Refactor RV32I code, add RV32I tests, update Makefile, cleanup code

.github/workflows/make-ci.yml

@@ -13,7 +13,26 @@ jobs:
 
     steps:
     - uses: actions/checkout@v5
-    - name: make
-      run: make
-    - name: make test
+    - name: Setup Node.js for xpm
+      uses: actions/setup-node@v4
+      with:
+        node-version: '20'
+    - name: Install xpm and riscv-none-elf toolchain
+      shell: bash
+      run: |
+        set -euox pipefail
+        npm install --location=global xpm@latest
+        mkdir -p .ci-xpm
+        printf '%s\n' '{' \
+          '  "name": "vbo-ci-xpm",' \
+          '  "version": "0.0.0",' \
+          '  "private": true,' \
+          '  "xpack": {}' \
+        '}' > .ci-xpm/package.json
+        ( cd .ci-xpm && xpm install @xpack-dev-tools/riscv-none-elf-gcc@14.2.0-3.1 --verbose )
+        TOOLCHAIN_BIN="$HOME/.local/xPacks/@xpack-dev-tools/riscv-none-elf-gcc/14.2.0-3.1/.content/bin"
+        echo "$TOOLCHAIN_BIN" >> "$GITHUB_PATH"
+        echo "RV_PREFIX=riscv-none-elf-" >> "$GITHUB_ENV"
+        "$TOOLCHAIN_BIN/riscv-none-elf-gcc" --version
+    - name: make test # test incorporates build into it
       run: make test

.gitignore

@@ -71,4 +71,10 @@ test/**/*
 
 *.bin
 *.app
-*.img
+*.img
+
+# latex
+paper/**/*
+!paper/**/*.tex
+!paper/**/*.bib
+!paper/**/*.pdf

Makefile

@@ -11,7 +11,7 @@ SRC_MAIN = src/main.c $(SRC_COMMON)
 
 FLAGS = -Wall -Wextra -Werror -g -std=c11 -pedantic
 
-# RISC-V cross toolchain (see docs/compiler.md)
+# 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
@@ -27,7 +27,7 @@ ORIGIN  ?= 0x3000
 
 define ensure_rv_toolchain
 	@if ! command -v $(RV_GCC) >/dev/null 2>&1; then \
-		echo "[Make] Missing toolchain: $(RV_GCC). See docs/compiler.md to install and add to PATH."; \
+		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 \
@@ -44,7 +44,7 @@ endif
 
 TEST_DIR = test
 
-.PHONY: all build clean test distclean app image embed run demo clean-app test-integration test-all help
+.PHONY: all build clean test app image embed run demo distclean test-integration test-all help
 
 all: build
 
@@ -61,16 +61,26 @@ clean:
 	rm -f $(TEST_DIR)/test_utils
 	rm -f images/vbo_image.o
 	rm -rf $(OUT_DIR)
-
 distclean: clean
 
-test:
+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
 
-# Run both unit and integration tests (integration is skipped if toolchain is missing)
-test-all: test test-integration
+	$(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 ---
 
@@ -104,19 +114,6 @@ run: build image
 
 demo: embed run
 
-clean-app:
-	rm -rf $(OUT_DIR)
-
-# Integration test (optional): requires toolchain, builds hello and checks output
-test-integration: build
-	@if ! command -v $(RV_GCC) >/dev/null 2>&1 || ! command -v $(RV_OBJCOPY) >/dev/null 2>&1; then \
-	  echo "[Test] Skipping integration test (toolchain not found). See docs/compiler.md"; \
-	  exit 0; \
-	fi
-	@$(MAKE) --no-print-directory image
-	@echo "[Test] Running integration test (hello)"
-	@out=$$($(BIN) $(APP_IMG)); echo "$$out" | grep -q "Hello from RV32I VM" && echo "[Test] OK" || (echo "[Test] FAIL"; exit 1)
-
 help:
 	@echo "Targets:"
 	@echo "  build            - Build the VM"

include/riscv32i.h

@@ -69,10 +69,10 @@ static inline int32_t rv32i_sext(uint32_t val, int bits) {
 
 
 // define instructions
-void exec_riscv32i(uint32_t instruction);
+void exec_rv32i(uint32_t instruction);
 
 // functions for all instructions, in the format:
-// void exec_riscv32i_<mnemonic>(uint32_t instruction);
+// void exec_rv32i_<mnemonic>(uint32_t instruction);
 
 /* canonical order:
 addi, slti[u], andi, ori, xori, slli, srli, srai, lui, auipc, // integer register-immediate
@@ -171,46 +171,46 @@ enum
 
 
 // integer register-immediate
-void exec_riscv32i_addi(uint32_t instruction);
-void exec_riscv32i_slti(uint32_t instruction);
-void exec_riscv32i_andi(uint32_t instruction);
-void exec_riscv32i_ori(uint32_t instruction);
-void exec_riscv32i_xori(uint32_t instruction);
-void exec_riscv32i_slli(uint32_t instruction);
-void exec_riscv32i_srli_srai(uint32_t instruction);
-void exec_riscv32i_lui(uint32_t instruction);
-void exec_riscv32i_auipc(uint32_t instruction);
-void exec_riscv32i_sltiu(uint32_t instruction);
+void exec_rv32i_addi(uint32_t instruction);
+void exec_rv32i_slti(uint32_t instruction);
+void exec_rv32i_andi(uint32_t instruction);
+void exec_rv32i_ori(uint32_t instruction);
+void exec_rv32i_xori(uint32_t instruction);
+void exec_rv32i_slli(uint32_t instruction);
+void exec_rv32i_srli_srai(uint32_t instruction);
+void exec_rv32i_lui(uint32_t instruction);
+void exec_rv32i_auipc(uint32_t instruction);
+void exec_rv32i_sltiu(uint32_t instruction);
 // integer register-register
-void exec_riscv32i_add_sub(uint32_t instruction);
-void exec_riscv32i_slt(uint32_t instruction);
-void exec_riscv32i_sltu(uint32_t instruction);
-void exec_riscv32i_and(uint32_t instruction);
-void exec_riscv32i_or(uint32_t instruction);
-void exec_riscv32i_xor(uint32_t instruction);
-void exec_riscv32i_sll(uint32_t instruction);
-void exec_riscv32i_srl_sra(uint32_t instruction);
+void exec_rv32i_add_sub(uint32_t instruction);
+void exec_rv32i_slt(uint32_t instruction);
+void exec_rv32i_sltu(uint32_t instruction);
+void exec_rv32i_and(uint32_t instruction);
+void exec_rv32i_or(uint32_t instruction);
+void exec_rv32i_xor(uint32_t instruction);
+void exec_rv32i_sll(uint32_t instruction);
+void exec_rv32i_srl_sra(uint32_t instruction);
 // unconditional jumps
-void exec_riscv32i_jal(uint32_t instruction);
-void exec_riscv32i_jalr(uint32_t instruction);
+void exec_rv32i_jal(uint32_t instruction);
+void exec_rv32i_jalr(uint32_t instruction);
 // conditional branches
-void exec_riscv32i_beq(uint32_t instruction);
-void exec_riscv32i_bne(uint32_t instruction);
-void exec_riscv32i_blt(uint32_t instruction);
-void exec_riscv32i_bge(uint32_t instruction);
-void exec_riscv32i_bltu(uint32_t instruction);
-void exec_riscv32i_bgeu(uint32_t instruction);
+void exec_rv32i_beq(uint32_t instruction);
+void exec_rv32i_bne(uint32_t instruction);
+void exec_rv32i_blt(uint32_t instruction);
+void exec_rv32i_bge(uint32_t instruction);
+void exec_rv32i_bltu(uint32_t instruction);
+void exec_rv32i_bgeu(uint32_t instruction);
 // load and store
-void exec_riscv32i_load(uint32_t instruction);
-void exec_riscv32i_store(uint32_t instruction);
+void exec_rv32i_load(uint32_t instruction);
+void exec_rv32i_store(uint32_t instruction);
 // memory ordering
-void exec_riscv32i_fence(uint32_t instruction);
+void exec_rv32i_fence(uint32_t instruction);
 // environment call and breakpoints
-void exec_riscv32i_system(uint32_t instruction);
+void exec_rv32i_system(uint32_t instruction);
 
 
 // error handling
-void exec_riscv32i_bad_opcode(uint32_t instruction);
+void exec_rv32i_bad_opcode(uint32_t instruction);
 
 // 
 

include/rv32_syscalls.h

@@ -3,6 +3,8 @@
 // Each wrapper issues an ecall with a7=syscall number and returns a0.
 // On error, the return value is a negative errno (Linux convention).
 
+// ? for a real-world use, it'd be much more efficient to implement a c library (newlib?)
+
 #ifndef RV32_SYSCALLS_H
 #define RV32_SYSCALLS_H
 

src/main.c

@@ -73,7 +73,7 @@ int main(int argc, const char* argv[])
       break;
     }
     rv32i_reg[pc] += 4; // advance to next 32-bit instruction
-    exec_riscv32i(instr);
+    exec_rv32i(instr);
   }
   return 0;
 }