build: add initial Bootloader implementation

Signed-off-by: EnderIce2 <enderice2@protonmail.com>

Bootloader/firmware/aarch64/Makefile

@@ -0,0 +1,64 @@
+define find-sources
+	$(shell find ./ -type f -name '$1' $(shell echo $(foreach board,$(filter-out $(BOARD_TYPE),$(AVAILABLE_BOARDS)), -not -path \"./$(board)/*\")) -print0 | xargs -0)
+endef
+
+S_SOURCES := $(call find-sources,*.S)
+s_SOURCES := $(call find-sources,*.s)
+C_SOURCES := $(call find-sources,*.c)
+
+define find-common-sources
+	$(shell find ../../common -type f -name '$1' -print0 | xargs -0)
+endef
+
+C_COMMON_SOURCES := $(call find-common-sources,*.c)
+
+OBJ = $(s_SOURCES:.s=.o) $(S_SOURCES:.S=.o) $(C_SOURCES:.c=.o) $(C_COMMON_SOURCES:.c=.o)
+
+LDFLAGS = -static -nostdlib -nodefaultlibs -nolibc \
+	-Wl,-static,--no-dynamic-linker,-ztext 	\
+	-zmax-page-size=0x1000					\
+	-Wl,-Map boot.map -fno-pic -fno-pie
+
+CFLAGS :=										\
+	$(INCLUDE_DIR)								\
+	-D__kernel__='1'							\
+	-DGIT_COMMIT='"$(GIT_COMMIT)"'				\
+	-DGIT_COMMIT_SHORT='"$(GIT_COMMIT_SHORT)"'	\
+	-fno-pic -fno-pie -fno-builtin -I../../include
+
+CFLAGS += -mcmodel=large
+LDFLAGS += -T$(BOARD_TYPE)/linker.ld
+
+ifeq ($(DEBUG), 1)
+	CFLAGS += -DDEBUG -ggdb3 -O0 -fdiagnostics-color=always
+#	CFLAGS += -fsanitize=undefined
+	CFLAGS += -fstack-check -fverbose-asm
+	LDFLAGS += -ggdb3 -O0
+	ASFLAGS += -g --gstabs+ --gdwarf-5 -D
+endif # DEBUG
+
+default:
+	$(error Do not run this Makefile directly!)
+
+build: boot.bin
+
+boot.bin: $(OBJ)
+	$(info Linking $@)
+	$(CC) $(LDFLAGS) $(OBJ) -o tmp.elf
+	$(OBJCOPY) tmp.elf -O binary ../../boot.bin
+#	rm tmp.elf
+
+%.o: %.c $(HEADERS)
+	$(info Compiling $<)
+	$(CC) $(CFLAGS) -fstack-protector-all -std=c17 -c $< -o $@
+
+%.o: %.S
+	$(info Compiling $<)
+	$(AS) $(ASFLAGS) -c $< -o $@
+
+%.o: %.s
+	$(info Compiling $<)
+	$(AS) $(ASFLAGS) -c $< -o $@
+
+clean:
+	rm -f $(OBJ) boot.map