docs: add userguide for realm payload testing
Signed-off-by: Soby Mathew <soby.mathew@arm.com>
Change-Id: Iac306f74d4e3a818bee3609f1f6dfd96661d7343
diff --git a/docs/getting_started/build-options.rst b/docs/getting_started/build-options.rst
index d8ffe8b..a891380 100644
--- a/docs/getting_started/build-options.rst
+++ b/docs/getting_started/build-options.rst
@@ -146,6 +146,14 @@
(RAM) or 1 (non-volatile memory like flash) as test results storage. Default
value is 0, as writing to the flash significantly slows tests down.
+Realm payload specific Build Options
+------------------------------------
+
+- ``TFTF_MAX_IMAGE_SIZE``: The option needs to be either set by the user or
+ by the platform makefile to specify the maximum size of TFTF binary. This
+ is needed so that the Realm payload binary can be appended to TFTF binary
+ via ``make pack_realm`` build command.
+
FWU-specific Build Options
--------------------------