diff --git a/tools/buildman/buildman.rst b/tools/buildman/buildman.rst
index 5eda01f..73a1313 100644
--- a/tools/buildman/buildman.rst
+++ b/tools/buildman/buildman.rst
@@ -933,6 +933,12 @@
     For example powerpc-linux-gcc will be noted as a toolchain for 'powerpc'
     and CROSS_COMPILE will be set to powerpc-linux- when using it.
 
+'[toolchain-prefix]' section
+    This can be used to provide the full toolchain-prefix for one or more
+    architectures. The full CROSS_COMPILE prefix must be provided. These
+    typically have a higher priority than matches in the '[toolchain]', due to
+    this prefix.
+
 '[toolchain-alias]' section
     This converts toolchain architecture names to U-Boot names. For example,
     if an x86 toolchains is called i386-linux-gcc it will not normally be