diff --git a/Makefile b/Makefile
index 417e298..8151fd1 100644
--- a/Makefile
+++ b/Makefile
@@ -44,7 +44,8 @@
 	id \
 	vmstat \
 	lsof \
-	daemon
+	daemon \
+	devmem
 
 LOCAL_SRC_FILES:= \
 	toolbox.c \
diff --git a/devmem.c b/devmem.c
new file mode 100644
index 0000000..0771912
--- /dev/null
+++ b/devmem.c
@@ -0,0 +1,121 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+typedef unsigned int uint32;
+typedef unsigned short uint16;
+typedef unsigned char uint8;
+
+int devmem_main(int argc, char *argv[]) {
+
+  if (argc < 2 || argc > 4) {
+    fprintf(stderr, "usage: devmem <addr> [default:32|16|8] [data]\n");
+    return 1;
+  }
+
+  off_t addr;
+  uint32 data = 0;
+  int wordsize = 32;
+
+  addr = strtoul(argv[1], NULL, 0);
+  if (errno) {
+    perror("Invalid address specified");
+    return 1;
+  }
+
+  if (argc > 2) {
+    wordsize = strtol(argv[2], NULL, 0);
+
+    if (errno || (wordsize != 32 && wordsize != 16 && wordsize != 8)) {
+      fprintf(stderr, "Invalid wordsize specified\n");
+      return 1;
+    }
+  }
+
+  if (argc == 4) {
+    data = strtoul(argv[3], NULL, 0);
+    if (errno) {
+      perror("Invalid data specified");
+      return 1;
+    }
+  }
+
+
+  int mem_fd;
+  void *base, *offset;
+  long pagesize;
+
+  pagesize = sysconf(_SC_PAGE_SIZE);
+
+  if (pagesize <= 0) {
+    return 1;
+  }
+
+  mem_fd = open("/dev/mem", O_SYNC | O_RDWR);
+  if (mem_fd < 0) {
+    perror("open /dev/mem failed");
+    return 1;
+  }
+
+  base = mmap(NULL, 2*pagesize, PROT_READ | PROT_WRITE,
+              MAP_SHARED | MAP_FIXED, mem_fd, addr & ~(pagesize-1));
+
+  if (base == MAP_FAILED) {
+    perror("mmap failed");
+    return 1;
+  }
+
+  offset = base + (addr & (pagesize-1));
+
+  switch(wordsize) {
+    case 32:
+      fprintf(stdout, "0x%08x\n", *(uint32*)offset);
+      break;
+
+    case 16:
+      fprintf(stdout, "0x%04x\n", *(uint16*)offset);
+      break;
+
+    case 8:
+      fprintf(stdout, "0x%02x\n", *(uint8*)offset);
+      break;
+  }
+
+  if (argc == 4) {
+    switch(wordsize) {
+      case 32:
+        *(uint32*)offset = (uint32)data;
+        fprintf(stdout, "0x%08x\n", *(uint32*)offset);
+        break;
+
+      case 16:
+        *(uint16*)offset = (uint16)data;
+        fprintf(stdout, "0x%04x\n", *(uint16*)offset);
+        break;
+
+      case 8:
+        *(uint8*)offset = (uint8)data;
+        fprintf(stdout, "0x%02x\n", *(uint8*)offset);
+        break;
+    }
+  }
+
+
+  if (munmap(base, 2*pagesize)) {
+    perror("munmap failed");
+    return 1;
+  }
+
+  if (close(mem_fd)) {
+    perror("cannot close /dev/mem");
+    return 1;
+  }
+
+  return 0;
+}