docs(lfa): update porting guide with LFA platform APIs
Add details about the LFA platform APIs to the porting guide,
providing guidance on their usage and integration.
Change-Id: I34c40726086a70abc16211426887ee5617cbd021
diff --git a/docs/porting-guide.rst b/docs/porting-guide.rst
index 327c67b..3ad3e87 100644
--- a/docs/porting-guide.rst
+++ b/docs/porting-guide.rst
@@ -3771,6 +3771,64 @@
Enabling the MEASURED_BOOT flag adds extra platform requirements. Please refer
to :ref:`Measured Boot Design` for more details.
+Live Firmware Activation Interface
+----------------------------------
+
+Function : plat_get_lfa_image_info()
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+::
+
+ Argument : uint32_t
+ Argument : const uuid_t *
+ Return : uint32_t
+
+This platform API retrieves the image ID of the requested image based
+on its index and provides its corresponding UUID.
+The first parameter specifies the image index, and the second
+parameter is a pointer to the UUID. Return UINT32_MAX(-1) if the
+requested image is not found.
+
+Function : is_plat_fw_update_avail()
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+::
+
+ Argument : uint32_t
+ Return : bool
+
+This platform API checks if the specified image, identified
+by its `image_id`, is available for activation. It returns
+True if available, otherwise, it returns False.
+The first parameter is the `image_id` of the image whose
+availability needs to be checked.
+
+Function : plat_lfa_load_auth_image()
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+::
+
+ Argument : uint32_t
+ Return : int
+
+It is upto the platform to do the load and authentication
+of the given component and return appropriate standard errors
+on load and authentication failures.
+The first parameter is the `image_id` which needs to be loaded
+and authenticated by the platform.
+
+Function : bl31_plat_get_next_update_image_ep_info()
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+::
+
+ Argument : uint32_t
+ Return : entry_point_info *
+
+This function is very similar to the ``bl31_plat_get_next_image_ep_info()``
+but it is used to retrieve the ``entry_point_info`` of the updated image
+that needs to be activated in Live Firmware Activation flow.
+
--------------
*Copyright (c) 2013-2025, Arm Limited and Contributors. All rights reserved.*