Re: Disabling and re-enabling extensions


Greg Favor
 

A potential second general requirement for all Priv extensions:

- The hart reset state must be fully specified and should generally be UNSPECIFIED except for any key control/status bits that need to be in a specific state.  (This minimizes hardware cost and leaves probably the large majority of state to be initialized by software.)

- The reset state should also specify one of:
    a) The extension is "disabled" (and most, if not all, other extension state is don't care).

    b) The extension is "enabled" and any key control/status bits are initialized to specific values as necessary (with all the rest UNSPECIFIED and left to be initialized by software).

Greg

Join tech-privileged@lists.riscv.org to automatically receive all group messages.