New ISA Extensions

This profile specification introduces the following new extension names for existing features, but none require new features:

  • Ziccif: Main memory supports instruction fetch with atomicity requirement

  • Ziccrse: Main memory supports forward progress on LR/SC sequences

  • Ziccamoa: Main memory supports all atomics in A

  • Zicclsm: Main memory supports misaligned loads/stores

  • Za64rs: Reservation set size of 64 bytes

  • Za128rs: Reservation set size of 128 bytes

  • Zic64b: Cache block size isf 64 bytes

  • Svbare: Bare mode virtual-memory translation supported

  • Svade: Raise exceptions on improper A/D bits

  • Ssccptr: Main memory supports page table reads

  • Sscounterenw: Support writeable enables for any supported counter

  • Sstvecd: stvec supports Direct mode

  • Sstvala: stval provides all needed values

  • Ssu64xl: UXLEN=64 must be supported

  • Ssstateen: Supervisor-mode view of the state-enable extension

  • Shcounterenw: Support writeable enables for any supported counter

  • Shvstvala: vstval provides all needed values

  • Shtvala: htval provides all needed values

  • Shvstvecd: vstvec supports Direct mode

  • Shvsatpa: vsatp supports all modes supported by satp

  • Shgatpa: SvNNx4 mode supported for all modes supported by satp, as well as Bare