[kmac] Rework masked SHA3 core and switch to Trivium-based PRNG implementation

hw/ip/entropy_src/rtl/entropy_src_core.sv

@@ -2582,6 +2582,7 @@ module entropy_src_core import entropy_src_pkg::*; #(
     .rand_early_i    (1'b0),
     .rand_data_i     ('0),
     .rand_aux_i      ('0),
+    .rand_update_o   (),
     .rand_consumed_o (),
 
     // N, S: Used in cSHAKE mode

hw/ip/kmac/data/kmac.hjson

@@ -145,29 +145,29 @@
       desc:    "Width of the hash counter in the entropy"
       local:   "true"
     }
-    { name:    "NumSeedsEntropyLfsr",
+    { name:    "NumSeedsEntropy",
       type:    "int",
-      default: "5",
-      desc:    "Number of words for the LFSR seed used for entropy generation",
+      default: "9",
+      desc:    "Number of words for the PRNG seed used for entropy generation",
       local:   "true"
     }
     { name:      "RndCnstLfsrSeed"
-      desc:      "Compile-time random data for LFSR default seed"
+      desc:      "Compile-time random data for PRNG default seed"
       type:      "kmac_pkg::lfsr_seed_t"
-      randcount: "800"
+      randcount: "288"
       randtype:  "data"
     }
     { name:      "RndCnstLfsrPerm",
-      desc:      "Compile-time random permutation for LFSR output",
+      desc:      "Compile-time random permutation for PRNG output",
       type:      "kmac_pkg::lfsr_perm_t"
       randcount: "800",
       randtype:  "perm",
     }
-    { name:      "RndCnstLfsrFwdPerm",
-      desc:      "Compile-time random permutation for forwarding LFSR state",
-      type:      "kmac_pkg::lfsr_fwd_perm_t"
-      randcount: "32",
-      randtype:  "perm",
+    { name:      "RndCnstBufferLfsrSeed"
+      desc:      "Compile-time random data for PRNG buffer default seed"
+      type:      "kmac_pkg::buffer_lfsr_seed_t"
+      randcount: "800"
+      randtype:  "data"
     }
     { name:      "RndCnstMsgPerm"
       desc:      "Compile-time random permutation for LFSR Message output"
@@ -802,36 +802,30 @@
         }
       ]
     } // R: ENTROPY_REFRESH_THRESHOLD_SHADOWED
-    { multireg: {
-        name: "ENTROPY_SEED"
-        desc: '''Entropy Seed
+    {
+      name: "ENTROPY_SEED"
+      desc: '''Entropy Seed
 
-              Entropy seed registers for the integrated entropy generator.
+            Entropy seed register for the integrated entropy generator.
 
-              If !!CFG_SHADOWED.entropy_mode is set to sw_mode, software first needs to set
-              !!CFG_SHADOWED.entropy_ready and then write the !!ENTROPY_SEED_0 -
-              !!ENTROPY_SEED_4 registers in ascending order. Software writes one 32-bit value
-              to every register which is subsequently loaded into the corresponding 32-bit LFSR
-              chunk of the entropy generator.
+            If !!CFG_SHADOWED.entropy_mode is set to sw_mode, software first needs to set !!CFG_SHADOWED.entropy_ready.
+            Then, software needs to write the !!ENTROPY_SEED register 9 times.
+            Upon each write, the written value is loaded into the corresponding state chunk of the entropy generator.
 
-              After writing all !!ENTROPY_SEED_0 registers, the entropy generator will start
-              its operation. After this point, writing these registers has no longer any
-              effect.
-              '''
-        count: "NumSeedsEntropyLfsr"
-        cname: "KMAC"
-        hwext: "true"
-        hwqe : "true"
-        swaccess: "wo"
-        hwaccess: "hro"
-        fields: [
-          { bits: "31:0"
-            name: "seed"
-            desc: "32-bit chunk of the entropy generator seed"
-          }
-        ]
-      } // R: ENTROPY_SEED
-    } // multireg: ENTROPY_SEED
+            After writing the !!ENTROPY_SEED register 9 times, the entropy generator will start its operation.
+            After this point, writing this register has no longer any effect.
+            '''
+      hwext: "true"
+      hwqe : "true"
+      swaccess: "wo"
+      hwaccess: "hro"
+      fields: [
+        { bits: "31:0"
+          name: "seed"
+          desc: "32-bit chunk of the entropy generator seed"
+        }
+      ]
+    } // R: ENTROPY_SEED
     { multireg: {
         name: "KEY_SHARE0"
         desc: '''KMAC Secret Key