1 obj-m:=tiger.o
2
3 CURRENT_PATH:=$(shell pwd)
4 VERSION_NUM:=$(shell uname -r)
5 LINUX_PATH:=/usr/src/linux-headers-$(VERSION_NUM)
6
7
8 all :
9 make -C $(LINUX_PATH) M=$(CURRENT_PATH) modules
10 clean:
11 make -C $(LINUX_PATH) M=$(CURRENT_PATH) clean
1 obj-m:=tiger.o
2
3 CURRENT_PATH:=$(shell pwd)
4 VERSION_NUM:=$(shell uname -r)
5 LINUX_PATH:=/usr/src/linux-headers-$(VERSION_NUM)
6
7
8 all :
9 make -C $(LINUX_PATH) M=$(CURRENT_PATH) modules
10 clean:
11 make -C $(LINUX_PATH) M=$(CURRENT_PATH) clean
（程序的调试,加载和运行，在此不进行说明)
3.首先我们来分析下内核加载模块
在内核加载模块中最重要的的action就是注册中断处理程序。很明显，这一动作是通过request_irq()函数来完成的。
int request_irq(unsigned int irq, irq_handler_t handler,unsigned long flags, const char *devname, void *dev_id)
A.先来分析形参：
第一个参数irq: 表示要分配的中断号。对于一些设备(系统时钟或键盘)它的值是预先固定的，而对于大多数设备来说，这个值是动态确定的。
第二个参数 handler： 表示要挂入到中断请求对列中的中断服务例程， 这个中断服务函数的原型是static irqreturn_t handler(int , void *);
中断处理程序的前缀为static,因为它从来不会被别的文件中的代码直接调用。
第三个参数flags:为标志位。可以取IRQF_DISABLED、IRQF_SHARED和IRQF_SAMPLE_RANDOM之一。在本实例程序中取 IRQF_SHARED，该标志表示多个中断处理程序共享irq中断线。一般某个中断线上的中断服务程序在执行时会屏蔽请求该线的其他中断，如果取 IRQF_DISABLED标志，则在执行该中断服务程序时会屏蔽所有其他的中断。取IRQF_SAMPLE_RANDOM则表示设备可以被看做是事件随见的发生源。
以下是官方解释：
/*
* These flags used only by the kernel as part of the
* irq handling routines.
*
* IRQF_DISABLED - keep irqs disabled when calling the action handler
* IRQF_SAMPLE_RANDOM - irq is used to feed the random generator
* IRQF_SHARED - allow sharing the irq among several devices
* IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur
* IRQF_TIMER - Flag to mark this interrupt as timer interrupt
* IRQF_PERCPU - Interrupt is per cpu
* IRQF_NOBALANCING - Flag to exclude this interrupt from irq balancing
* IRQF_IRQPOLL - Interrupt is used for polling (only the interrupt that is
* registered first in an shared interrupt is considered for
* performance reasons)
*/
#define IRQF_DISABLED 0x00000020
#define IRQF_SAMPLE_RANDOM 0x00000040
#define IRQF_SHARED 0x00000080
#define IRQF_PROBE_SHARED 0x00000100
#define IRQF_TIMER 0x00000200
#define IRQF_PERCPU 0x00000400
#define IRQF_NOBALANCING 0x00000800
#define IRQF_IRQPOLL 0x00001000
/*
* These flags used only by the kernel as part of the
* irq handling routines.
*
* IRQF_DISABLED - keep irqs disabled when calling the action handler
* IRQF_SAMPLE_RANDOM - irq is used to feed the random generator
* IRQF_SHARED - allow sharing the irq among several devices
* IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur
* IRQF_TIMER - Flag to mark this interrupt as timer interrupt
* IRQF_PERCPU - Interrupt is per cpu
* IRQF_NOBALANCING - Flag to exclude this interrupt from irq balancing
* IRQF_IRQPOLL - Interrupt is used for polling (only the interrupt that is
* registered first in an shared interrupt is considered for
* performance reasons)
*/
#define IRQF_DISABLED 0x00000020
#define IRQF_SAMPLE_RANDOM 0x00000040
#define IRQF_SHARED 0x00000080
#define IRQF_PROBE_SHARED 0x00000100
#define IRQF_TIMER 0x00000200
#define IRQF_PERCPU 0x00000400
#define IRQF_NOBALANCING 0x00000800
#define IRQF_IRQPOLL 0x00001000