[ESI] Add hostmem write support to cosim

[teqdruid]

Adds cosim support to both the cosim BSP in PyCDE and the corresponding support in the runtime. As with hostmem reads, write only supports one client and no gearboxing.

Copilot reviewed 5 out of 9 changed files in this pull request and generated no comments.

Files not reviewed (4)

• lib/Dialect/ESI/runtime/cpp/lib/backends/Cosim.cpp: Language not supported
• lib/Dialect/ESI/runtime/cpp/tools/esitester.cpp: Language not supported
• frontends/PyCDE/test/test_esi.py: Evaluated as low risk
• frontends/PyCDE/src/pycde/signals.py: Evaluated as low risk

Comments suppressed due to low confidence (4)

frontends/PyCDE/src/pycde/bsp/common.py:339

• [nitpick] The variable name 'write_req_bundle_type' is ambiguous. It should be renamed to 'write_req_bundle_type_def' to clarify that it is a type definition.

write_req_bundle_type = esi.HostMem.write_req_bundle_type(data_type)

frontends/PyCDE/src/pycde/bsp/common.py:305

• The new functionality for handling write requests should be covered by tests to ensure it works as expected. Specifically, the behavior introduced in the 'build_tagged_write_mux' method should be tested.

def build_tagged_write_mux(ports, reqs: List[esi._OutputBundleSetter]) -> BundleSignal:

frontends/PyCDE/integration_test/esitester.py:130

• Ensure that cmd.offset is of type UInt(32) to avoid type mismatch errors.

write_loc_ce = mmio_xact & cmd.write & (cmd.offset == UInt(32)(0))

frontends/PyCDE/integration_test/esitester.py:127

• [nitpick] Improve the error message in cmd_chan_wire.unwrap to be more descriptive.

cmd, cmd_valid = cmd_chan_wire.unwrap(resp_ready_wire)