The un union is where processor-specific system page information is kept. The purpose of the union is to serve as a demultiplexing point for the various CPU families. It is demultiplexed based on the value of the type member of the system page structure.
| Member | Processor | type |
|---|---|---|
| x86 | The x86 family | SYSPAGE_X86 |
| ppc | PowerPC family | SYSPAGE_PPC |
| mips | The MIPS family | SYSPAGE_MIPS |
| arm | The ARM family | SYSPAGE_ARM |
| sh | The Hitachi SH family of processors. | SYSPAGE_SH |