linux 读取物理寄存器

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

#include <sys/mman.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>



int main(int argc, void** argv) {

    void* base;

    int fd, reg;



    fd = open("/dev/mem", O_RDWR | O_SYNC);

    if (fd < 0) {

        printf("ERR: device open failed.\n");

        return -1; 

    }   

    

    base = mmap(NULL, 0x1000, PROT_READ, MAP_SHARED, fd, 0x20E0000);

    if (base == 0) {

        printf("ERR: mmap failed.\n");

        close(fd);

        return -1; 

    }   



    if (argc > 1) {

        reg = strtol(argv[1], NULL, 16);

        printf(">>> %08X is %08X\n", 0x20E0000 + reg,  *((unsigned int*)(base + reg)));

    }   

    munmap(base, 0x1000);

    close(fd);

    return 0;

}