| Abdellatif El Khlifi | 39d383b | 2023-08-04 14:33:40 +0100 | [diff] [blame^] | 1 | # SPDX-License-Identifier: GPL-2.0 |
| 2 | |
| 3 | config ARM_FFA_TRANSPORT |
| 4 | bool "Enable Arm Firmware Framework for Armv8-A driver" |
| 5 | depends on DM && ARM64 |
| 6 | select ARM_SMCCC |
| 7 | select ARM_SMCCC_FEATURES |
| 8 | select LIB_UUID |
| 9 | select DEVRES |
| 10 | help |
| 11 | The Firmware Framework for Arm A-profile processors (FF-A) |
| 12 | describes interfaces (ABIs) that standardize communication |
| 13 | between the Secure World and Normal World leveraging TrustZone |
| 14 | technology. |
| 15 | |
| 16 | The FF-A support in U-Boot is based on FF-A specification v1.0 and uses SMC32 |
| 17 | calling convention. |
| 18 | |
| 19 | FF-A specification: |
| 20 | |
| 21 | https://developer.arm.com/documentation/den0077/a/?lang=en |
| 22 | |
| 23 | In U-Boot FF-A design, FF-A is considered as a discoverable bus. |
| 24 | FF-A bus is discovered using ARM_SMCCC_FEATURES mechanism performed |
| 25 | by the PSCI driver. |
| 26 | The Secure World is considered as one entity to communicate with |
| 27 | using the FF-A bus. |
| 28 | FF-A communication is handled by one device and one instance (the bus). |
| 29 | The FF-A support on U-Boot takes care of all the interactions between Normal |
| 30 | world and Secure World. |
| 31 | |
| 32 | Generic FF-A methods are implemented in the Uclass (arm-ffa-uclass.c). |
| 33 | Arm specific methods are implemented in the Arm driver (arm-ffa.c). |
| 34 | |
| 35 | For more details about the FF-A support, please refer to doc/arch/arm64.ffa.rst |
| 36 | |