examples/rv: Make it easier to use a different memory image

examples/rv/Makefile

@@ -1,4 +1,3 @@
-DEFAULT_TEST ?=
 include etc/Makefile.conf
 
 .DEFAULT_GOAL := all

examples/rv/etc/Makefile.conf

@@ -7,9 +7,12 @@ pass:
 # Makefile.platform.conf is a copy of Makefile.rv32i.conf or Makefile.rv32e.conf
 -include Makefile.platform.conf
 
+MEM_NAME ?= integ/primes
+MEM_PATH ?= $(test_directory)/$(MEM_NAME)
+
 CXXFLAGS := --std=c++17
 CUTTLESIM_DRIVER := rvcore.cuttlesim.cpp
-CUTTLESIM_ARGS := $(default_test).rv32
+CUTTLESIM_ARGS := $(MEM_PATH).rv32
 CUTTLESIM_VCD_SCOPES := TOP top rv_core
 
 # Faster GCOV runs
@@ -18,7 +21,7 @@ CUTTLESIM_COV_FLAGS := -Og -ggdb3
 # Verilator config
 VERILATOR_FLAGS := +define+MEM_ADDRESS_WIDTH=$(mem_address_width) +define+BRAM_RUNTIME_INIT+SIMULATION -CFLAGS -DVL_USER_FINISH
 VERILATOR_DRIVER := rvcore.verilator.cpp
-VERILATOR_ARGS := +VMH=$(default_test).vmh
+VERILATOR_ARGS := +VMH=$(MEM_PATH).vmh
 VERILATOR_WARNINGS := -Wno-fatal
 VERILATOR_TOP := top.v
 # Set prefix to Vtop in all cases, to be able to switch between top and top_uart
@@ -38,5 +41,5 @@ ECP5_PACKAGE := CABGA381
 ECP5_LPF := ulx3s_v20.lpf
 ECP5_FREQUENCY := 25
 
-YOSYS_OPTS := '-DMEM_FILENAME="$(default_test).vmh"' -DMEM_ADDRESS_WIDTH=$(mem_address_width)
+YOSYS_OPTS := '-DMEM_FILENAME="$(MEM_PATH).vmh"' -DMEM_ADDRESS_WIDTH=$(mem_address_width)
 YOSYS_LIBDIRS := .

examples/rv/etc/Makefile.rv32e.conf

@@ -1,2 +1,2 @@
 mem_address_width := 10
-default_test := ../../tests/_build/rv32e/integ/primes
+test_directory := ../../tests/_build/rv32e

examples/rv/etc/Makefile.rv32i.conf

@@ -1,2 +1,2 @@
 mem_address_width := 14
-default_test := ../../tests/_build/rv32i/integ/primes
+test_directory := ../../tests/_build/rv32i