Index: sys/powerpc/ofw/ofw_machdep.c
===================================================================
--- sys/powerpc/ofw/ofw_machdep.c
+++ sys/powerpc/ofw/ofw_machdep.c
@@ -297,15 +297,38 @@
 	uint64_t start, end;
 	ssize_t size;
 	struct mem_region initrdmap[1];
+	pcell_t cell[2];
 
 	chosen = OF_finddevice("/chosen");
-	size = OF_getprop(chosen, "linux,initrd-start", &start, sizeof(start));
+
+	size = OF_getencprop(chosen, "linux,initrd-start", cell, sizeof(cell));
 	if (size <= 0)
 		return (asz);
+	if (size == 4)
+		start = cell[0];
+	else if (size == 8)
+		start = (uint64_t)cell[0] << 32 | cell[1];
+	else {
+		/* Invalid value length */
+		printf("WARNING: linux,initrd-start must be either 4 or 8 bytes long\n");
+		return (asz);
+	}
 
-	size = OF_getprop(chosen, "linux,initrd-end", &end, sizeof(end));
+	size = OF_getencprop(chosen, "linux,initrd-end", cell, sizeof(cell));
 	if (size <= 0)
 		return (asz);
+	if (size == 4)
+		end = cell[0];
+	else if (size == 8)
+		end = (uint64_t)cell[0] << 32 | cell[1];
+	else {
+		/* Invalid value length */
+		printf("WARNING: linux,initrd-end must be either 4 or 8 bytes long\n");
+		return (asz);
+	}
+
+	if (end <= start)
+		return (asz);
 
 	initrdmap[0].mr_start = start;
 	initrdmap[0].mr_size = end - start;