diff --git a/fdtget.c b/fdtget.c
index c2fbab2..374bee2 100644
--- a/fdtget.c
+++ b/fdtget.c
@@ -254,7 +254,7 @@ static int do_fdtget(struct display_info *disp, const char *filename,
 	const char *prop;
 	int i, node;
 
-	blob = utilfdt_read(filename);
+	blob = utilfdt_read(filename, NULL);
 	if (!blob)
 		return -1;
 
diff --git a/fdtput.c b/fdtput.c
index f2197f5..572d6da 100644
--- a/fdtput.c
+++ b/fdtput.c
@@ -239,7 +239,7 @@ static int do_fdtput(struct display_info *disp, const char *filename,
 	char *blob;
 	int len, ret = 0;
 
-	blob = utilfdt_read(filename);
+	blob = utilfdt_read(filename, NULL);
 	if (!blob)
 		return -1;
 
diff --git a/tests/testutils.c b/tests/testutils.c
index f185133..67b39b0 100644
--- a/tests/testutils.c
+++ b/tests/testutils.c
@@ -160,7 +160,7 @@ int nodename_eq(const char *s1, const char *s2)
 void *load_blob(const char *filename)
 {
 	char *blob;
-	int ret = utilfdt_read_err(filename, &blob);
+	int ret = utilfdt_read_err(filename, &blob, NULL);
 
 	if (ret)
 		CONFIG("Couldn't open blob from \"%s\": %s", filename,
diff --git a/util.c b/util.c
index 12f0614..c689ea7 100644
--- a/util.c
+++ b/util.c
@@ -197,7 +197,7 @@ char get_escape_char(const char *s, int *i)
 	return val;
 }
 
-int utilfdt_read_err(const char *filename, char **buffp)
+int utilfdt_read_err(const char *filename, char **buffp, off_t *len)
 {
 	int fd = 0;	/* assume stdin */
 	char *buf = NULL;
@@ -238,13 +238,15 @@ int utilfdt_read_err(const char *filename, char **buffp)
 		free(buf);
 	else
 		*buffp = buf;
+	if (len)
+		*len = bufsize;
 	return ret;
 }
 
-char *utilfdt_read(const char *filename)
+char *utilfdt_read(const char *filename, off_t *len)
 {
 	char *buff;
-	int ret = utilfdt_read_err(filename, &buff);
+	int ret = utilfdt_read_err(filename, &buff, len);
 
 	if (ret) {
 		fprintf(stderr, "Couldn't open blob from '%s': %s\n", filename,
diff --git a/util.h b/util.h
index 543a173..3c20b15 100644
--- a/util.h
+++ b/util.h
@@ -80,9 +80,10 @@ char get_escape_char(const char *s, int *i);
  * stderr.
  *
  * @param filename	The filename to read, or - for stdin
+ * @param len		If non-NULL, the amount of data we managed to read
  * @return Pointer to allocated buffer containing fdt, or NULL on error
  */
-char *utilfdt_read(const char *filename);
+char *utilfdt_read(const char *filename, off_t *len);
 
 /**
  * Read a device tree file into a buffer. Does not report errors, but only
@@ -91,9 +92,10 @@ char *utilfdt_read(const char *filename);
  *
  * @param filename	The filename to read, or - for stdin
  * @param buffp		Returns pointer to buffer containing fdt
+ * @param len		If non-NULL, the amount of data we managed to read
  * @return 0 if ok, else an errno value representing the error
  */
-int utilfdt_read_err(const char *filename, char **buffp);
+int utilfdt_read_err(const char *filename, char **buffp, off_t *len);
 
 
 /**