diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts
index f86cd0d3b27..e95f4631bf2 100644
--- a/arch/sandbox/dts/test.dts
+++ b/arch/sandbox/dts/test.dts
@@ -90,6 +90,16 @@
 			wp-ro {
 				image-pos = <0xf000>;
 				size = <0x1000>;
+				used = <0x884>;
+				compress = "lz4";
+				uncomp-size = <0xcf8>;
+				hash {
+					algo = "sha256";
+					value = [00 01 02 03 04 05 06 07
+						08 09 0a 0b 0c 0d 0e 0f
+						10 11 12 13 14 15 16 17
+						18 19 1a 1b 1c 1d 1e 1f];
+				};
 			};
 			rw {
 				image-pos = <0x10000>;
diff --git a/drivers/core/of_extra.c b/drivers/core/of_extra.c
index 6420e6ec448..653344529e6 100644
--- a/drivers/core/of_extra.c
+++ b/drivers/core/of_extra.c
@@ -14,16 +14,17 @@
 int ofnode_read_fmap_entry(ofnode node, struct fmap_entry *entry)
 {
 	const char *prop;
+	ofnode subnode;
 
 	if (ofnode_read_u32(node, "image-pos", &entry->offset)) {
 		debug("Node '%s' has bad/missing 'image-pos' property\n",
 		      ofnode_get_name(node));
-		return log_ret(-ENOENT);
+		return log_msg_ret("image-pos", -ENOENT);
 	}
 	if (ofnode_read_u32(node, "size", &entry->length)) {
 		debug("Node '%s' has bad/missing 'size' property\n",
 		      ofnode_get_name(node));
-		return log_ret(-ENOENT);
+		return log_msg_ret("size", -ENOENT);
 	}
 	entry->used = ofnode_read_s32_default(node, "used", entry->length);
 	prop = ofnode_read_string(node, "compress");
@@ -31,18 +32,20 @@ int ofnode_read_fmap_entry(ofnode node, struct fmap_entry *entry)
 		if (!strcmp(prop, "lz4"))
 			entry->compress_algo = FMAP_COMPRESS_LZ4;
 		else
-			return log_msg_ret("Unknown compression algo",
-					   -EINVAL);
+			return log_msg_ret("compression algo", -EINVAL);
 	} else {
 		entry->compress_algo = FMAP_COMPRESS_NONE;
 	}
 	entry->unc_length = ofnode_read_s32_default(node, "uncomp-size",
 						    entry->length);
-	prop = ofnode_read_string(node, "hash");
-	if (prop)
-		entry->hash_size = strlen(prop);
-	entry->hash_algo = prop ? FMAP_HASH_SHA256 : FMAP_HASH_NONE;
-	entry->hash = (uint8_t *)prop;
+	subnode = ofnode_find_subnode(node, "hash");
+	if (ofnode_valid(subnode)) {
+		prop = ofnode_read_prop(subnode, "value", &entry->hash_size);
+
+		/* Assume it is sha256 */
+		entry->hash_algo = prop ? FMAP_HASH_SHA256 : FMAP_HASH_NONE;
+		entry->hash = (uint8_t *)prop;
+	}
 
 	return 0;
 }
diff --git a/test/dm/Makefile b/test/dm/Makefile
index afcabfacc1b..e70e50f4024 100644
--- a/test/dm/Makefile
+++ b/test/dm/Makefile
@@ -42,6 +42,7 @@ obj-y += fdtdec.o
 obj-$(CONFIG_UT_DM) += nop.o
 obj-y += ofnode.o
 obj-y += ofread.o
+obj-y += of_extra.o
 obj-$(CONFIG_OSD) += osd.o
 obj-$(CONFIG_DM_VIDEO) += panel.o
 obj-$(CONFIG_DM_PCI) += pci.o
diff --git a/test/dm/of_extra.c b/test/dm/of_extra.c
new file mode 100644
index 00000000000..b19cd3787d8
--- /dev/null
+++ b/test/dm/of_extra.c
@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2021 Google LLC
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dm/of_extra.h>
+#include <dm/test.h>
+#include <test/ut.h>
+#include <u-boot/sha256.h>
+
+static int dm_test_ofnode_read_fmap_entry(struct unit_test_state *uts)
+{
+	const char hash_expect[] = {
+		0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+		0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+		0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+		0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+	};
+	struct fmap_entry entry;
+	ofnode node;
+
+	node = ofnode_path("/cros-ec/flash/wp-ro");
+	ut_assertok(ofnode_read_fmap_entry(node, &entry));
+	ut_asserteq(0xf000, entry.offset);
+	ut_asserteq(0x1000, entry.length);
+	ut_asserteq(0x884, entry.used);
+	ut_asserteq(FMAP_COMPRESS_LZ4, entry.compress_algo);
+	ut_asserteq(0xcf8, entry.unc_length);
+	ut_asserteq(FMAP_HASH_SHA256, entry.hash_algo);
+	ut_asserteq(SHA256_SUM_LEN, entry.hash_size);
+	ut_asserteq_mem(hash_expect, entry.hash, SHA256_SUM_LEN);
+
+	return 0;
+}
+DM_TEST(dm_test_ofnode_read_fmap_entry, 0);