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Henrik Hautakoski 2018-10-26 12:29:48 +02:00
commit 2ba17c52bd
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/* mm.c
*
* Copyright (C) 2012,2014 Henrik Hautakoski <henrik.hautakoski@gmail.com>
*
* 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., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*/
#include <stdio.h>
#include <stdlib.h>
#include "mm.h"
#ifndef MEM_SIZE
/* Set a default memory size. (2^16) */
#define MEM_SIZE 65536
#endif
#define EXCEPTION_STRING "Runtime exception: Memory address '%u' is out of bounds.\n"
int16_t* base_addr = NULL;
uint8_t *memory = NULL;
static void check_bounds(uint16_t addr) {
if (addr > MEM_SIZE) {
fprintf(stderr, EXCEPTION_STRING, addr);
exit(1);
}
}
void mm_init() {
base_addr = malloc(MEM_SIZE);
memory = (uint8_t*) base_addr;
}
void mm_exit() {
if (base_addr) {
free(base_addr);
base_addr = NULL;
memory = NULL;
}
}
void mm_sw(uint16_t addr, int16_t value) {
check_bounds(addr);
base_addr[addr] = value;
}
int16_t mm_lw(uint16_t addr) {
check_bounds(addr);
return base_addr[addr];
}