About

Currently EDK2 uses SBI interface to implement timer functionality. It should be enhanced to support SSTC extension if the platform supports it.

Project Scope and Timelines

1) Add a new library to provide an interface to check whether an extension is supported by the platform or not. This is required because Sstc is an optional extension. So, before using stimecmp, it should be confirmed whether the platform supports or not. This new library/interface can be used by many other components in future like CMO, MMU etc wherever there is a need to check for the existence of the extension. The interface needs to parse the ISA string.

2) Use stimecmp instead of SBI call.

Changes slated for end of 2H23.

Components and Repos

Upstream edk2 - https://github.com/tianocore/edk2

MdePkg - For new library

UefiPkg/CpuTimerDxeRiscV64 for stimecmp changes

Stakeholders and Partners

• RISE
  • Intel - Andrei Warkentin
  • Ventana - Tuan Phan

Dependencies

None

Measure of Success

An accepted and tested design and implementation by end of 2H23 (slated for merging).

RISE Requirements

None (not accounting any of existing engineering investment against RISE resources).

Status

Updates

25 May 2023

• Project reported as priority for 2H23