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/*
* 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 <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <signal.h>
#include <fcntl.h>
#include <ctype.h>
#include <termios.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <stdint.h>
#include <inttypes.h>
#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;
uint64_t read_result, writeval;
int do_write = 0;
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, [d]oubleword\n"
"\tdata : data to be written\n\n",
argv[0]);
exit(1);
}
target = strtoull(argv[1], 0, 0);
if(argc > 2)
access_type = tolower(argv[2][0]);
if (argc > 3) {
writeval = strtoul(argv[3], 0, 0);
do_write = 1;
}
if((fd = open("/dev/mem", O_RDWR | O_SYNC)) == -1)
FATAL;
/* 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;
virt_addr = map_base + (target & MAP_MASK);
if (!do_write) {
switch(access_type) {
case 'b':
read_result = *((uint8_t *) virt_addr);
break;
case 'h':
read_result = *((uint16_t *) virt_addr);
break;
case 'w':
read_result = *((uint32_t *) virt_addr);
break;
case 'd':
read_result = *((uint64_t *) virt_addr);
break;
default:
fprintf(stderr, "Illegal data type '%c'.\n", access_type);
exit(2);
}
printf("0x%" PRIX64 "\n", read_result);
fflush(stdout);
} else {
switch(access_type) {
case 'b':
*((uint8_t *) virt_addr) = writeval;
read_result = *((uint8_t *) virt_addr);
break;
case 'h':
*((uint16_t *) virt_addr) = writeval;
read_result = *((uint16_t *) virt_addr);
break;
case 'w':
*((uint32_t *) virt_addr) = writeval;
read_result = *((uint32_t *) virt_addr);
break;
case 'd':
*((uint64_t *) virt_addr) = writeval;
read_result = *((uint64_t *) virt_addr);
break;
default:
fprintf(stderr, "Illegal data type '%c'.\n", access_type);
exit(2);
}
printf("0x%" PRIX64 "\n", read_result);
fflush(stdout);
}
if(munmap(map_base, MAP_SIZE) == -1)
FATAL;
close(fd);
return 0;
}
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