RM7965A-900UI 900 MHz 64-bit Microprocessor Data Sheet
4.15 Virtual to Physical Address Mapping
The E9000 provides three modes of virtual addressing:
user mode
kernel mode
supervisor mode
These modes allow system software to provide a secure environment for user processes. Bits in
the CP0 Status register determine which virtual addressing mode is used. In user mode, the
E9000 provides a single, uniform virtual address space of 256 GB (2 GB in 32-bit mode).
When operating in the kernel mode, four distinct virtual address spaces, totaling 1024 GB
(4 GB in 32-bit mode), are simultaneously available and are differentiated by the high-order bits
of the virtual address.
The E9000 core also supports a supervisor mode in which the virtual address space is 256.5 GB
(2.5 GB in 32-bit mode), divided into three regions based on the high-order bits of the virtual
address. Figure shows the address space layout for 32-bit operations.
Table 7 Kernel Mode Virtual Addressing (32-bit)
0xFFFFFFFF
Kernel virtual address space
(kseg3)
0xE0000000
Mapped, 0.5GB
0xDFFFFFFF
Supervisor virtual address space
(ksseg)
0xC0000000
Mapped, 0.5GB
0xBFFFFFFF
Uncached kernel physical address space
(kseg1)
0xA0000000
Unmapped, 0.5GB
0x9FFFFFFF
Cached kernel physical address space
(kseg0)
0x80000000
Unmapped, 0.5GB
0x7FFFFFFF
User virtual address space
(kuseg)
0x00000000
Mapped, 2.0GB
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Document No.: PMC-2100294, Issue 2
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