From dd7ca267e17640b72e4b5201927987297615485c Mon Sep 17 00:00:00 2001 From: Luke Kenneth Casson Leighton Date: Mon, 30 Apr 2018 08:37:26 +0100 Subject: [PATCH] clarify --- isa_conflict_resolution/mvendor_march_warl.mdwn | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/isa_conflict_resolution/mvendor_march_warl.mdwn b/isa_conflict_resolution/mvendor_march_warl.mdwn index 32f2a539b..156f72ff0 100644 --- a/isa_conflict_resolution/mvendor_march_warl.mdwn +++ b/isa_conflict_resolution/mvendor_march_warl.mdwn @@ -26,6 +26,16 @@ main considerations are: * Backwards compatibility. Is the change zero-impact (for existing systems) * Forwards compatibility. Does the change affect (limit) future hardware? +Note that unlike with MISA, state information is **not permitted to be +destroyed** during or by a switch-over. Switch-over to a different +mvendorid-marchid tuple shall have the effect of *purely* disabling certain +instruction encodings and enabling others. + +Note also that during context-switching *all* state of *all* custom +extensions (and variants of the Base Standards) are saved onto the stack, +given that a hart may, at any time, switch between any available +mvendorid-marchid tuples. + ## Compliance It was pointed out early in the discussions that Compliance Testing may -- 2.30.2