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--- devmem2/devmem2.c.orig 2006-08-31 17:21:45.000000000 -0600
+++ devmem2/devmem2.c 2006-09-02 09:09:29.000000000 -0600
@@ -20,7 +20,7 @@
* 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
@@ -38,84 +38,111 @@
#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)
+static inline void *fixup_addr(void *addr, size_t size);
+
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]);
+ void *map_base, *virt_addr;
+ unsigned long read_result, write_val;
+ off_t target;
+ int access_type = 'w';
+ char fmt_str[128];
+ size_t data_size;
+
+ 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\nWARNING: "
+ "Writing or reading memory locations may corrupt your system,\n"
+ "so please use this utility with extreme caution!\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");
+ 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);
+ 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);
+ case 'b':
+ data_size = sizeof(unsigned char);
+ virt_addr = fixup_addr(virt_addr, data_size);
+ read_result = *((unsigned char *)virt_addr);
+ break;
+ case 'h':
+ data_size = sizeof(unsigned short);
+ virt_addr = fixup_addr(virt_addr, data_size);
+ read_result = *((unsigned short *)virt_addr);
+ break;
+ case 'w':
+ data_size = sizeof(unsigned long);
+ virt_addr = fixup_addr(virt_addr, data_size);
+ read_result = *((unsigned long *)virt_addr);
+ break;
+ default:
+ fprintf(stderr, "Illegal data type '%c'.\n", access_type);
+ exit(2);
+ }
+ sprintf(fmt_str, "Read at address 0x%%08lX (%%p): 0x%%0%dlX\n",
+ 2*data_size);
+ printf(fmt_str, (unsigned long)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(argc > 3) {
+ write_val = strtoul(argv[3], 0, 0);
+ switch(access_type) {
+ case 'b':
+ virt_addr = fixup_addr(virt_addr, sizeof(unsigned char));
+ *((unsigned char *)virt_addr) = write_val;
+ read_result = *((unsigned char *)virt_addr);
+ break;
+ case 'h':
+ virt_addr = fixup_addr(virt_addr, sizeof(unsigned short));
+ *((unsigned short *)virt_addr) = write_val;
+ read_result = *((unsigned short *)virt_addr);
+ break;
+ case 'w':
+ virt_addr = fixup_addr(virt_addr, sizeof(unsigned long));
+ *((unsigned long *)virt_addr) = write_val;
+ read_result = *((unsigned long *)virt_addr);
+ break;
}
-
- if(munmap(map_base, MAP_SIZE) == -1) FATAL;
+ sprintf(fmt_str, "Write at address 0x%%08lX (%%p): 0x%%0%dlX, "
+ "readback 0x%%0%dlX\n", 2*data_size, 2*data_size);
+ printf(fmt_str, (unsigned long)target, virt_addr,
+ write_val, read_result);
+ fflush(stdout);
+ }
+
+ if(munmap(map_base, MAP_SIZE) == -1) FATAL;
close(fd);
return 0;
}
+static inline void *fixup_addr(void *addr, size_t size)
+{
+#ifdef FORCE_STRICT_ALIGNMENT
+ unsigned long aligned_addr = (unsigned long)addr;
+ aligned_addr &= ~(size - 1);
+ addr = (void *)aligned_addr;
+#endif
+ return addr;
+}
|
