openwrt-mt7688 添加应用程序

1、在package下创建自己的工作目录user-apps

cd xxx/openwrt/package

mkdir user-apps

cd user-apps

mkdir helloworld

cd helloworld

mkdir src

2、编写代码（放到src目录）

#include

int main(void)

{

printf(“hello world\n”);

return 0;

}

3、编写编译程序的Makefile（放到src目录）

TARGET := helloworld
#所有源文件
CSRCS = $(wildcard  *.c)
CPPSRCS = $(wildcard *.cpp)

COBJS := $(CSRCS:.c=.o)
CPPOBJS := $(CPPSRCS:.cpp=.o)

CFALGS := -Wall -g -O2 -Werror

all:$(COBJS) $(CPPOBJS)
$(CC) $(LDFLAGS) -o $(TARGET) $(COBJS) $(CPPOBJS) $(LIBS) $(CFLAGS)

$(COBJS) : %.o : %.c
$(CC) -c $< -o $@
$(CPPOBJS) : %.o : %.cpp
$(CPP) -c $< -o $@

clean:
rm -rf $(TARGET)
rm -rf *.o

4、编写模块编译Makefile

#
# Copyright (C) 2007-2010 OpenWrt.org
#
# This is free software, licensed under the GNU General Public License v2.
# See /LICENSE for more information.
#

include $(TOPDIR)/rules.mk

PKG_NAME:=helloworld
PKG_RELEASE:=1
PKG_BUILD_DIR:=$(BUILD_DIR)/user-apps/$(PKG_NAME)$(if $(PKG_VERSION),-$(PKG_VERSION))

# This specifies the directory where we're going to build the program.
# The root build directory, $(BUILD_DIR), is by default the build_mipsel
# directory in your OpenWrt SDK directory

include $(INCLUDE_DIR)/package.mk

define Package/$(PKG_NAME)
SECTION:=utils
CATEGORY:=Utilities
TITLE:=$(PKG_NAME)
DEPENDS:=+libpthread +libpcap
endef

define Package/$(PKG_NAME)/description
$(PKG_NAME)
endef

define Build/Prepare
mkdir -p $(PKG_BUILD_DIR)
$(CP) ./src/* $(PKG_BUILD_DIR)/
endef

#---- 这个决定了最后通过opkg命令，将此ipk安装到设备中的哪个目录?
define Package/$(PKG_NAME)/install
$(INSTALL_DIR) $(1)/bin
$(INSTALL_BIN) $(PKG_BUILD_DIR)/$(PKG_NAME) $(1)/bin/
endef

$(eval $(call BuildPackage,$(PKG_NAME)))

5、返回openwrt的根目录,编写

5.1 make menuconfig

     选中Utilities  --->  helloworld.................................................... helloworld

5.2 单独编译模块

      make package/user-apps/helloworld/compile

      在bin/ramips/packages/base/目录下会找到对应的bin，拷贝到nfs共享目录下.

      在开发板已安装模块

      opkg install helloworld_1_ramips_24kec.ipk --nodeps

      查看已经安装上的模块

      opkg list-installed

      卸载模块

      opkg remove helloworld

      ./helloworld执行

5.3 跟内核一起编译，重新烧录固件，在/bin目录下存在helloworld，./helloworld执行。