Speculative Execution and Timing Predictability in an Open Source RISC-V Core

Alban Gruin (1) , Thomas Carle (1) , Hugues Cassé (1) , Christine Rochange (1)

1 IRIT-TRACES - Groupe de Recherche en Architecture et Compilation pour les systèmes embarqués

We present MINOTAuR, a timing predictable open source RISC-V core based on the Ariane core [28]. We first modify Ariane in order to make it timing predictable following the approach used to design the SIC processor [12]. We prove that the instruction parallelism in the Ariane core does not prevent from enforcing timing predictability. We further relax restrictions by enabling a limited amount of speculative execution and we are still able to formally prove that the core is timing predictable. Experimental results show that the performance is reduced by only 10% on average compared to the original Ariane core.

Mots clés: timing predictability; processor architecture

Domaines: Informatique [cs]

Alban Gruin, Thomas Carle, Hugues Cassé, Christine Rochange. Speculative Execution and Timing Predictability in an Open Source RISC-V Core. IEEE Real-Time Systems Symposium (RTSS 2021), Dec 2021, Dortmund, Germany. pp.393-404, ⟨10.1109/RTSS52674.2021.00043⟩. ⟨hal-03477573⟩