Big bang

Makefile

@@ -0,0 +1,54 @@
+BUILD_DIR ?= ./build
+SRC_DIRS ?= ./src
+BOOTLOADER_DIR ?= ./asm/boot
+
+SRCS := $(shell find $(SRC_DIRS) -name *.cpp -or -name *.c -or -name *.s)
+OBJS := $(SRCS:%=$(BUILD_DIR)/%.o)
+DEPS := $(OBJS:.o=.d)
+
+INC_DIRS := $(shell find $(SRC_DIRS) -type d)
+INC_FLAGS := $(addprefix -I,$(INC_DIRS))
+
+CPPFLAGS ?= $(INC_FLAGS) -MMD -MP -g -std=c++11 -Wall
+
+# Default makefile target
+all: os-image
+
+run: os-image
+	qemu-system-x86_64 -hda build/os-image.bin
+
+# Builds a bootable x86 image that loads the kernel
+os-image: $(BUILD_DIR)/kernel.bin $(BUILD_DIR)/bootloader.bin
+	cat $(BUILD_DIR)/bootloader.bin $(BUILD_DIR)/kernel.bin > build/os-image.bin
+
+# Builds the binary kernel image with the entry prefix
+$(BUILD_DIR)/kernel.bin: $(BUILD_DIR)/kernel_entry.o $(OBJS)
+	ld -m elf_i386 -o $@ -Ttext 0x1000 --oformat binary $(BUILD_DIR)/kernel_entry.o $(OBJS)
+
+# Builds the x86 -> 32-bit bootloader
+$(BUILD_DIR)/bootloader.bin: $(BOOTLOADER_DIR)/main16.asm
+	cd $(BOOTLOADER_DIR); nasm -f bin -o ../../build/bootloader.bin main16.asm
+
+# Builds the kernel entry object file
+$(BUILD_DIR)/kernel_entry.o: asm/boot.asm
+	$(MKDIR_P) $(dir $@)
+	nasm asm/boot.asm -f elf -o $@
+
+# Build C++ sources
+$(BUILD_DIR)/%.cpp.o: %.cpp
+	$(MKDIR_P) $(dir $@)
+	g++ $(CPPFLAGS) $(CXXFLAGS) -m32 -ffreestanding -c $< -o $@ -fno-pie
+
+# Build C sources
+$(BUILD_DIR)/%.c.o: %.c
+	$(MKDIR_P) $(dir $@)
+	gcc $(CFLAGS) $(CXXFLAGS) -m32 -ffreestanding -c $< -o $@ -fno-pie
+
+# Clean all build objects
+.PHONY: clean
+clean:
+	$(RM) -rf $(BUILD_DIR)
+
+-include $(DEPS)
+
+MKDIR_P ?= mkdir -p