diff --git a/README b/README
index 11e9d31..f704eb3 100644
--- a/README
+++ b/README
@@ -3749,6 +3749,9 @@
 		The memory will be freed (or in fact just forgotton) when
 		U-Boot relocates itself.
 
+		Pre-relocation malloc() is only supported on sandbox
+		at present but is fairly easy to enable for other archs.
+
 - CONFIG_SYS_BOOTM_LEN:
 		Normally compressed uImages are limited to an
 		uncompressed size of 8 MBytes. If this is not enough,