From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Thu, 26 Apr 2018 08:17:43 +0000 (+0100)
Subject: start filling in
X-Git-Tag: convert-csv-opcode-to-binary~5493
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=d4d882496dfba26f945e7dabc70de693807a0e7e;p=libreriscv.git

start filling in
---

diff --git a/isa_conflict_resolution.mdwn b/isa_conflict_resolution.mdwn
index d72c0a54e..1002440fd 100644
--- a/isa_conflict_resolution.mdwn
+++ b/isa_conflict_resolution.mdwn
@@ -235,6 +235,22 @@ separate page?  review this para?**)
 
 TBD paraphrase and clarify
 
+Coming out of the software-related proposal by Jacob, which hinged on
+the idea of a global gcc / binutils database that kept and coordinated
+architectural encodings, was to quite simply make the mvendorid and
+marchid CSRs have WARL (writeable) characteristics.  For instances
+where mvendorid and marchid are readable, that would be taken to be
+a Standards-mandatory "declaration" that the architecture has *no*
+Custom Extensions.
+
+This incredibly simple non-invasive idea has some unique and distinct
+advantages over other proposals:
+
+* Existing designs - even though the specification is not finalised
+  (but has "frozen" aspects) - would be completely unaffected: the
+  change is to the "wording" of the specification to "retrospectively"
+  fit reality.
+
 >  In an earlier part of the thread someone kindly pointed out that MISA
 > already switches out entire sets of instructions [which interacts at the
 > "decode" phase].  However it was noted after a few days of investigating