openwrt中添加自定义驱动模块和APP

驱动模块添加：

1：make menuconfig中的 kernel modules

其中的各个配置选项来自于下面目录中的.mk文件

这里以other.mk为对照，后续我们添加的驱动模块，添加到other分支当中

2：建立模块目录，路径是package/kernel/example。mkdir -p package/kernel/example

3：进行package/kernel/example目录，建立Makefile文件，内容如下

#Kernel module exampleinclude $(TOPDIR)/rules.mkinclude $(INCLUDE_DIR)/kernel.mkPKG_NAME:=examplePKG_RELEASE:=1include $(INCLUDE_DIR)/package.mkEXTRA_CFLAGS:= \    $(patsubst CONFIG_%, -DCONFIG_%=1, $(patsubst %=m,%,$(filter %=m,$(EXTRA_KCONFIG)))) \$(patsubst CONFIG_%, -DCONFIG_%=1, $(patsubst %=y,%,$(filter %=y,$(EXTRA_KCONFIG)))) \MAKE_OPTS:=ARCH="$(LINUX_KARCH)" \CROSS_COMPILE="$(TARGET_CROSS)" \SUBDIRS="$(PKG_BUILD_DIR)" \EXTRA_CFLAGS="$(EXTRA_CFLAGS)"define KernelPackage/example  SUBMENU:=Other modules  TITLE:=Support Module for example  # DEPENDS:=@XXX   #如果有依赖，这个名字可去make menuconfig里面找到 Symbol:XXX  FILES:=$(PKG_BUILD_DIR)/example.ko  AUTOLOAD:=$(call AutoLoad,81,example) #系统启动时自动装载endef#PKG_BUILD_DIR：/build_dir/target-mipsel_24kec+dsp_uClibc-0.9.33.2/linux-ramips_mt7621/example #建立 PKG_BUILD_DIR ，并将代码拷贝到此处define Build/Preparemkdir -p $(PKG_BUILD_DIR)/              $(CP) -R ./src/* $(PKG_BUILD_DIR)/endefdefine Build/Compile$(MAKE) -C "$(LINUX_DIR)" $(MAKE_OPTS) CONFIG_EXAMPLE=m modulesendef$(eval $(call KernelPackage,example))

4：在package/kernel/example目录下建立src目录，mkdir -p package/kernel/example/src

5：在package/kernel/example/src目录下建立源码文件example.c和对应的Makefile，Kconfig

example.c

#include <linux/module.h>#include <linux/version.h>#include <linux/kmod.h>static int __init example_init(void){printk("hello example openwrt\n");return 0;}static void __exit example_exit(void){printk("hello example openwrt exit\n");}module_init(example_init);module_exit(example_exit);MODULE_AUTHOR("hello world");MODULE_DESCRIPTION("example driver");MODULE_LICENSE("GPL");MODULE_ALIAS("platform:" DRV_NAME);

Makefile:

obj-${CONFIG_EXAMPLE}+= example.o

Kconfig:

config EXAMPLE    tristate "Just a example"    help    This is a example, for debugging kernel model.    If unsure, say N.

6：在trunk目录make menuconfig-->kernel module-->other module-->kmod-example选中。保存Config后，输入make ./package/kernel/example/compile V=s进行编译

应用程序编译

1：在trunk/package应用目录。参考其他的应用文件。创建helloworld文件夹，并进入。创建Makefile：

############################################### OpenWrt Makefile for helloworld program### Most of the variables used here are defined in# the include directives below. We just need to# specify a basic description of the package,# where to build our program, where to find# the source files, and where to install the# compiled program on the router.## Be very careful of spacing in this file.# Indents should be tabs, not spaces, and# there should be no trailing whitespace in# lines that are not commented.###############################################include $(TOPDIR)/rules.mk# Name and release number of this packagePKG_NAME:=helloworldPKG_RELEASE:=1# 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 directoryPKG_BUILD_DIR := $(BUILD_DIR)/$(PKG_NAME)include $(INCLUDE_DIR)/package.mk# Specify package information for this program.# The variables defined here should be self explanatory.# If you are running Kamikaze, delete the DESCRIPTION# variable below and uncomment the Kamikaze define# directive for the description belowdefine Package/helloworldSECTION:=utilsCATEGORY:=UtilitiesTITLE:=Helloworld -- prints a snarky messageendef# Uncomment portion below for Kamikaze and delete DESCRIPTION variable abovedefine Package/helloworld/descriptionIf you can't figure out what this program does, you're probablybrain-dead and need immediate medical attention.endef# Specify what needs to be done to prepare for building the package.# In our case, we need to copy the source files to the build directory.# This is NOT the default.  The default uses the PKG_SOURCE_URL and the# PKG_SOURCE which is not defined here to download the source from the web.# In order to just build a simple program that we have just written, it is# much easier to do it this way.define Build/Preparemkdir -p $(PKG_BUILD_DIR)$(CP) ./src/* $(PKG_BUILD_DIR)/endefdefine Build/Configureendefdefine Build/Compile$(MAKE) -C $(PKG_BUILD_DIR) \CC="$(TARGET_CC)" \CFLAGS="$(TARGET_CFLAGS) -Wall" \LDFLAGS="$(TARGET_LDFLAGS)"endef# We do not need to define Build/Configure or Build/Compile directives# The defaults are appropriate for compiling a simple program such as this one# Specify where and how to install the program. Since we only have one file,# the helloworld executable, install it by copying it to the /bin directory on# the router. The $(1) variable represents the root directory on the router running# OpenWrt. The $(INSTALL_DIR) variable contains a command to prepare the install# directory if it does not already exist.  Likewise $(INSTALL_BIN) contains the# command to copy the binary file from its current location (in our case the build# directory) to the install directory.define Package/helloworld/install$(INSTALL_DIR) $(1)/bin$(INSTALL_BIN) $(PKG_BUILD_DIR)/helloworld $(1)/bin/endef# This line executes the necessary commands to compile our program.# The above define directives specify all the information needed, but this# line calls BuildPackage which in turn actually uses this information to# build a package.$(eval $(call BuildPackage,helloworld))

2：在helloworld目录创建src文件夹，并进入。创建Makefile和helloworld.c：

# build helloworld executable when user executes "make"helloworld: helloworld.o$(CC) $(LDFLAGS) helloworld.o -o helloworldhelloworld.o: helloworld.c$(CC) $(CFLAGS) -c helloworld.c# remove object files and executable when user executes "make clean"clean:rm *.o helloworld

helloworld.c

#include <stdio.h>#include <unistd.h>#include <stdlib.h>int main(int argc, char**argv){    printf("Hell! O' world, why won't my code compile?\n\n");    return 0;}

3：返回trunk目录，make menuconfig-->Utilities-->helloworld。然后make ./package/helloworld/compile V=s