【Linux设备驱动程序（第三版）】----获取当前时间

 【Linux设备驱动程序（第三版）】----获取当前时间

jit.c

 

#include <linux/module.h>#include <linux/moduleparam.h>#include <linux/init.h>#include <linux/time.h>#include <linux/timer.h>#include <linux/proc_fs.h>#include <linux/spinlock.h>#include <linux/interrupt.h>#include <asm/hardirq.h>#include <linux/sched.h>//jiffies#include <linux/kernel.h>#include <linux/types.h>//u64#include <linux/fs.h>//file_operations, file#include <linux/completion.h>#include <asm/uaccess.h>//copy_to_user & copy_from_userint jit_currentime(char *buf, char **start, off_t offset, int len, int *eof, void *data){struct timeval tv1;struct timespec tv2;unsigned long j1;u64 j2;j1 = jiffies;j2 = get_jiffies_64();do_gettimeofday(&tv1);tv2 = current_kernel_time();len = 0;len += sprintf(buf,"0x%08lx 0x%016Lx %10i.%06i\n"       "%40i.%09i\n",       j1, j2,       (int) tv1.tv_sec, (int) tv1.tv_usec,       (int) tv2.tv_sec, (int) tv2.tv_nsec);*start = buf;return len;}int __init jit_init(void){printk(KERN_DEBUG "jit_init......");create_proc_read_entry("jit_currentime", 0, NULL, jit_currentime, NULL);return 0;}void __exit jit_exit(void){remove_proc_entry("jit_currentime", NULL);}MODULE_LICENSE("Dual BSD/GPL");module_init(jit_init);module_exit(jit_exit);

Makefile

obj-m:= jit.omodules-objs:= jit.oKDIR:= /usr/src/linux-headers-2.6.31-14-generic/PWD:= $(shell pwd)default: make -C $(KDIR) M=$(PWD) modulesclean: rm -rf *.ko *.mod.c *.mod.o *.o *.markers *.symvers *.order

装载驱动

insmod jit.ko

测试

cat /proc/jit_currentime

输出结果：

0x000d52fd 0x00000001000d52fd 1310097626.455468                              1310097626.4545165480x000d52fd 0x00000001000d52fd 1310097626.455470                              1310097626.4545165480x000d52fd 0x00000001000d52fd 1310097626.455472                              1310097626.4545165480x000d52fd 0x00000001000d52fd 1310097626.455474                              1310097626.4545165480x000d52fd 0x00000001000d52fd 1310097626.455476                              1310097626.4545165480x000d52fd 0x00000001000d52fd 1310097626.455478                              1310097626.4545165480x000d52fd 0x00000001000d52fd 1310097626.455481                              1310097626.4545165480x000d52fd 0x00000001000d52fd 1310097626.455483                              1310097626.4545165480x000d52fd 0x00000001000d52fd 1310097626.455485                              1310097626.4545165480x000d52fd 0x00000001000d52fd 1310097626.455487                              1310097626.4545165480x000d52fd 0x00000001000d52fd 1310097626.455489                              1310097626.4545165480x000d52fd 0x00000001000d52fd 1310097626.455491                              1310097626.4545165480x000d52fd 0x00000001000d52fd 1310097626.455493                              1310097626.4545165480x000d52fd 0x00000001000d52fd 1310097626.455495                              1310097626.4545165480x000d52fd 0x00000001000d52fd 1310097626.455497                              1310097626.4545165480x000d52fd 0x00000001000d52fd 1310097626.455499                              1310097626.4545165480x000d52fd 0x00000001000d52fd 1310097626.455502                              1310097626.4545165480x000d52fd 0x00000001000d52fd 1310097626.455504                              1310097626.454516548

卸载

rmmod jit