+/*
+ * 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)
+ *
+ *
+ */
+
+#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>
+
+#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)
+
+void writemem(address, value, int accesstype) {
+ 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);
+ }
+
+ 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;
+}
+
+void readmem(address, int accesstype)
+{
+ int fd;
+ void *map_base, *virt_addr;
+ unsigned long read_result, writeval;
+ off_t target;
+ int access_type = accesstype;
+
+ target = strtoul(argv[1], 0, 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);
+ }
+}
+