openwrt中添加自定义内核模块

openwrt中自带一整套包管理机制，正确使用openwrt的包管理机制可有效提高开发效率

本文介绍如何在openwrt中增加一个自定义的内核模块包

1、在package/kernel下创建一个应用程序目录mydrv，并在mydrv下再创建一个src用于存放源码文件

$ cd package/kernel

$ mkdir mydrv

$ cd mydrv

$ mkdir src

2、在mydrv目录下创建Makefile,内容如下

$ cd mydrv/

$ vim Makefile

include $(TOPDIR)/rules.mk
include $(INCLUDE_DIR)/kernel.mk

PKG_NAME:=mydrv
PKG_RELEASE:=1

include $(INCLUDE_DIR)/package.mk

define KernelPackage/$(PKG_NAME)
  SUBMENU:=Other modules
  TITLE:=This is a $(PKG_NAME) driver
  FILES:=$(PKG_BUILD_DIR)/$(PKG_NAME).ko
  AUTOLOAD:=$(call AutoLoad,30,,1)
  KCONFIG:=
endef

define KernelPackage/$(PKG_NAME)/description
This is a $(PKG_NAME) device.
endef

EXTRA_KCONFIG:= \
        CONFIG_MYDRV=m

EXTRA_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)" \
        $(EXTRA_KCONFIG)

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

define Build/Compile
        $(MAKE) -C "$(LINUX_DIR)" \
                $(MAKE_OPTS) \
                modules
endef

$(eval $(call KernelPackage,$(PKG_NAME)))

包名称、版本：

PKG_NAME:=mydrv
PKG_RELEASE:=1

描述：

define KernelPackage/$(PKG_NAME)
  SUBMENU:=Other modules
  TITLE:=This is a $(PKG_NAME) driver
  FILES:=$(PKG_BUILD_DIR)/$(PKG_NAME).ko
  AUTOLOAD:=$(call AutoLoad,30,,1)
  KCONFIG:=
endef

define KernelPackage/$(PKG_NAME)/description
This is a $(PKG_NAME) device.
endef

准备操作：

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

define Build/Compile
        $(MAKE) -C "$(LINUX_DIR)" \
                $(MAKE_OPTS) \
                modules
endef

3、进入src/目录，创建Makefile、Kconfig、mydrv.c

$ cd src/

$ vim Makefile

obj-${CONFIG_MYDRV}+= mydrv.o

$ vim Kconfig

config MYDRV
        tristate "test mydrv"
        help
        This is a example, for debugging kernel model.
        If unsure, say N.
 
  
$ vim mydrv.c
 
  
#include 
#include 

static __init int mydrv_init(void)
{
        printk(KERN_ALERT "helloworld!\n");
        return 0;
}

static __exit void mydrv_exit(void)
{
        printk(KERN_ALERT "helloworld exit!\n");
}

module_init(mydrv_init);
module_exit(mydrv_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Stone");
 
  
4、回到根目录，使用make menuconfig配置mydrv模块
 
  
 $ cd openwrt/
 
  
$ make menuconfig
 
  
kernel modules --->
 
  
     Other modules  --->
 
  
            kmod-mydrv.
 
  
5、在根目录编译模块
 
  
$ cd openwrt/
 
  
$ make package/mydrv/compile V=s
 
  
6、变成成功后可在bin/targets/ramips/mt76x8/packages下看到生成的ipk包
 
  
 
  
7、导入ipk包到设备，使用opkg安装此包
 
  
$ opkg install  kmod-mydrv_4.14.101-1_mipsel_24kc.ipk
 
  
成功安装后即可加载mydrv.ko