Armv8-A CPU system register access

Helper crate to access Arm A-profile CPU system registers.

Implemented features

Feature flags

The system registers for each Exception Level are guarded by a corresponding feature flag. Each EL feature implies the lower ELs.

• el3 gives access to all supported system registers.
• el2 gives access to EL2, EL1 and EL0 system registers.
• el1 gives access to EL1 and EL0 system registers.

Without any feature flags only EL0 system registers are included.

For unit testing, the fakes feature can be used. This replaces the assembly code for reading and writing system registers with accesses to a set of fake system registers, stored in fake::SYSREGS.

Future plans

License

The project is MIT and Apache-2.0 dual licensed, see LICENSE-Apache-2.0 and LICENSE-MIT.

Maintainers

arm-sysregs is a trustedfirmware.org maintained project. All contributions are ultimately merged by the maintainers listed below.

• Bálint Dobszay balint.dobszay@arm.com balint-dobszay-arm
• Imre Kis imre.kis@arm.com imre-kis-arm
• Sandrine Afsa sandrine.afsa@arm.com sandrine-bailleux-arm

Contributing

Please follow the directions of the Trusted Firmware Processes

Contributions are handled through review.trustedfirmware.org.

Arm trademark notice

Arm is a registered trademark of Arm Limited (or its subsidiaries or affiliates).

This project uses some of the Arm product, service or technology trademarks, as listed in the Trademark List, in accordance with the Arm Trademark Use Guidelines.

Subsequent uses of these trademarks throughout this repository do not need to be prefixed with the Arm word trademark.

Copyright The arm-sysregs Contributors.