Enhanced Virtual Addressing

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Enhanced Virtual Addressing (EVA) is a particular configuration of the Segmentation Control registers to extend the user virtual address space up to 3 GiB (overlapping the traditional placement of kseg0 and kseg1) while also extending the kernel address space down to zero so that it has 3 GiB unmapped and 1 GiB mapped.

Due to the overlap of user/kernel virtual address space, various new instructions are provided for performing user memory operations from kernel mode, which the kernel uses for accessing when it needs to access userland memory.

As of December 2013 Linux EVA support can be found in ImgTec's linux-mti-3.8 and linux-mti-3.10 branches at git://git.linux-mips.org/pub/scm/linux-mti.git