refactor(hw/sim): extract common cocotb make infrastructure into shared mk/ directory

- Split monolithic hw/sim/Makefile into modular include files (mk/cocotb-common.mk, mk/rtl-sources.mk)
- Add per-module test Makefiles (cam_core_banked, cam_read_noise, cam_write_noise, match_engine_pipeline, perf, top)
- Add missing simulation tools (yosys, graphviz, xdot) to devenv.nix
- Fix path handling in sweep_noise.py and test modules to be HASH_BITS-aware

hw/sim/mk/cocotb-common.mk

@@ -0,0 +1,82 @@
+ifndef SIM_ROOT
+$(error SIM_ROOT must be set before including mk/cocotb-common.mk)
+endif
+
+ifndef RTL_ROOT
+$(error RTL_ROOT must be set before including mk/cocotb-common.mk)
+endif
+
+ifndef TOPLEVEL
+$(error TOPLEVEL must be set before including mk/cocotb-common.mk)
+endif
+
+ifndef COCOTB_TEST_MODULES
+$(error COCOTB_TEST_MODULES must be set before including mk/cocotb-common.mk)
+endif
+
+ifndef VERILOG_SOURCES
+$(error VERILOG_SOURCES must be set before including mk/cocotb-common.mk)
+endif
+
+SIM ?= verilator
+TOPLEVEL_LANG ?= verilog
+
+NUM_ROWS ?= 4096
+HASH_BITS ?= 512
+LANES ?= 8
+
+EXTRA_ARGS += +define+NUM_ROWS=$(NUM_ROWS) +define+HASH_BITS=$(HASH_BITS) +define+LANES=$(LANES)
+EXTRA_ARGS += --trace --trace-fst --trace-structs
+
+COMPILE_ARGS += -Wall -Wno-fatal
+COMPILE_ARGS += -I$(RTL_ROOT) -I$(RTL_ROOT)/core -I$(RTL_ROOT)/noise -I$(RTL_ROOT)/random
+COMPILE_ARGS += +define+SIM_DEBUG
+COMPILE_ARGS += $(EXTRA_DEFINES)
+
+WRITE_NOISE_EN          ?= $(NOISE_EN)
+WRITE_NOISE_RATE_NUM    ?= $(NOISE_RATE_NUM)
+WRITE_NOISE_RATE_DEN    ?= $(NOISE_RATE_DEN)
+WRITE_NOISE_BITS        ?= $(NOISE_BITS)
+READ_NOISE_EN           ?=
+READ_NOISE_RATE_NUM     ?=
+READ_NOISE_RATE_DEN     ?=
+READ_NOISE_BITS         ?=
+
+ifneq ($(strip $(WRITE_NOISE_EN)),)
+COMPILE_ARGS += -GWRITE_NOISE_EN=$(WRITE_NOISE_EN)
+endif
+ifneq ($(strip $(WRITE_NOISE_RATE_NUM)),)
+COMPILE_ARGS += -GWRITE_NOISE_RATE_NUM=$(WRITE_NOISE_RATE_NUM)
+endif
+ifneq ($(strip $(WRITE_NOISE_RATE_DEN)),)
+COMPILE_ARGS += -GWRITE_NOISE_RATE_DEN=$(WRITE_NOISE_RATE_DEN)
+endif
+ifneq ($(strip $(WRITE_NOISE_BITS)),)
+COMPILE_ARGS += -GWRITE_NOISE_BITS=$(WRITE_NOISE_BITS)
+endif
+ifneq ($(strip $(READ_NOISE_EN)),)
+COMPILE_ARGS += -GREAD_NOISE_EN=$(READ_NOISE_EN)
+endif
+ifneq ($(strip $(READ_NOISE_RATE_NUM)),)
+COMPILE_ARGS += -GREAD_NOISE_RATE_NUM=$(READ_NOISE_RATE_NUM)
+endif
+ifneq ($(strip $(READ_NOISE_RATE_DEN)),)
+COMPILE_ARGS += -GREAD_NOISE_RATE_DEN=$(READ_NOISE_RATE_DEN)
+endif
+ifneq ($(strip $(READ_NOISE_BITS)),)
+COMPILE_ARGS += -GREAD_NOISE_BITS=$(READ_NOISE_BITS)
+endif
+
+export PYTHONPATH := $(SIM_ROOT):$(PYTHONPATH)
+export QUIET ?= 1
+export VERBOSE ?= 0
+export COCOTB_LOG_LEVEL ?= INFO
+export PYTHONWARNINGS ?= ignore::pytest.PytestDeprecationWarning
+
+SUPPRESS_VERILATOR_WARNINGS ?= 0
+ifeq ($(SUPPRESS_VERILATOR_WARNINGS),1)
+COMPILE_ARGS += -Wno-WIDTHEXPAND
+COMPILE_ARGS += -Wno-UNOPTFLAT
+endif
+
+include $(shell uv run cocotb-config --makefiles)/Makefile.sim

hw/sim/mk/rtl-sources.mk

@@ -0,0 +1,23 @@
+ifndef RTL_ROOT
+$(error RTL_ROOT must be set before including mk/rtl-sources.mk)
+endif
+
+RTL_RANDOM := $(RTL_ROOT)/random/random128.sv
+
+RTL_NOISE_MASK := $(RTL_ROOT)/noise/noise_mask_grouped.sv
+RTL_WRITE_NOISE := $(RTL_NOISE_MASK) $(RTL_RANDOM) $(RTL_ROOT)/noise/cam_write_noise.sv
+RTL_READ_NOISE := $(RTL_NOISE_MASK) $(RTL_RANDOM) $(RTL_ROOT)/noise/cam_read_noise.sv
+
+RTL_CAM_CORE_BANKED := $(RTL_ROOT)/core/cam_core_banked.sv
+RTL_MATCH_ENGINE := \
+  $(RTL_ROOT)/core/popcount_pipeline.sv \
+  $(RTL_ROOT)/core/match_engine_pipeline.sv
+
+RTL_CAM_NOISY := \
+  $(RTL_CAM_CORE_BANKED) \
+  $(RTL_WRITE_NOISE) \
+  $(RTL_READ_NOISE) \
+  $(RTL_MATCH_ENGINE) \
+  $(RTL_ROOT)/cam_noisy.sv
+
+RTL_CAM_TOP := $(RTL_CAM_NOISY) $(RTL_ROOT)/cam_top.sv