From 51b9732fe7cc85c0895039e181e522f4d846d3cd Mon Sep 17 00:00:00 2001
From: Ved Shanbhogue <ved@rivosinc.com>
Date: Sun, 25 Feb 2024 10:15:12 -0600
Subject: Fix error in senvcfg definition

---
 model/riscv_insts_zicsr.sail |  8 ++++----
 model/riscv_sys_regs.sail    | 32 +++++++++++++++++++++++++-------
 2 files changed, 29 insertions(+), 11 deletions(-)

diff --git a/model/riscv_insts_zicsr.sail b/model/riscv_insts_zicsr.sail
index ef9e73e..d106ad2 100644
--- a/model/riscv_insts_zicsr.sail
+++ b/model/riscv_insts_zicsr.sail
@@ -122,10 +122,10 @@ function writeCSR (csr : csreg, value : xlenbits) -> unit = {
     (0x304,  _) => { mie = legalize_mie(mie, value); Some(mie.bits) },
     (0x305,  _) => { Some(set_mtvec(value)) },
     (0x306,  _) => { mcounteren = legalize_mcounteren(mcounteren, value); Some(zero_extend(mcounteren.bits)) },
-    (0x30A, 32) => { menvcfg = legalize_envcfg(menvcfg, menvcfg.bits[63 .. 32] @ value); Some(menvcfg.bits[31 .. 0]) },
-    (0x30A, 64) => { menvcfg = legalize_envcfg(menvcfg, value); Some(menvcfg.bits) },
+    (0x30A, 32) => { menvcfg = legalize_menvcfg(menvcfg, menvcfg.bits[63 .. 32] @ value); Some(menvcfg.bits[31 .. 0]) },
+    (0x30A, 64) => { menvcfg = legalize_menvcfg(menvcfg, value); Some(menvcfg.bits) },
     (0x310, 32) => { Some(mstatush.bits) }, // ignore writes for now
-    (0x31A, 32) => { menvcfg = legalize_envcfg(menvcfg, value @ menvcfg.bits[31 .. 0]); Some(menvcfg.bits[63 .. 32]) },
+    (0x31A, 32) => { menvcfg = legalize_menvcfg(menvcfg, value @ menvcfg.bits[31 .. 0]); Some(menvcfg.bits[63 .. 32]) },
     (0x320,  _) => { mcountinhibit = legalize_mcountinhibit(mcountinhibit, value); Some(zero_extend(mcountinhibit.bits)) },
     (0x340,  _) => { mscratch = value; Some(mscratch) },
     (0x341,  _) => { Some(set_xret_target(Machine, value)) },
@@ -161,7 +161,7 @@ function writeCSR (csr : csreg, value : xlenbits) -> unit = {
     (0x104,  _) => { mie = legalize_sie(mie, mideleg, value); Some(mie.bits) },
     (0x105,  _) => { Some(set_stvec(value)) },
     (0x106,  _) => { scounteren = legalize_scounteren(scounteren, value); Some(zero_extend(scounteren.bits)) },
-    (0x10A,  _) => { senvcfg = legalize_envcfg(senvcfg, zero_extend(value)); Some(senvcfg.bits[sizeof(xlen) - 1 .. 0]) },
+    (0x10A,  _) => { senvcfg = legalize_senvcfg(senvcfg, zero_extend(value)); Some(senvcfg.bits[sizeof(xlen) - 1 .. 0]) },
     (0x140,  _) => { sscratch = value; Some(sscratch) },
     (0x141,  _) => { Some(set_xret_target(Supervisor, value)) },
     (0x142,  _) => { scause.bits = value; Some(scause.bits) },
diff --git a/model/riscv_sys_regs.sail b/model/riscv_sys_regs.sail
index fc20e4a..2ab1771 100644
--- a/model/riscv_sys_regs.sail
+++ b/model/riscv_sys_regs.sail
@@ -766,9 +766,7 @@ function read_seed_csr() -> xlenbits = {
 /* Writes to the seed CSR are ignored */
 function write_seed_csr () -> option(xlenbits) = None()
 
-// menvcfg is 64 bits. senvcfg is SXLEN bits and does not have the two
-// upper fields so for simplicity we can use the same type.
-bitfield Envcfg : bits(64) = {
+bitfield MEnvcfg : bits(64) = {
   // Supervisor TimeCmp Extension
   STCE   : 63,
   // Page Based Memory Types Extension
@@ -787,11 +785,31 @@ bitfield Envcfg : bits(64) = {
   FIOM   : 0,
 }
 
-register menvcfg : Envcfg
-register senvcfg : Envcfg
+bitfield SEnvcfg : xlenbits = {
+  // Cache Block Zero instruction Enable
+  CBZE   : 7,
+  // Cache Block Clean and Flush instruction Enable
+  CBCFE  : 6,
+  // Cache Block Invalidate instruction Enable
+  CBIE   : 5 .. 4,
+  // Reserved WPRI bits.
+  wpri_0 : 3 .. 1,
+  // Fence of I/O implies Memory
+  FIOM   : 0,
+}
+
+register menvcfg : MEnvcfg
+register senvcfg : SEnvcfg
+
+function legalize_menvcfg(o : MEnvcfg, v : bits(64)) -> MEnvcfg = {
+  let v = Mk_MEnvcfg(v);
+  let o = [o with FIOM = if sys_enable_writable_fiom() then v[FIOM] else 0b0];
+  // Other extensions are not implemented yet so all other fields are read only zero.
+  o
+}
 
-function legalize_envcfg(o : Envcfg, v : bits(64)) -> Envcfg = {
-  let v = Mk_Envcfg(v);
+function legalize_senvcfg(o : SEnvcfg, v : xlenbits) -> SEnvcfg = {
+  let v = Mk_SEnvcfg(v);
   let o = [o with FIOM = if sys_enable_writable_fiom() then v[FIOM] else 0b0];
   // Other extensions are not implemented yet so all other fields are read only zero.
   o
-- 
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