docs/components/ven-el3-service.rst

Vendor Specific EL3 Monitor Service Calls
=========================================

This document enumerates and describes the Vendor Specific EL3 Monitor Service
Calls.

These are Service Calls defined by the vendor of the EL3 Monitor.
They are accessed via ``SMC`` ("SMC calls") instruction executed from Exception
Levels below EL3. SMC calls for Vendor Specific EL3 Monitor Services:

-  Follow `SMC Calling Convention`_;
-  Use SMC function IDs that fall in the vendor-specific EL3 range, which are

+---------------------------+--------------------------------------------------+
| SMC Function Identifier   | Service Type                                     |
+===========================+==================================================+
| 0x87000000 - 0x8700FFFF   | SMC32: Vendor Specific EL3 Monitor Service Calls |
+---------------------------+--------------------------------------------------+
| 0xC7000000 - 0xC700FFFF   | SMC64: Vendor Specific EL3 Monitor Service Calls |
+---------------------------+--------------------------------------------------+

Vendor-specific EL3 monitor services are as follows:

+-----------------------------------+-----------------------+---------------------------------------------+
| SMC Function Identifier           | Service Type          | FID's Usage                                 |
+===================================+=======================+=============================================+
| 0x87000010 - 0x8700001F (SMC32)   | DebugFS Interface     | | 0 - 11 are in use                         |
+-----------------------------------+                       | | 12 - 15 are reserved for future expansion |
| 0xC7000010 - 0xC700001F (SMC64)   |                       |                                             |
+-----------------------------------+-----------------------+---------------------------------------------+

Source definitions for vendor-specific EL3 Monitor Service Calls are located in
the ``ven_el3_svc.h`` header file.


DebugFS interface
-----------------

The optional DebugFS interface is accessed through Vendor specific EL3 service. Refer
to :ref:`DebugFS interface` documentation for further details and usage.

--------------

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.. _SMC Calling Convention: https://developer.arm.com/docs/den0028/latest