万能的makefile

SHELL := /bin/bash
CROSS := arm-none-eabi-
TARGET := niuboot.elf
C_FLAGS := -c -O0 -g3 -mfpu=vfp -mfloat-abi=soft

AR = $(CROSS)ar
CC = $(CROSS)gcc
CXX = $(CROSS)g++

C_FILES = $(shell find -name *.c)
OBJ_FILES = $(shell echo $(C_FILES) | sed 's/\.c/\.o/g')
INC_FLAGS := $(shell find -name \*.h -printf "-I%h\n" | sort -u)

all: $(TARGET)
    @echo "Make ==$(TARGET)== finished!"

$(TARGET):$(OBJ_FILES)
        $(CC) -o $@ $^
%.o:%.c
     $(CC) $(C_FLAGS) $(INC_FLAGS) $< -o $@

clean:
    @rm -f $(TARGET)  *~; \
    find -name \*.o -exec rm '{}' \;
help:
    @echo "make c into .a library in all sub-directories"
.PHONY: clean help