Core Complex

[ben-marshall]

Implement a "core complex" module, which wraps the CPU core with:

• A dual port, tightly coupled RAM.
• A single port, tightly coupled ROM.
• The TRNG / pollentropy entropy source.
• The memory mapped machine timers and counters. See#28.
• The physical memory protection registers, when implemented. See#37.
• An "external" memory port out of the CCX to peripherals in a wider SoC system.

The core-complex wraps the CPU in a "drop-in" style module, containing everything the CPU needs to run. This simplifies the construction of the SoC significantly, and lets people re-use it more easily.

Todo List:

• RAM / ROM modules.
• scarv_ccx_top module.
• Interconnect
  • Arbiter
  • Router
  • Hooks for PMP checks. - Decided PMP will live inside the core level.
  • Memory interface definition.
• Memory mapped IO module for:
  • TRNG access.
  • Memory mapped counters.

[ben-marshall]

Closed with 456866f.