From: lkcl <lkcl@web>
Date: Sat, 9 Jul 2022 12:45:01 +0000 (+0100)
Subject: (no commit message)
X-Git-Tag: opf_rfc_ls005_v1~1228
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=b2e3d7b25ac904855e33d3f076bd58c4a0bfa5e5;p=libreriscv.git

---

diff --git a/openpower/sv/remap.mdwn b/openpower/sv/remap.mdwn
index a50538d93..a40fadad2 100644
--- a/openpower/sv/remap.mdwn
+++ b/openpower/sv/remap.mdwn
@@ -349,7 +349,8 @@ When `mm=1`:
 * bits 0-2 of `rmm` indicate an index selecting mi0-mo1
 * bits 3-4 of `rmm` indicate which SVSHAPE 0-3 shall be updated
 * only the selected SVSHAPE is overwritten
-* only the relevant bits in the REMAP SPR are updated
+* only the relevant bits in the REMAP area of SVSTATE are updated
+* REMAP persistence bit is set.
 
 Example 1: if `rmm`=0b10011 then mo0 is selected and SVSHAPE2
 to be updated. REMAP.SVme[3] will be set high and REMAP.mo0
@@ -359,6 +360,15 @@ Example 2: if `rmm`=0b11100 then mo1 is selected and SVSHAPE3
 to be updated. REMAP.SVme[4] will be set high and REMAP.mo1
 set to 3 (SVSHAPE3).
 
+Rough algorithmic form:
+
+    marray = [mi0, mi1, mi2, mo0, mo1]
+    bit = rmm[0:2]
+    idx = rmm[3:4]
+    setup(SVSHAPE[idx])
+    SVSTATE{marray[bit]} = idx
+    SVSTATE.pst = 1
+
 In essence, `mm=0` is intended for use to set as much of the
 REMAP State SPRs as practical with a single instruction,
 whilst `mm=1` is intended to be a little more refined.