devmem2了解一下，源码随便一搜便有。

这里贴出来，方便你使用。/*

* devmem2.c: Simple program to read/write from/to any location in memory.

*

* Copyright (C) 2000, Jan-Derk Bakker (J.D.Bakker@its.tudelft.nl)

*

*

* This software has been developed for the LART computing board

* (http://www.lart.tudelft.nl/). The development has been sponsored by

* the Mobile MultiMedia Communications (http://www.mmc.tudelft.nl/)

* and Ubiquitous Communications (http://www.ubicom.tudelft.nl/)

* projects.

*

* The author can be reached at:

*

* Jan-Derk Bakker

* Information and Communication Theory Group

* Faculty of Information Technology and Systems

* Delft University of Technology

* P.O. Box 5031

* 2600 GA Delft

* The Netherlands

*

*

* This program is free software; you can redistribute it and/or modify

* it under the terms of the GNU General Public License as published by

* the Free Software Foundation; either version 2 of the License, or

* (at your option) any later version.

*

* This program is distributed in the hope that it will be useful,

* but WITHOUT ANY WARRANTY; without even the implied warranty of

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

* GNU General Public License for more details.

*

* You should have received a copy of the GNU General Public License

* along with this program; if not, write to the Free Software

* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

*

*/

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#include

#define FATAL do { fprintf(stderr, "Error at line %d, file %s (%d) [%s]\n", \

__LINE__, __FILE__, errno, strerror(errno)); exit(1); } while(0)

#define MAP_SIZE 4096UL

#define MAP_MASK (MAP_SIZE - 1)

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

int fd;

void *map_base, *virt_addr;

unsigned long read_result, writeval;

off_t target;

int access_type = 'w';

if(argc < 2) {

fprintf(stderr, "\nUsage:\t%s { address } [ type [ data ] ]\n"

"\taddress : memory address to act upon\n"

"\ttype : access operation type : [b]yte, [h]alfword, [w]ord\n"

"\tdata : data to be written\n\n",

argv[0]);

exit(1);

}

target = strtoul(argv[1], 0, 0);

if(argc > 2)

access_type = tolower(argv[2][0]);

if((fd = open("/dev/mem", O_RDWR | O_SYNC)) == -1) FATAL;

printf("/dev/mem opened.\n");

fflush(stdout);

/* Map one page */

map_base = mmap(0, MAP_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd, target & ~MAP_MASK);

if(map_base == (void *) -1) FATAL;

printf("Memory mapped at address %p.\n", map_base);

fflush(stdout);

virt_addr = map_base + (target & MAP_MASK);

switch(access_type) {

case 'b':

read_result = *((unsigned char *) virt_addr);

break;

case 'h':

read_result = *((unsigned short *) virt_addr);

break;

case 'w':

read_result = *((unsigned long *) virt_addr);

break;

default:

fprintf(stderr, "Illegal data type '%c'.\n", access_type);

exit(2);

}

printf("Value at address 0x%X (%p): 0x%X\n", target, virt_addr, read_result);

fflush(stdout);

if(argc > 3) {

writeval = strtoul(argv[3], 0, 0);

switch(access_type) {

case 'b':

*((unsigned char *) virt_addr) = writeval;

read_result = *((unsigned char *) virt_addr);

break;

case 'h':

*((unsigned short *) virt_addr) = writeval;

read_result = *((unsigned short *) virt_addr);

break;

case 'w':

*((unsigned long *) virt_addr) = writeval;

read_result = *((unsigned long *) virt_addr);

break;

}

printf("Written 0x%X; readback 0x%X\n", writeval, read_result);

fflush(stdout);

}

if(munmap(map_base, MAP_SIZE) == -1) FATAL;

close(fd);

return 0;

}

使用：devmem2 { address } [ type [ data ] ]

address : 物理地址

如果是要修改该地址的数据，需要填入下面的参数；如果只是读取，省略即可

type :要访问的数据类型 : [b]yte, [h]alfword, [w]ord

data :想要写入的数据

BestRegards，

HSQ