Makefile

CC = gcc
INC = -Iinclude
DIR = bin
BIN = $(DIR)/vbo
PYTHON ?= python3

# minimal RISCV32I VM build
SRC_COMMON = src/riscv32i.c src/utils.c
SRC_MAIN = src/main.c $(SRC_COMMON)

FLAGS = -Wall -Wextra -Werror -g -std=c11 -pedantic

# RISC-V cross toolchain (see the wiki)
RV_PREFIX ?= ~/.local/xPacks/riscv-none-elf-gcc/xpack-riscv-none-elf-gcc-14.2.0-3/bin/riscv-none-elf-
RV_GCC    := $(RV_PREFIX)gcc
RV_OBJCOPY:= $(RV_PREFIX)objcopy

# Example app pipeline
OUT_DIR ?= out
EXAMPLES_DIR ?= examples
APP_SRC ?= $(EXAMPLES_DIR)/hello.c
APP_ELF := $(OUT_DIR)/app.elf
APP_BIN := $(OUT_DIR)/app.bin
APP_IMG := $(OUT_DIR)/app.img
ORIGIN  ?= 0x3000

define ensure_rv_toolchain
	@if ! command -v $(RV_GCC) >/dev/null 2>&1; then \
		echo "[Make] Missing toolchain: $(RV_GCC). See the wiki for info on how to install and add to PATH."; \
		exit 1; \
	fi
	@if ! command -v $(RV_OBJCOPY) >/dev/null 2>&1; then \
		echo "[Make] Missing tool: $(RV_OBJCOPY). Check your riscv-none-elf toolchain installation."; \
		exit 1; \
	fi
endef

EMBED_IMAGE ?=
EMBED_OBJ :=
ifneq ($(strip $(EMBED_IMAGE)),)
EMBED_OBJ := images/vbo_image.o
endif

TEST_DIR = test

.PHONY: all build clean test app image embed run demo distclean test-integration test-all help

all: build

build: $(EMBED_OBJ)
	mkdir -p $(DIR)
	$(CC) $(INC) $(SRC_MAIN) $(EMBED_OBJ) -o $(BIN) $(FLAGS)

images/vbo_image.o: $(EMBED_IMAGE) tools/embed_image.py
	mkdir -p images
	$(PYTHON) tools/embed_image.py --input "$(EMBED_IMAGE)" --output $@

clean:
	rm -f $(BIN)
	rm -f $(TEST_DIR)/test_utils
	rm -f images/vbo_image.o
	rm -rf $(OUT_DIR)
distclean: clean

test: build
	$(CC) $(INC) $(TEST_DIR)/test_utils.c src/utils.c src/riscv32i.c -o $(TEST_DIR)/test_utils $(FLAGS)
	$(TEST_DIR)/test_utils
	rm $(TEST_DIR)/test_utils

	$(CC) $(INC) $(TEST_DIR)/test_riscv32i.c src/riscv32i.c -o $(TEST_DIR)/test_riscv32i $(FLAGS)
	$(TEST_DIR)/test_riscv32i
	rm $(TEST_DIR)/test_riscv32i

	@if ! command -v $(RV_GCC) >/dev/null 2>&1 || ! command -v $(RV_OBJCOPY) >/dev/null 2>&1; then \
	  echo "[Test] Skipping integration test (toolchain not found). See the wiki"; \
	  exit 0; \
	fi
	@$(MAKE) --no-print-directory image
	@out=$$($(BIN) $(APP_IMG)); echo "$$out" | grep -q "Hello from RV32I VM" && echo "OK" || (echo "FAIL"; exit 1)




# --- App build pipeline ---

$(OUT_DIR):
	mkdir -p $(OUT_DIR)

app: $(APP_ELF)

$(APP_ELF): $(APP_SRC) | $(OUT_DIR)
	$(call ensure_rv_toolchain)
	$(RV_GCC) \
	  -march=rv32i -mabi=ilp32 -nostdlib -ffreestanding -Os -s -fno-pic \
	  -Wl,--build-id=none -Wl,-Ttext=$(ORIGIN) -Wl,-e,_start \
	  -Iinclude -o $@ $<

$(APP_BIN): $(APP_ELF) | $(OUT_DIR)
	$(RV_OBJCOPY) -O binary $< $@

image: $(APP_IMG)

$(APP_IMG): $(APP_BIN) | $(OUT_DIR)
	$(PYTHON) -c 'import sys,struct; o=int(sys.argv[1],16) if str(sys.argv[1]).startswith("0x") else int(sys.argv[1]); open(sys.argv[2],"wb").write(struct.pack(">I",o)+open(sys.argv[3],"rb").read())' \
	  $(ORIGIN) $@ $<

# Embed convenience: uses APP_IMG if EMBED_IMAGE not provided
embed: image
	$(MAKE) build EMBED_IMAGE=$(APP_IMG)

run: build image
	$(BIN) $(APP_IMG)

demo: embed run

help:
	@echo "Targets:"
	@echo "  build            - Build the VM"
	@echo "  app              - Build example app (set APP_SRC=...)"
	@echo "  image            - Make flat image with origin header from app"
	@echo "  embed            - Embed image and rebuild VM"
	@echo "  run              - Run VM with built image"
	@echo "  demo             - Build+embed+run example app end-to-end"
	@echo "  test             - Run unit tests"
	@echo "  test-all         - Run unit + integration tests (if toolchain available)"
	@echo "  clean / distclean- Remove build artifacts"