diff --git a/debugger/assets/styles/app.css b/debugger/assets/styles/app.css
index 14d7fca14..0cd1bc64e 100644
--- a/debugger/assets/styles/app.css
+++ b/debugger/assets/styles/app.css
@@ -265,6 +265,9 @@ body {
   padding-left: 6px;
   color: #aaa;
 }
+.debugger-fnview-line-highlight-bg {
+  background-color: red;
+}
 .debugger-fnview-graphview {
   order: 2;
   flex: 0 0 auto;
diff --git a/debugger/assets/ui/code/code-tab.html b/debugger/assets/ui/code/code-tab.html
index ea43d5694..500d476ba 100644
--- a/debugger/assets/ui/code/code-tab.html
+++ b/debugger/assets/ui/code/code-tab.html
@@ -1,6 +1,21 @@
 <div class="debugger-main" ng-controller="CodeTabController">
   <div class="debugger-header">
-    debug header/toolbar/etc
+    <div class="btn-group btn-group-sm">
+      <button type="button" class="btn btn-success" ng-click="app.session.continueExecution()" ng-disabled="!app.session.dataSource || !app.session.paused">
+        <span class="glyphicon glyphicon-play"></span>
+      </button>
+      <button type="button" class="btn btn-danger" ng-click="app.session.breakExecution()" ng-disabled="!app.session.dataSource || app.session.paused">
+        <span class="glyphicon glyphicon-pause"></span>
+      </button>
+    </div>
+    <div class="btn-group btn-group-sm">
+      <button type="button" class="btn btn-default" ng-click="showLocation()" ng-disabled="!app.session.dataSource || !app.session.paused">
+        <span class="glyphicon glyphicon glyphicon-arrow-right"></span>
+      </button>
+      <button type="button" class="btn btn-default" ng-click="app.session.stepNext()" ng-disabled="!app.session.dataSource || !app.session.paused">
+        <span class="glyphicon glyphicon-step-forward"></span>
+      </button>
+    </div>
   </div>
   <div class="debugger-body">
     <div class="debugger-fnlist">
@@ -18,7 +33,7 @@
         <div class="debugger-fnlist-list">
           <table class="table table-hover">
             <tr ng-repeat="fn in functionList | filter:functionFilter | orderBy:'address'">
-              <td><a ui-sref="session.code.function({module: selectedModule.name, function: (fn.address | hex32)})">{{fn.name}}</a></td>
+              <td><a ui-sref="session.code.function({function: (fn.address | hex32)})">{{fn.name}}</a></td>
             </tr>
           </table>
         </div>
diff --git a/debugger/assets/ui/code/code-tab.js b/debugger/assets/ui/code/code-tab.js
index 5e746e5be..08bc3b374 100644
--- a/debugger/assets/ui/code/code-tab.js
+++ b/debugger/assets/ui/code/code-tab.js
@@ -61,6 +61,10 @@ module.controller('CodeTabController', function(
     });
   };
 
+  $scope.showLocation = function() {
+    //
+  };
+
   if (app.session.dataSource) {
     refresh();
   }
diff --git a/debugger/assets/ui/code/function-view.js b/debugger/assets/ui/code/function-view.js
index 284066bc2..1b848b388 100644
--- a/debugger/assets/ui/code/function-view.js
+++ b/debugger/assets/ui/code/function-view.js
@@ -16,8 +16,9 @@ var module = angular.module('xe.ui.code.functionView', [
 
 
 module.controller('FunctionViewController', function(
-    $rootScope, $scope, app, log, Breakpoint) {
+    $rootScope, $scope, $location, app, log, Breakpoint) {
   $scope.codeType = 'source';
+  $scope.highlightInfo = null;
 
   function refresh() {
     if (!app.session || !app.session.dataSource) {
@@ -36,6 +37,46 @@ module.controller('FunctionViewController', function(
   $rootScope.$on('refresh', refresh);
   $scope.$watch('functionAddress', refresh);
 
+  function updateHighlight(address) {
+    if (!$scope.sourceLines || $scope.codeType != 'source') {
+      return;
+    }
+    if ($scope.highlightInfo) {
+      if ($scope.highlightInfo.address == address) {
+        return;
+      }
+      var oldLine = $scope.highlightInfo.line;
+      if ($scope.highlightInfo.widget) {
+        $scope.highlightInfo.widget.clear();
+      }
+      $scope.highlightInfo = null;
+      updateLine(oldLine);
+    }
+    // TODO(benvanik): a better mapping.
+    var line = -1;
+    for (var n = 0; n < $scope.sourceLines.length; n++) {
+      var sourceLine = $scope.sourceLines[n];
+      if (sourceLine[0] == 'i' &&
+          sourceLine[1] == address) {
+        line = n;
+        break;
+      }
+    }
+    if (line != -1) {
+      $scope.highlightInfo = {
+        address: address,
+        line: line,
+        widget: null
+      };
+      updateLine(line);
+    }
+  };
+  $scope.$watch(function() {
+    return $location.search();
+  }, function(search) {
+    updateHighlight(parseInt(search.a, 16));
+  });
+
   var textArea = document.querySelector('.debugger-fnview-textarea');
   $scope.codeMirror = CodeMirror.fromTextArea(textArea, {
     mode: 'javascript',
@@ -94,7 +135,7 @@ module.controller('FunctionViewController', function(
         el.innerText = hex32(line[2]);
         cm.setGutterMarker(n, 'debugger-fnview-gutter-code', el);
 
-        updateLineIcon(n, line);
+        updateLine(n);
       }
     }
   };
@@ -140,7 +181,8 @@ module.controller('FunctionViewController', function(
   };
   $scope.$watch('codeType', updateCode);
 
-  function updateLineIcon(line, sourceLine) {
+  function updateLine(line) {
+    var sourceLine = $scope.sourceLines[line];
     var cm = $scope.codeMirror;
     if (sourceLine[0] != 'i') {
       return;
@@ -160,6 +202,26 @@ module.controller('FunctionViewController', function(
       el = null;
     }
     cm.setGutterMarker(line, 'debugger-fnview-gutter-icon', el);
+
+    var highlightInfo = $scope.highlightInfo;
+    if (highlightInfo && highlightInfo.line == line) {
+      /*
+      if (!highlightInfo.widget) {
+        el = document.createElement('div');
+        el.style.width = '100%';
+        el.style.height = '20px';
+        el.style.backgroundColor = 'red';
+        el.innerHTML = 'hi!';
+        highlightInfo.widget = cm.addLineWidget(line, el, {
+          coverGutter: false
+        });
+        cm.scrollIntoView(line, 50);
+      }
+      */
+      cm.addLineClass(line, 'background', 'debugger-fnview-line-highlight-bg');
+    } else {
+      cm.removeLineClass(line, 'background');
+    }
   };
 
   function toggleBreakpoint(line, sourceLine, shiftKey) {
@@ -174,10 +236,11 @@ module.controller('FunctionViewController', function(
       }
     } else {
       // New breakpoint needed.
-      breakpoint = app.session.addCodeBreakpoint(address);
+      breakpoint = app.session.addCodeBreakpoint(
+          $scope.functionAddress, address);
     }
 
-    updateLineIcon(line, sourceLine);
+    updateLine(line);
   };
 
   $scope.codeMirror.on('gutterClick', function(
diff --git a/debugger/src/datasources.js b/debugger/src/datasources.js
index 3119f0514..79296ee90 100644
--- a/debugger/src/datasources.js
+++ b/debugger/src/datasources.js
@@ -25,6 +25,7 @@ module.service('Breakpoint', function() {
   var Breakpoint = function(opt_id) {
     this.id = opt_id || uuid4();
     this.type = Breakpoint.Type.TEMP;
+    this.fnAddress = 0;
     this.address = 0;
     this.enabled = true;
   };
@@ -35,6 +36,7 @@ module.service('Breakpoint', function() {
   Breakpoint.fromJSON = function(json) {
     var breakpoint = new Breakpoint(json.id);
     breakpoint.type = json.type;
+    breakpoint.fnAddress = json.fnAddress;
     breakpoint.address = json.address;
     breakpoint.enabled = json.enabled;
     return breakpoint;
@@ -43,6 +45,7 @@ module.service('Breakpoint', function() {
     return {
       'id': this.id,
       'type': this.type,
+      'fnAddress': this.fnAddress,
       'address': this.address,
       'enabled': this.enabled
     };
@@ -52,8 +55,9 @@ module.service('Breakpoint', function() {
 
 
 module.service('DataSource', function($q) {
-  var DataSource = function(source) {
+  var DataSource = function(source, delegate) {
     this.source = source;
+    this.delegate = delegate;
     this.online = false;
     this.status = 'disconnected';
   };
@@ -129,12 +133,31 @@ module.service('DataSource', function($q) {
     });
   };
 
+  DataSource.prototype.continueExecution = function() {
+    return this.issue({
+      command: 'cpu.continue'
+    });
+  };
+
+  DataSource.prototype.breakExecution = function() {
+    return this.issue({
+      command: 'cpu.break'
+    });
+  };
+
+  DataSource.prototype.stepNext = function() {
+    return this.issue({
+      command: 'cpu.step'
+    });
+  };
+
   return DataSource;
 });
 
-module.service('RemoteDataSource', function($q, log, DataSource) {
-  var RemoteDataSource = function(url) {
-    DataSource.call(this, url);
+module.service('RemoteDataSource', function(
+    $rootScope, $q, log, DataSource) {
+  var RemoteDataSource = function(url, delegate) {
+    DataSource.call(this, url, delegate);
     this.url = url;
     this.socket = null;
     this.nextRequestId_ = 1;
@@ -152,22 +175,26 @@ module.service('RemoteDataSource', function($q, log, DataSource) {
 
     this.socket = new WebSocket(url, []);
     this.socket.onopen = (function() {
-      // TODO(benvanik): handshake
+      $rootScope.$apply((function() {
+        // TODO(benvanik): handshake
 
-      this.online = true;
-      this.status = 'connected';
-      d.resolve();
+        this.online = true;
+        this.status = 'connected';
+        d.resolve();
+      }).bind(this));
     }).bind(this);
 
     this.socket.onclose = (function(e) {
-      this.online = false;
-      if (this.status == 'connecting') {
-        this.status = 'disconnected';
-        d.reject(e.code + ' ' + e.reason);
-      } else {
-        this.status = 'disconnected';
-        log.info('Disconnected');
-      }
+      $rootScope.$apply((function() {
+        this.online = false;
+        if (this.status == 'connecting') {
+          this.status = 'disconnected';
+          d.reject(e.code + ' ' + e.reason);
+        } else {
+          this.status = 'disconnected';
+          log.info('Disconnected');
+        }
+      }).bind(this));
     }).bind(this);
 
     this.socket.onerror = (function(e) {
@@ -175,27 +202,42 @@ module.service('RemoteDataSource', function($q, log, DataSource) {
     }).bind(this);
 
     this.socket.onmessage = (function(e) {
-      console.log('message', e.data);
-      var json = JSON.parse(e.data);
-      if (json.requestId) {
-        // Response to a previous request.
-        var request = this.pendingRequests_[json.requestId];
-        if (request) {
-          delete this.pendingRequests_[json.requestId];
-          if (json.status) {
-            request.deferred.resolve(json.result);
-          } else {
-            request.deferred.reject(json.result);
-          }
-        }
-      } else {
-        // Notification.
-      }
+      $rootScope.$apply((function() {
+        this.socketMessage(e);
+      }).bind(this));
     }).bind(this);
 
     return d.promise;
   };
 
+  RemoteDataSource.prototype.socketMessage = function(e) {
+    console.log('message', e.data);
+    var json = JSON.parse(e.data);
+    if (json.requestId) {
+      // Response to a previous request.
+      var request = this.pendingRequests_[json.requestId];
+      if (request) {
+        delete this.pendingRequests_[json.requestId];
+        if (json.status) {
+          request.deferred.resolve(json.result);
+        } else {
+          request.deferred.reject(json.result);
+        }
+      }
+    } else {
+      // Notification.
+      switch (json.type) {
+      case 'breakpoint':
+        this.delegate.onBreakpointHit(
+            json.breakpointId, json.threadId);
+        break;
+      default:
+        log.error('Unknown notification type: ' + json.type);
+        break;
+      }
+    }
+  };
+
   RemoteDataSource.prototype.dispose = function() {
     this.pendingRequests_ = {};
     this.online = false;
@@ -221,8 +263,8 @@ module.service('RemoteDataSource', function($q, log, DataSource) {
 
 
 module.service('FileDataSource', function($q, DataSource) {
-  var FileDataSource = function(file) {
-    DataSource.call(this, file.name);
+  var FileDataSource = function(file, delegate) {
+    DataSource.call(this, file.name, delegate);
     this.file = file;
   };
   inherits(FileDataSource, DataSource);
diff --git a/debugger/src/router.js b/debugger/src/router.js
index c47405504..e5427ab3b 100644
--- a/debugger/src/router.js
+++ b/debugger/src/router.js
@@ -98,13 +98,11 @@ module.config(function($stateProvider, $urlRouterProvider) {
     onExit: function() {}
   });
   $stateProvider.state('session.code.function', {
-    url: '/:module/:function',
+    url: '/:function?a',
     templateUrl: 'assets/ui/code/function-view.html',
     controller: function($scope, $stateParams) {
-      $scope.moduleName = $stateParams.module;
       $scope.functionAddress = parseInt($stateParams.function, 16);
-      $scope.$emit('xxx');
-      $scope.$broadcast('yyy');
+      $scope.highlightAddress = parseInt($stateParams.a, 16);
     },
     onEnter: function() {},
     onExit: function() {}
diff --git a/debugger/src/session.js b/debugger/src/session.js
index ed92fdf00..3a73c56b2 100644
--- a/debugger/src/session.js
+++ b/debugger/src/session.js
@@ -13,15 +13,18 @@ var module = angular.module('xe.session', []);
 
 
 module.service('Session', function(
-    $rootScope, $q, $http, log,
+    $rootScope, $q, $http, $state, log,
     Breakpoint, FileDataSource, RemoteDataSource) {
   var Session = function(id, opt_dataSource) {
     this.id = id;
 
     this.breakpoints = {};
+    this.breakpointsById = {};
 
     this.dataSource = opt_dataSource || null;
 
+    this.paused = false;
+
     this.loadState();
   };
 
@@ -31,7 +34,11 @@ module.service('Session', function(
   };
 
   Session.prototype.loadState = function() {
-    var json = JSON.parse(window.localStorage[this.id]);
+    var raw = window.localStorage[this.id];
+    if (!raw) {
+      return;
+    }
+    var json = JSON.parse(raw);
     if (!json) {
       return;
     }
@@ -40,8 +47,9 @@ module.service('Session', function(
     this.breakpoints = {};
     for (var n = 0; n < breakpointList.length; n++) {
       var breakpointJson = breakpointList[n];
-      this.breakpoints[breakpointJson.address] =
-          Breakpoint.fromJSON(breakpointJson);
+      var breakpoint = Breakpoint.fromJSON(breakpointJson);
+      this.breakpoints[breakpointJson.address] = breakpoint;
+      this.breakpointsById[breakpoint.id] = breakpoint;
     }
   };
 
@@ -50,8 +58,8 @@ module.service('Session', function(
       id: this.id,
       breakpoints: []
     };
-    for (var key in this.breakpoints) {
-      var breakpoint = this.breakpoints[key];
+    for (var key in this.breakpointsById) {
+      var breakpoint = this.breakpointsById[key];
       if (breakpoint.type != Breakpoint.TEMP) {
         json.breakpoints.push(breakpoint.toJSON());
       }
@@ -97,7 +105,7 @@ module.service('Session', function(
 
     var d = $q.defer();
 
-    var dataSource = new RemoteDataSource(url);
+    var dataSource = new RemoteDataSource(url, this);
     var p = dataSource.open();
     p.then((function() {
       log.info('Connected!');
@@ -167,6 +175,7 @@ module.service('Session', function(
 
   Session.prototype.addBreakpoint = function(breakpoint) {
     this.breakpoints[breakpoint.address] = breakpoint;
+    this.breakpointsById[breakpoint.id] = breakpoint;
     if (this.dataSource) {
       this.dataSource.addBreakpoint(breakpoint);
     }
@@ -174,17 +183,19 @@ module.service('Session', function(
     return breakpoint;
   };
 
-  Session.prototype.addTempBreakpoint = function(address) {
+  Session.prototype.addTempBreakpoint = function(fnAddress, address) {
     var breakpoint = new Breakpoint();
     breakpoint.type = Breakpoint.Type.TEMP;
+    breakpoint.fnAddress = fnAddress;
     breakpoint.address = address;
     breakpoint.enabled = true;
     return this.addBreakpoint(breakpoint);
   };
 
-  Session.prototype.addCodeBreakpoint = function(address) {
+  Session.prototype.addCodeBreakpoint = function(fnAddress, address) {
     var breakpoint = new Breakpoint();
     breakpoint.type = Breakpoint.Type.CODE;
+    breakpoint.fnAddress = fnAddress;
     breakpoint.address = address;
     breakpoint.enabled = true;
     return this.addBreakpoint(breakpoint);
@@ -192,6 +203,7 @@ module.service('Session', function(
 
   Session.prototype.removeBreakpoint = function(breakpoint) {
     delete this.breakpoints[breakpoint.address];
+    delete this.breakpointsById[breakpoint.id];
     if (this.dataSource) {
       this.dataSource.removeBreakpoint(breakpoint.id);
     }
@@ -211,5 +223,60 @@ module.service('Session', function(
     this.saveState();
   };
 
+  Session.prototype.onBreakpointHit = function(breakpointId, threadId) {
+    var breakpoint = this.breakpointsById[breakpointId];
+    var thread = null; // TODO
+    if (!breakpoint) {
+      log.error('Breakpoint hit but not found');
+      return;
+    }
+
+    // Now paused!
+    this.paused = true;
+
+    $state.go('session.code.function', {
+      'function': breakpoint.fnAddress.toString(16).toUpperCase(),
+      'a': breakpoint.address.toString(16).toUpperCase()
+    }, {
+      notify: false,
+      reloadOnSearch: false
+    });
+
+    //
+    log.info('breakpoint!!');
+  };
+
+  Session.prototype.continueExecution = function() {
+    if (!this.dataSource) {
+      return;
+    }
+    this.paused = false;
+    this.dataSource.continueExecution().then(function() {
+    }, function(e) {
+      log.error('Unable to continue: ' + e);
+    });
+  };
+
+  Session.prototype.breakExecution = function() {
+    if (!this.dataSource) {
+      return;
+    }
+    this.dataSource.breakExecution().then(function() {
+    }, function(e) {
+      log.error('Unable to break: ' + e);
+    });
+  };
+
+  Session.prototype.stepNext = function() {
+    if (!this.dataSource) {
+      return;
+    }
+    this.paused = false;
+    this.dataSource.breakExecution().then(function() {
+    }, function(e) {
+      log.error('Unable to step: ' + e);
+    });
+  };
+
   return Session;
 });