diff --git a/driver/iverilog.man b/driver/iverilog.man
index 05245a5b9..a7a4f743e 100644
--- a/driver/iverilog.man
+++ b/driver/iverilog.man
@@ -66,6 +66,11 @@ other tools.
 .TP 8
 .B -gverilog-ams\fI|-fP-gno-verilog-ams
 Enable or disable (default) support for Verilog-AMS.
+Very little Verilog-AMS specific functionality is currently supported.
+.TP 8
+.B -gsystem-verilog\fI|-fP-gno-system-verilog
+Enable or disable (default) support for SystemVerilog.
+Very little SystemVerilog specific functionality is currently supported.
 .TP 8
 .B -gspecify\fI|\fP-gno-specify
 Enable or disable (default) specify block support. When enabled,
diff --git a/driver/main.c b/driver/main.c
index d53e3ab4c..b97decf7a 100644
--- a/driver/main.c
+++ b/driver/main.c
@@ -626,6 +626,9 @@ int process_generation(const char*name)
       else if (strcmp(name,"system-verilog") == 0)
 	    gen_system_verilog = "system-verilog";
 
+      else if (strcmp(name,"no-system-verilog") == 0)
+	    gen_verilog_ams = "no-system-verilog";
+
       else {
 	    fprintf(stderr, "Unknown/Unsupported Language generation "
 		    "%s\n\n", name);
@@ -636,6 +639,7 @@ int process_generation(const char*name)
 		            "Other generation flags:\n"
 		            "    specify | no-specify\n"
 		            "    verilog-ams | no-verilog-ams\n"
+		            "    system-verilog | no-system-verilog\n"
 		            "    std-include | no-std-include\n"
 		            "    relative-include | no-relative-include\n"
 		            "    xtypes | no-xtypes\n"
diff --git a/elab_pexpr.cc b/elab_pexpr.cc
index b7e243341..59849ee37 100644
--- a/elab_pexpr.cc
+++ b/elab_pexpr.cc
@@ -207,6 +207,14 @@ NetExpr*PEIdent::elaborate_pexpr(Design*des, NetScope*scope) const
       name_component_t name_tail = path_.back();
       oldpath.pop_back();
 
+      if (path_.size() > 1) {
+	    cerr << get_fileline() << ": error: parameter r-value expression "
+	            "does not support hierarchical references `" << path_
+	         << "`." << endl;
+	    des->errors += 1;
+	    return 0;
+      }
+
       NetScope*pscope = scope;
       if (path_.size() > 0) {
 	    list<hname_t> tmp = eval_scope_path(des, scope, oldpath);
@@ -229,8 +237,9 @@ NetExpr*PEIdent::elaborate_pexpr(Design*des, NetScope*scope) const
 	    ivl_assert(*this, pscope);
       }
       if (ex == 0) {
-	    cerr << get_fileline() << ": error: identifier ``" << name_tail.name <<
-		  "'' is not a parameter in "<< scope_path(scope)<< "." << endl;
+	    cerr << get_fileline() << ": error: identifier `"
+	         << name_tail.name << "` is not a parameter in "
+	         << scope_path(scope)<< "." << endl;
 	    des->errors += 1;
 	    return 0;
       }
diff --git a/ivlpp/lexor.lex b/ivlpp/lexor.lex
index a6e652c5e..875e40050 100644
--- a/ivlpp/lexor.lex
+++ b/ivlpp/lexor.lex
@@ -1353,10 +1353,17 @@ static void do_expand(int use_args)
         struct include_stack_t*isp;
         int head = 0;
         int tail = 0;
+        const char *cp;
+        unsigned escapes = 0;
+        char *str_buf = 0;
 
         if (cur_macro->keyword)
         {
             fprintf(yyout, "%s", cur_macro->value);
+	    if (do_expand_stringify_flag) {
+		do_expand_stringify_flag = 0;
+		fputc('"', yyout);
+	    }
             return;
         }
 
@@ -1385,6 +1392,43 @@ static void do_expand(int use_args)
             isp->ebs = 0;
         }
 
+        /* Escape some characters if we are making a string version. */
+        for (cp = isp->str; (cp = strpbrk(cp, "\"\\")); cp += 1, escapes += 1);
+        if (escapes && isp->stringify_flag) {
+            unsigned idx = 0;
+            str_buf = (char *) malloc(strlen(isp->str)+3*escapes+1);
+            for (cp = isp->str; *cp; cp += 1) {
+                if (*cp == '"') {
+                   str_buf[idx] = '\\';
+                   str_buf[idx+1] = '0';
+                   str_buf[idx+2] = '4';
+                   str_buf[idx+3] = '2';
+                   idx += 4; 
+                   continue; 
+                }
+                if (*cp == '\\') {
+                   str_buf[idx] = '\\';
+                   str_buf[idx+1] = '1';
+                   str_buf[idx+2] = '3';
+                   str_buf[idx+3] = '4';
+                   idx += 4; 
+                   continue; 
+                }
+                str_buf[idx] = *cp;
+                idx += 1; 
+            }
+            str_buf[idx] = 0;
+            idx += 1;
+            if (use_args) exp_buf_free += isp->ebs;
+            exp_buf_grow_to_fit(idx);
+            head = exp_buf_size - exp_buf_free;
+            exp_buf_free -= idx;
+            strcpy(&exp_buf[head], str_buf);
+            isp->str = &exp_buf[head];
+            isp->ebs = idx;
+            free(str_buf);
+        }
+
         isp->next = istack;
         istack->yybs = YY_CURRENT_BUFFER;
         istack = isp;
@@ -1808,4 +1852,5 @@ void destroy_lexor()
 #   endif
 # endif
     free(def_buf);
+    free(exp_buf);
 }
diff --git a/netmisc.cc b/netmisc.cc
index 4840ca0f2..183d9d47e 100644
--- a/netmisc.cc
+++ b/netmisc.cc
@@ -416,6 +416,7 @@ const char *human_readable_op(const char op, bool unary)
 	    case '-': type = "-";  break;
 	    case '*': type = "*";  break;
 	    case '/': type = "/";  break;
+	    case '%': type = "%";  break;
 
 	    case '<': type = "<";  break;
 	    case '>': type = ">";  break;
diff --git a/parse.y b/parse.y
index 24ef79d2d..764d99ffc 100644
--- a/parse.y
+++ b/parse.y
@@ -80,6 +80,22 @@ static stack<PBlock*> current_block_stack;
 const static struct str_pair_t pull_strength = { PGate::PULL,  PGate::PULL };
 const static struct str_pair_t str_strength = { PGate::STRONG, PGate::STRONG };
 
+static list<pair<perm_string,PExpr*> >* make_port_list(char*id, PExpr*expr)
+{
+      list<pair<perm_string,PExpr*> >*tmp = new list<pair<perm_string,PExpr*> >;
+      tmp->push_back(make_pair(lex_strings.make(id), expr));
+      delete[]id;
+      return tmp;
+}
+static list<pair<perm_string,PExpr*> >* make_port_list(list<pair<perm_string,
+                                                                 PExpr*> >*tmp,
+                                                       char*id, PExpr*expr)
+{
+      tmp->push_back(make_pair(lex_strings.make(id), expr));
+      delete[]id;
+      return tmp;
+}
+
 static list<perm_string>* list_from_identifier(char*id)
 {
       list<perm_string>*tmp = new list<perm_string>;
@@ -146,6 +162,9 @@ static PECallFunction*make_call_function(perm_string tn, PExpr*arg1, PExpr*arg2)
 	   strdup. They can be put into lists with the texts type. */
       char*text;
       list<perm_string>*perm_strings;
+
+      list<pair<perm_string,PExpr*> >*port_list;
+
       pform_name_t*pform_name;
 
       ivl_discipline_t discipline;
@@ -260,7 +279,9 @@ static PECallFunction*make_call_function(perm_string tn, PExpr*arg1, PExpr*arg2)
 %type <expr>    udp_initial_expr_opt
 
 %type <text> register_variable net_variable real_variable
-%type <perm_strings> register_variable_list net_variable_list real_variable_list list_of_identifiers
+%type <perm_strings> register_variable_list net_variable_list
+%type <perm_strings> real_variable_list list_of_identifiers
+%type <port_list> list_of_port_identifiers
 
 %type <net_decl_assign> net_decl_assign net_decl_assigns
 
@@ -1647,6 +1668,17 @@ list_of_identifiers
                 { $$ = list_from_identifier($1, $3); }
 	;
 
+list_of_port_identifiers
+	: IDENTIFIER
+                { $$ = make_port_list($1, 0); }
+	| IDENTIFIER '=' expression
+                { $$ = make_port_list($1, $3); }
+	| list_of_port_identifiers ',' IDENTIFIER
+                { $$ = make_port_list($1, $3, 0); }
+	| list_of_port_identifiers ',' IDENTIFIER '=' expression
+                { $$ = make_port_list($1, $3, $5); }
+	;
+
 
   /* The list_of_ports and list_of_port_declarations rules are the
      port list formats for module ports. The list_of_ports_opt rule is
@@ -1991,9 +2023,20 @@ module_item
 		                 SR_BOTH);
 		}
 
-	| K_output var_type signed_opt range_opt list_of_identifiers ';'
-		{ pform_makewire(@1, $4, $3, $5, $2, NetNet::POUTPUT,
-				 IVL_VT_NO_TYPE, 0, SR_BOTH);
+	| K_output var_type signed_opt range_opt list_of_port_identifiers ';'
+		{ list<pair<perm_string,PExpr*> >::const_iterator pp;
+		  list<perm_string>*tmp = new list<perm_string>;
+		  for (pp = $5->begin(); pp != $5->end(); pp++) {
+			tmp->push_back((*pp).first);
+		  }
+		  pform_makewire(@1, $4, $3, tmp, $2, NetNet::POUTPUT,
+		                 IVL_VT_NO_TYPE, 0, SR_BOTH);
+		  for (pp = $5->begin(); pp != $5->end(); pp++) {
+			if ((*pp).second) {
+			      pform_make_reginit(@1, (*pp).first, (*pp).second);
+			}
+		  }
+		  delete $5;
 		}
 
   /* var_type declaration (reg variables) cannot be input or output,
diff --git a/vvp/vpi_const.cc b/vvp/vpi_const.cc
index 0773a4377..78202e521 100644
--- a/vvp/vpi_const.cc
+++ b/vvp/vpi_const.cc
@@ -696,16 +696,7 @@ static void real_value(vpiHandle ref, p_vpi_value vp)
       assert((ref->vpi_type->type_code == vpiConstant) ||
              (ref->vpi_type->type_code == vpiParameter));
 
-      switch (vp->format) {
-	  case vpiObjTypeVal:
-	    vp->format = vpiRealVal;
-	  case vpiRealVal:
-	    vp->value.real = rfp->value;
-	    break;
-	  default:
-	    fprintf(stderr, "vvp error: unsupported format %d.\n", vp->format);
-	    assert(0);
-      }
+       vpip_real_get_value(rfp->value, vp);
 }
 
 static const struct __vpirt vpip_real_rt = {
diff --git a/vvp/vthread.cc b/vvp/vthread.cc
index b11a2f034..438a1761c 100644
--- a/vvp/vthread.cc
+++ b/vvp/vthread.cc
@@ -984,7 +984,7 @@ bool of_ASSIGN_V0X1(vthread_t thr, vvp_code_t cp)
       if (off >= (long)sig->size()) return true;
       else if (off < 0 ) {
 	      // We fell off the LSB end.
-	    if ((unsigned)-off > wid ) return true;
+	    if ((unsigned)-off >= wid ) return true;
 	      // Trim the bits before the LSB
 	    wid += off;
 	    bit -= off;
@@ -1021,7 +1021,7 @@ bool of_ASSIGN_V0X1D(vthread_t thr, vvp_code_t cp)
       if (off >= (long)sig->size()) return true;
       else if (off < 0 ) {
 	      // We fell off the LSB end.
-	    if ((unsigned)-off > wid ) return true;
+	    if ((unsigned)-off >= wid ) return true;
 	      // Trim the bits before the LSB
 	    wid += off;
 	    bit -= off;
@@ -1060,7 +1060,7 @@ bool of_ASSIGN_V0X1E(vthread_t thr, vvp_code_t cp)
 	    return true;
       } else if (off < 0 ) {
 	      // We fell off the LSB end.
-	    if ((unsigned)-off > wid ) {
+	    if ((unsigned)-off >= wid ) {
 		  thr->event = 0;
 		  thr->ecount = 0;
 		  return true;