独立编译Ko文件添加方式

1.创建文件夹test,其中包含test.c与编译规则Makefile文件:

2.在test.c中编写:

#include <linux/module.h>       //包含模块加载卸载函数

static int  __init test_init(void)          //模块加载调用函数
{
    printk(KERN_ERR "test init\n");

    return 0;
}

static void  __exit test_exit(void)         //模块卸载调用函数
{
    printk(KERN_ERR "test exit\n");
}

module_init(test_init);
module_exit(test_exit);

MODULE_LICENSE("GPL");                      //模块包含协议
MODULE_AUTHOR("jz");                    //作者
MODULE_DESCRIPTION("test");         //模块描述

3.在Makefile中填写，以x2000_darwin为例：

bhu@bhu-PC:~/work$ cat build/configs/x2000_darwin_factory_defconfig | grep kernel          
APP_kernel_dir=../kernel/kernel-x2000                         //获取kernel路径

KERN_DIR = /home/your_linux/kernel/kernel-x2000 #获取到的kernel绝对路径

obj-m += test.o                             #我们需要编译源文件,将其编译成模块

all:
    make -C $(KERN_DIR) M=`pwd` modules         #编译

.PHONY: clean                                   #将clean声明为伪目标

clean:
    make -C $(KERN_DIR) M=`pwd` modules clean   #清除编译生成的文件

4.进入到test目录下,打开终端,并将编译器添加进环境变量,可以生成模块test.ko文件:

环境变量指定为对应的编译器,这里以x2000_darwin为例

bhu@bhu-PC:~/work$ cat build/configs/x2000_darwin_factory_defconfig | grep toolchain_dir
APP_toolchain_dir=../tools/toolchains/mips-gcc720-glibc229                  //获取编译器路径

cd test
export PATH=/home/your_linux/tools/toolchains/mips-gcc720-glibc229/bin:$PATH #配置环境变量,注意这里使用的是获取到的编译器绝对路径
make 

5.将生成的test.ko推入板子观察效果:

bhu@bhu-PC:~/Desktop/test$ adb push test.ko /usr/data
test.ko: 1 file pushed. 1.0 MB/s (2904 bytes in 0.003s)
bhu@bhu-PC:~/Desktop/test$ adb shell
# cd /usr/data/
# ls
evol                 test.ko
macaddr.txt          wpa_supplicant.conf

6.将模块手动加载进开发板,并用dmesg查看加载模块时的打印:

# insmod test.ko 
# lsmod
Module                  Size  Used by    Tainted: G  
test                     658  0                                              //test模块加载进去
# dmesg | tail
[ 7953.488834] <<-GTP-DEBUG->> [819]pre_touch:01, finger:81.
[ 7953.488841] <<-GTP-DEBUG->> [950] (0)(19, 372)[24]
[ 7953.488848] <<-GTP-DEBUG->> [472]ID:0, X:19, Y:372, W:24
[ 7953.499191] <<-GTP-DEBUG->> [819]pre_touch:01, finger:80.
[ 7953.499199] <<-GTP-DEBUG->> [961]@@@@ touch UP ,pre_pen is 0,pre_finger is 1!
[ 7953.499204] <<-GTP-DEBUG->> [970]Touch Release!
[ 7953.509936] <<-GTP-DEBUG->> [819]pre_touch:00, finger:80.
[ 7953.522234] <<-GTP-DEBUG->> [819]pre_touch:00, finger:80.
[91048.779043] adbd (1066): /proc/1066/oom_adj is deprecated, please use /proc/1066/oom_score_adj instead.
[91098.519476] test init                                                    //test模块加载打印

7.将模块卸载,并查看卸载打印:

# rmmod test.ko

# dmesg | tail

[ 7953.488841] <<-GTP-DEBUG->> [950] (0)(19, 372)[24]
[ 7953.488848] <<-GTP-DEBUG->> [472]ID:0, X:19, Y:372, W:24
[ 7953.499191] <<-GTP-DEBUG->> [819]pre_touch:01, finger:80.
[ 7953.499199] <<-GTP-DEBUG->> [961]@@@@ touch UP ,pre_pen is 0,pre_finger is 1!
[ 7953.499204] <<-GTP-DEBUG->> [970]Touch Release!
[ 7953.509936] <<-GTP-DEBUG->> [819]pre_touch:00, finger:80.
[ 7953.522234] <<-GTP-DEBUG->> [819]pre_touch:00, finger:80.
[91048.779043] adbd (1066): /proc/1066/oom_adj is deprecated, please use /proc/1066/oom_score_adj instead.
[91098.519476] test init
[91405.937885] test exit                                                   //test模块卸载打印