linux中应用层访问硬件的方法

来源：互联网发布：java的ip地址校验编辑：程序博客网时间：2024/05/15 01:47

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/mman.h>

int main(int argc, char *argv[])
{
   int fd;
   unsigned long vaddr;
   unsigned long paddr;
   unsigned long value = 0;
   char *endstr;
   int set = 0;

    if(argc == 1)
    {
        printf("usage: reg <set|get> <addr> [value]\n");
        return 1;
    }
    paddr = strtoul(argv[2],&endstr,16);
    if(!strcmp(argv[1],"set"))
    {
        set = 1;
        value = strtoul(argv[3],&endstr,16);
    }
    printf("addr = 0x%08X, value = 0x%08X\n",paddr,value);

    fd = open("/dev/mem", O_RDWR | O_NDELAY);
    if (fd == -1)
    {
        printf("mem dirver open fail\n");
        return 1;
    }
    vaddr = (unsigned long)mmap(0, 0x1000, PROT_READ | PROT_WRITE, MAP_SHARED, fd, paddr&0xfffff000);
    if(set)
        *(unsigned long *)(vaddr+(paddr&0x00000fff)) = value;
    else
        printf("0x%08X\n",*(unsigned long *)(vaddr+(paddr&0xfff)));
    return 0;
}