each ASID change. Using the MMU modes to implement ASIDs hinges on
implementing the global bit efficiently.
- save/restore of the CPU state is not implemented (see machine.c).
-- Improve cpu state handling:
- Step 1) Collect all the TC state in a single struct, so we need only
- a single global pointer for the active TC.
- Step 2) Use only a single TC context as working context, and copy the
- contexts on TC switch. Likewise for FPU contexts.
MIPS64
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