docs(fwu): add firmware update documentation
Added firmware update documentation for:
1. PSA firmware update build flag
2. Porting guidelines to set the addresses of FWU metadata image
and updated components in I/O policy
Change-Id: Iad3eb68b4be01a0b5850b69a067c60fcb464f54b
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
diff --git a/docs/getting_started/build-options.rst b/docs/getting_started/build-options.rst
index 2d0d826..901a72a 100644
--- a/docs/getting_started/build-options.rst
+++ b/docs/getting_started/build-options.rst
@@ -873,6 +873,14 @@
This flag is used in defining the firmware update metadata structure. This
flag is by default set to '1'.
+- ``PSA_FWU_SUPPORT``: Enable the firmware update mechanism as per the
+ `PSA FW update specification`_. The default value is 0, and this is an
+ experimental feature.
+ PSA firmware update implementation has some limitations, such as BL2 is
+ not part of the protocol-updatable images, if BL2 needs to be updated, then
+ it should be done through another platform-defined mechanism, and it assumes
+ that the platform's hardware supports CRC32 instructions.
+
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