Skip to main content

Milestone 1

Milestone 1 Status​

This milestone is planned.

Background​

The RPMI SYSTEM_IRQ service group was not yet approved during earlier OpenSBI work on Project RP016, which led to use of a VIRQ ECALL extension. The service group has since been approved and merged, providing a standard way to claim pending virtual interrupts through SBI MPXY. OP-TEE-style operating systems also need a yield operation after interrupt handling that can complete the VIRQ flow and, when necessary, return to the previous execution context.

Milestone Description​

Milestone 1 updates OpenSBI interrupt delivery to use the approved RPMI SYSTEM_IRQ service group and adds a Yield ECALL path suitable for operating systems such as OP-TEE.

Requirements​

  • Replace use of the VIRQ ECALL extension for interrupt claiming.
  • Follow the RPMI SYSTEM_IRQ service-group definition.
  • Implement SYSIRQ_CLAIM using the SBI MPXY extension to claim pending virtual interrupts.
  • Implement a Yield ECALL extension that exercises VIRQ completion.
  • Allow the yield path to perform a return context switch when required.

Deliverables​

  • OpenSBI implementation of SYSIRQ_CLAIM over SBI MPXY.
  • OpenSBI implementation of the Yield ECALL extension.
  • Validation that VIRQ completion can return execution to the previous domain when required.