【Milk-V Duo 开发板免费体验】使用makefile交叉编译app

1，新建一个app文件夹，后续的操作我们都在这个文件夹里面进行操作
2，首先我们新建一个makefile文件

#
# Makefile
# WARNING: relies on invocation setting current working directory to Makefile location
# This is done in .vscode/task.json
#
PROJECT 			?= app
MAKEFLAGS 			:= -j $(shell nproc)
SRC_EXT      		:= c
OBJ_EXT				:= o
CC					= ../../../duo/duo-buildroot-sdk/host-tools/gcc/riscv64-elf-x86_64/bin/riscv64-unknown-elf-gcc
# CC					= ../../../duo/duo-buildroot-sdk/host-tools/gcc/riscv64-linux-x86_64/bin/riscv64-unknown-linux-gnu-gcc
# CC					= ../../../duo/duo-buildroot-sdk/host-tools/gcc/riscv64-linux-musl-x86_64/bin/riscv64-unknown-linux-musl-gcc
# CC 					?= gcc

SRC_DIR				:= ./
WORKING_DIR			:= ./build
BUILD_DIR			:= $(WORKING_DIR)/obj
BIN_DIR				:= $(WORKING_DIR)/bin

WARNINGS 			:= -Wall

CFLAGS 				:= -O0 -g $(WARNINGS)

# Add define to allow modification of source
DEFINES				:=

# Include files
INC 				:=
LDLIBS	 			:=
BIN 				:= $(BIN_DIR)/app

COMPILE				= $(CC) $(CFLAGS) $(INC) $(DEFINES)

# Automatically include all source files
SRCS 				:= $(shell find $(SRC_DIR) -type f -name '*.c' -not -path '*/\\.*')
OBJECTS    			:= $(patsubst $(SRC_DIR)%,$(BUILD_DIR)/%,$(SRCS:.$(SRC_EXT)=.$(OBJ_EXT)))

all: default

$(BUILD_DIR)/%.$(OBJ_EXT): $(SRC_DIR)/%.$(SRC_EXT)
	[url=home.php?mod=space&uid=70594]@echo[/url] 'Building project file: $<'
	[url=home.php?mod=space&uid=2293869]@MKDIR[/url] -p $(dir $@)
	@$(COMPILE) -c -o "$@" "$<"

default: $(OBJECTS)
	@mkdir -p $(BIN_DIR)
	$(CC) -o $(BIN) $(OBJECTS) $(LDFLAGS) ${LDLIBS}

clean:
	rm -rf $(WORKING_DIR)

# install: ${BIN}
# 	install -d ${DESTDIR}/usr/lib/${PROJECT}/bin
# 	install $< ${DESTDIR}/usr/lib/${PROJECT}/bin/

3，然后我们写一个简单的app

#include <stdio.h>

int main()
{
    printf("Hello, World! \\n");

    return 0;
}

4，然后物品门直接make编译即可，会在build/bin目录下生成一个app文件

5，将这个文件上传到duo上去，这里我使用scp ./build/bin/app root@192.168.42.1:/root/

6，在duo里面直接运行即可

可以看到已经输出了。

唯一需要注意的是我们需要在makefile里面设置好正确的gcc和正确的gcc路径