From 4d4001af8dc1625a548c269dfd2b3f4d225b087a Mon Sep 17 00:00:00 2001
From: Alexandre Joannou <aj443@cam.ac.uk>
Date: Wed, 22 May 2019 14:52:06 +0100
Subject: [PATCH] Added toMem/fromMem class methods

---
 CHERICC_Fat.bsv | 17 +++++++++++++----
 CHERICap.bsv    | 10 +++++++---
 2 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/CHERICC_Fat.bsv b/CHERICC_Fat.bsv
index 80e84df..de6574e 100644
--- a/CHERICC_Fat.bsv
+++ b/CHERICC_Fat.bsv
@@ -838,7 +838,7 @@ endfunction
 // ===============================================================================
 // Typeclass instance for interface
 
-typedef Bit#(129) CapMem;
+typedef Bit#(TAdd#(1, CapW)) CapMem;
 
 typedef CapFat CapReg;
 
@@ -847,7 +847,7 @@ typedef struct {
   TempFields tempFields;
 } CapPipe deriving (Bits, FShow);
 
-instance CHERICap #(CapMem, OTypeW, FlagsW, CapAddressW);
+instance CHERICap #(CapMem, OTypeW, FlagsW, CapAddressW, CapW);
   function isValidCap (x);
     CapabilityInMemory capMem = unpack(x);
     return capMem.isCapability;
@@ -879,9 +879,11 @@ instance CHERICap #(CapMem, OTypeW, FlagsW, CapAddressW);
   function almightyCap = error("feature not implemented for this cap type");
   function nullCap = error("feature not implemented for this cap type");
   function validAsType = error("feature not implemented for this cap type");
+  function fromMem = error("feature not implemented for this cap type");
+  function toMem = error("feature not implemented for this cap type");
 endinstance
 
-instance CHERICap #(CapReg, OTypeW, FlagsW, CapAddressW);
+instance CHERICap #(CapReg, OTypeW, FlagsW, CapAddressW, CapW);
   function isValidCap = error("feature not implemented for this cap type");
   function setValidCap = error("feature not implemented for this cap type");
   function getFlags = error("feature not implemented for this cap type");
@@ -906,9 +908,11 @@ instance CHERICap #(CapReg, OTypeW, FlagsW, CapAddressW);
   function almightyCap = defaultCapFat;
   function nullCap = null_cap;
   function validAsType = error("feature not implemented for this cap type");
+  function fromMem = error("feature not implemented for this cap type");
+  function toMem = error("feature not implemented for this cap type");
 endinstance
 
-instance CHERICap #(CapPipe, OTypeW, FlagsW, CapAddressW);
+instance CHERICap #(CapPipe, OTypeW, FlagsW, CapAddressW, CapW);
 
   function isValidCap (x) = x.capFat.isCapability;
 
@@ -1041,6 +1045,11 @@ instance CHERICap #(CapPipe, OTypeW, FlagsW, CapAddressW);
       UInt#(64) otypeMaxUnsigned = unpack(zeroExtend(otype_max));
       return checkTypeUnsigned <= otypeMaxUnsigned;
   endfunction
+
+  function fromMem (x) = cast(pack(x));
+
+  function toMem (x) = unpack(cast(x));
+
 endinstance
 
 instance Cast#(CapMem, CapReg);
diff --git a/CHERICap.bsv b/CHERICap.bsv
index be18bf2..9d8ed5a 100644
--- a/CHERICap.bsv
+++ b/CHERICap.bsv
@@ -78,8 +78,8 @@ typedef enum {
   SEALED_WITH_TYPE
 } Kind deriving (Eq, FShow);
 
-typeclass CHERICap#(type t, numeric type ot, numeric type flg, numeric type n)
-  dependencies (t determines (ot, flg, n));
+typeclass CHERICap#(type t, numeric type ot, numeric type flg, numeric type n, numeric type mem_sz)
+  dependencies (t determines (ot, flg, n, mem_sz));
 
   // Return whether the Capability is valid
   function Bool isValidCap (t cap);
@@ -159,9 +159,13 @@ typeclass CHERICap#(type t, numeric type ot, numeric type flg, numeric type n)
   // Check if a type is valid
   function Bool validAsType (t dummy, Bit#(n) checkType);
 
+  // convert from and to bit memory representation
+  function t fromMem (Tuple2#(Bool, Bit#(mem_sz)) mem_cap);
+  function Tuple2#(Bool, Bit#(mem_sz)) toMem (t cap);
+
 endtypeclass
 
-function Fmt showCHERICap(t cap) provisos (CHERICap#(t, ot, flg, n));
+function Fmt showCHERICap(t cap) provisos (CHERICap#(t, ot, flg, n, mem_sz));
   return $format( "Valid: 0x%0x", isValidCap(cap)) +
          $format(" Perms: 0x%0x", getPerms(cap)) +
          $format(" Kind: ", fshow(getKind(cap))) +