The 32-Bit Address Space

The 32-Bit Address Space

The MIPS processors can operate in one of two address modes: 32-bit and 64-bit. The choice of address mode is independent of other features of the instruction set architecture such as the number of available registers and the precision of integer arithmetic (for example, programs compiled to the n32 binary interface use 32-bit addresses but 64-bit integers). The implications for user programs are documented in manuals listed under "Additional Reading" on page xxxix.

The addressing mode can be switched dynamically; for example, the IRIX kernel can operate with 64-bit addresses, but the kernel can switch to 32-bit address when it dispatches a user program that was compiled for that mode. The 32-bit address space is the range of all addresses that can be used when in 32-bit mode. This space is discussed first because it is simpler and more familiar than the 64-bit space.

Segments of the 32-bit Address Space
Virtual Address Mapping
User Process Space--kuseg
Kernel Virtual Space--kseg2
Cached Physical Memory--kseg0
Uncached Physical Memory--kseg1