嵌入式

linux动态模块的编译及安装

2019-07-13 05:22发布

站内文章 / 嵌入式Linux
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编译动态的模块加载

为主机编译模块

要编译的模块文件==》hello.c文件：「摘自linux kernel development」 /* * hello.c - The Hello, World! Kernel Module */ #include #include #include /* * hello-init - the init function, called when the module is loaded. * Return zero if successfully loaded, nonzero otherwise. */ static int hello_init(void) { printk(KERN_ALERT "I bear a charmed life. "); return 0; } /* * hello_exit - the exit function, called when the module is removed. */ static void hello_exit (void) { printk(KERN_ALERT "Out, out, brief candle! "); } module_init(hello_init); module_exit(hello_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Shakespeare"); MODULE_DESCRIPTION("A Hello, world Module"); Makefile文件：「摘自linux device driver」 # If KERNELRELEASE is defined, we've been invoked from the # kernel build system and can use its language. ifneq ($(KERNELRELEASE),)     obj-m := hello.o # Otherwise we were called directly from the command # line; invoke the kernel build system. else KERNELDIR ?= /lib/modules/$(shell uname -r)/build  #第一中找内核路径方法 #KERNELDIR ?= /usr/src/"linux-headers-$(shell uname -r)" #第二种找内核路径的方法，实质也是前一种方法的链接 PWD := $(shell pwd) default:     $(MAKE) -C $(KERNELDIR) M=$(PWD) modules       #此处巧妙的运用了 “-C” 实现了二次调用Makefile，注意make前要有”tab“按键 modules_install:     $(MAKE) -C $(KERNELDIR) M=$(PWD) modules_install clean:     $(MAKE) -C $(KERNELDIR) M=$(PWD) clean endif 调试命令： 1238 make 1239 sudo insmod hello.ko #加载模块 1240 dmesg |grep charm #查看模块输出信息 1241 sudo rmmod hello.ko #卸载模块 1243 dmesg | tail -n 3 #查看卸载模块信息 查看模块信息：wiwa@tech:~/sourcecodes/kernel/drivers/char/fishing$ modinfo hello.ko filename: /home/wiwa/sourcecodes/kernel/drivers/char/fishing/hello.ko description: A Hello, world Module author: Shakespeare license: GPL srcversion: 1AE41B6A73B1ED6874F5359 depends: vermagic: 3.13.0-74-generic SMP mod_unload modversions 进阶模块安装： wiwa@tech:~/sourcecodes/kernel/drivers/char/fishing$ sudo make modules_install #模块安装 wiwa@tech:~/sourcecodes/kernel/drivers/char/fishing$ sudo depmod #更新模块依赖表 wiwa@tech:~/sourcecodes/kernel/drivers/char/fishing$ cat /lib/modules/$(uname -r)/modules.dep | tail -n 3 #查看模块依赖表 #多了hello.ko模块 kernel/lib/percpu_test.ko: extra/hello.ko: extra/fishing.ko: wiwa@tech:~/sourcecodes/kernel/drivers/char/fishing$ ls -l /lib/modules/$(uname -r)/extra #查看 多了hell.ko文件 total 8 -rw-r--r-- 1 root root 3816 1月   9 18:06 fishing.ko -rw-r--r-- 1 root root 3812 1月  10 16:21 hello.ko wiwa@tech:~/sourcecodes/kernel/drivers/char/fishing$ sudo modprobe hello #用modprobe加载hello模块 wiwa@tech:~/sourcecodes/kernel/drivers/char/fishing$ sudo modprobe -r hello #移除hello模块

交叉模块编译：

在嵌入式中，宿主机可以为目标板编译模块
编译交叉模块修改Makefile文件为：「摘自linux device driver」 ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- INSTALL_MOD_PATH=/media/wiwa/sys #此处为目标板的系统文件根目录 # If KERNELRELEASE is defined, we've been invoked from the# kernel build system and can use its language. ifneq ($(KERNELRELEASE),)    obj-m := hello.o # Otherwise we were called directly from the command# line; invoke the kernel build system. else KERNELDIR ?= ~/sourcecodes/kernel # ~/sourcecodes/kernel 为目标板linux内核文件夹位置 PWD := $(shell pwd) default:     $(MAKE) -C $(KERNELDIR) M=$(PWD) modules      #此处巧妙的运用了 “-C” 实现了二次调用Makefile，注意make前要有”tab“按键 modules_install: #$(MAKE) -C $(KERNELDIR) M=$(PWD) modules_install clean:  $(MAKE) -C $(KERNELDIR) M=$(PWD) clean endif   
  切换到模块所在目录下，执行以下操作： wiwa@tech:~/sourcecodes/kernel/drivers/char/fishing$ make ## fishing为需要编译的模块文件放置的目录，此处依旧编译上述的“Hello.c”文件 在完成上-步后，可以将编译好的模hello.ko块，拷贝到目标板上执行insmod或rmmod指令。