diff --git a/arch/powerpc/boot/cuboot-83xx.c b/arch/powerpc/boot/cuboot-83xx.c
index 6cbc20afb4d8bccb28e64337d9cd408eadbec259..9af554eea54be6ea105639e05185b3fe5e221a95 100644
--- a/arch/powerpc/boot/cuboot-83xx.c
+++ b/arch/powerpc/boot/cuboot-83xx.c
@@ -57,7 +57,7 @@ void platform_init(unsigned long r3, unsigned long r4, unsigned long r5,
 
 	memcpy(&bd, (bd_t *)r3, sizeof(bd));
 	loader_info.initrd_addr = r4;
-	loader_info.initrd_size = r4 ? r5 : 0;
+	loader_info.initrd_size = r4 ? r5 - r4 : 0;
 	loader_info.cmdline = (char *)r6;
 	loader_info.cmdline_len = r7 - r6;
 
diff --git a/arch/powerpc/boot/cuboot-85xx.c b/arch/powerpc/boot/cuboot-85xx.c
index f88ba00ac1223393e6ab6aff863b205979f8c007..e2560317f2784f0d904815a4e4db05b87d12ece5 100644
--- a/arch/powerpc/boot/cuboot-85xx.c
+++ b/arch/powerpc/boot/cuboot-85xx.c
@@ -58,7 +58,7 @@ void platform_init(unsigned long r3, unsigned long r4, unsigned long r5,
 
 	memcpy(&bd, (bd_t *)r3, sizeof(bd));
 	loader_info.initrd_addr = r4;
-	loader_info.initrd_size = r4 ? r5 : 0;
+	loader_info.initrd_size = r4 ? r5 - r4 : 0;
 	loader_info.cmdline = (char *)r6;
 	loader_info.cmdline_len = r7 - r6;