infer features, and only used to name the processors thread architecture.
+ * The values are defined in <mach/machine.h>
+ *
+ * hw.byteorder - Gives the byte order of the processor. 4321 for big endian, 1234 for little.
+ *
+ * hw.pagesize - Gives the size in bytes of the pages used by the processor and VM system.
+ *
+ * hw.cachelinesize - Gives the size in bytes of the processor's cache lines.
+ * This value should be use to control the strides of loops that use cache control instructions
+ * like dcbz, dcbt or dcbst.
+ *
+ * hw.l1dcachesize - These values provide the size in bytes of the L1, L2 and L3 caches. If a cache is not present
+ * hw.l1icachesize - then the selector will return and error.
+ * hw.l2cachesize -
+ * hw.l3cachesize -
+ *
+ *
+ * These are the selectors for optional processor features. Selectors that return errors are not support on the system.
+ * Supported features will return 1 if they are recommended or 0 if they are supported but are not expected to help performance.
+ * Future versions of these selectors may return larger values as necessary so it is best to test for non zero.
+ *
+ * hw.optional.floatingpoint - Floating Point Instructions
+ * hw.optional.altivec - AltiVec Instructions
+ * hw.optional.graphicsops - Graphics Operations
+ * hw.optional.64bitops - 64-bit Instructions
+ * hw.optional.fsqrt - HW Floating Point Square Root Instruction
+ * hw.optional.stfiwx - Store Floating Point as Integer Word Indexed Instructions
+ * hw.optional.dcba - Data Cache Block Allocate Instruction
+ * hw.optional.datastreams - Data Streams Instructions
+ * hw.optional.dcbtstreams - Data Cache Block Touch Steams Instruction Form
+ *
+ */
+
+