beri-io.c

/*-
 * SPDX-License-Identifier: BSD-2-Clause
 * 
 * Copyright (c) 2015-2018 Colin Rothwell
 * Copyright (c) 2015-2018 A. Theodore Markettos
 * 
 * This software was developed by SRI International and the University of
 * Cambridge Computer Laboratory under DARPA/AFRL contract FA8750-10-C-0237
 * ("CTSRD"), as part of the DARPA CRASH research programme.
 * 
 * We acknowledge the support of Arm Ltd.
 * 
 * We acknowledge the support of EPSRC.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <stdint.h>
#include <inttypes.h>
#include <unistd.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>

volatile uint8_t *physmem = 0;

volatile uint8_t *open_io_region(uint64_t address, uint64_t length)
{
    int fd = 0;
    volatile uint8_t *mapped = 0;

    fd = open("/dev/mem", O_RDWR|O_SYNC);
    if (fd == -1) {
        perror("open /dev/mem failed");
        exit(1);
    }
    mapped = (uint8_t *)mmap(0, length, PROT_READ|PROT_WRITE, MAP_SHARED, fd, address);
    if (mapped == MAP_FAILED) {
        perror("mmap failed");
        exit(2);
    }
    return mapped;
}