riscv_rve

ISA: ratified RV32E and RV64E

• Status: Merged for Binutils 2.42 (GDB part is pending)
• Branch: riscv-rve
• Tracking PR: #110 (view Pull Request and Diff)
• Mailing List:
  • PATCH v1 (2023-07-25)
  • PATCH v2 (2023-08-31)
  • PATCH v3 (2023-09-05)

Feature Description

Since RV32E and RV64E are ratified, this branch intends to support those along with draft/pre-draft ABIs.

Adding pre-draft LP64E would be a problem on GCC but I bet not on Binutils (ELF flags [to handle on Binutils/GAS] are not very detailed).

Note that this patch set does not reflect the version number of the E base ISA (ratified version 2.0) because the latest ratified specification, "20191213", comes with the draft version 1.9 and adding the version 2.0 with ISA_SPEC_CLASS_DRAFT does not work (due to the default value of DEFAULT_RISCV_ISA_SPEC; note that it cannot be set to "draft").

I think the next unprivileged ISA specification release is the best timing to add E version 2.0 (along with new ISA_SPEC_CLASS_20??????).