Overview

With ARM TruseZone core, the Secure Request Framework (SRF) exists to provide a reusable infastructure for implementing multiple secure operations via a single non-secure-callable entry point.

Through the SRF, the secure world exposes one or more operations, which are roughly equivalent to a function. These operations can be combined into a module - a unit of integration between different entities which wish to expose their operations. For example, the Peripheral Driver Library (PDL) would be one module.

For Dual-Core case, SRF integrate Infineon's interprocessor communication library (MTB-IPC). Secure Request IPC integration provides an implementation of contexts and structures used to store states and signal information over MTB-IPC. And it excutes exposed operation defined in the secure world.

This framework requires the user manage a mtb_srf_config.h file that contains macros for the various modules that use the SRF. The file comes with the default macros for user and PDL module IDs. Should a library be added to the project that uses SRF, that library should generate a relevant error message requesting that its module ID is added to the mtb_srf_config.h file.

These are fully documented in the SRF API Reference Manual.

Features

Provides registeration framework mtb_srf_module_register() for a module in the secure world
Provides an implementation of secure request pool (e.g. mtb_srf_pool_s, mtb_srf_ipc_pool_s), which is composed of multiple secure request objects mtb_srf_request_ns_t, which is called SRF request.
Provides SRF comminucation via non-secure-callable (NSC) within TrustZone core. Calling mtb_srf_request_submit() from the non-secure world, secure world provides memory access checking, permission validation, operation dispatch and execution of exposed operation.
Provides SRF IPC communication between one core (sender) and one TrustZone core (receiver)
- Sender: Transmit an SRF request over IPC mtb_srf_ipc_request_submit()
- Receiver: Receives an SRF request over IPC mtb_srf_ipc_receive_request() and process the SRF request from IPC mtb_srf_ipc_process_request().

More information

For more information, refer to the following documents: