diff --git a/b2g/chrome/content/settings.js b/b2g/chrome/content/settings.js
index d6cb4df10ae..11a37c4c36f 100644
--- a/b2g/chrome/content/settings.js
+++ b/b2g/chrome/content/settings.js
@@ -194,6 +194,24 @@ SettingsListener.observe('devtools.overlay', false, (value) => {
   }
 });
 
+#ifdef MOZ_WIDGET_GONK
+let LogShake;
+SettingsListener.observe('devtools.logshake', false, (value) => {
+  if (value) {
+    if (!LogShake) {
+      let scope = {};
+      Cu.import('resource://gre/modules/LogShake.jsm', scope);
+      LogShake = scope.LogShake;
+    }
+    LogShake.init();
+  } else {
+    if (LogShake) {
+      LogShake.uninit();
+    }
+  }
+});
+#endif
+
 // =================== Device Storage ====================
 SettingsListener.observe('device.storage.writable.name', 'sdcard', function(value) {
   if (Services.prefs.getPrefType('device.storage.writable.name') != Ci.nsIPrefBranch.PREF_STRING) {
diff --git a/b2g/components/LogCapture.jsm b/b2g/components/LogCapture.jsm
new file mode 100644
index 00000000000..adff54c6790
--- /dev/null
+++ b/b2g/components/LogCapture.jsm
@@ -0,0 +1,91 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+/* jshint moz: true */
+/* global Uint8Array, Components, dump */
+
+'use strict';
+
+this.EXPORTED_SYMBOLS = ['LogCapture'];
+
+/**
+ * readLogFile
+ * Read in /dev/log/{{log}} in nonblocking mode, which will return -1 if
+ * reading would block the thread.
+ *
+ * @param log {String} The log from which to read. Must be present in /dev/log
+ * @return {Uint8Array} Raw log data
+ */
+let readLogFile = function(logLocation) {
+  if (!this.ctypes) {
+    // load in everything on first use
+    Components.utils.import('resource://gre/modules/ctypes.jsm', this);
+
+    this.lib = this.ctypes.open(this.ctypes.libraryName('c'));
+
+    this.read = this.lib.declare('read',
+      this.ctypes.default_abi,
+      this.ctypes.int,       // bytes read (out)
+      this.ctypes.int,       // file descriptor (in)
+      this.ctypes.voidptr_t, // buffer to read into (in)
+      this.ctypes.size_t     // size_t size of buffer (in)
+    );
+
+    this.open = this.lib.declare('open',
+      this.ctypes.default_abi,
+      this.ctypes.int,      // file descriptor (returned)
+      this.ctypes.char.ptr, // path
+      this.ctypes.int       // flags
+    );
+
+    this.close = this.lib.declare('close',
+      this.ctypes.default_abi,
+      this.ctypes.int, // error code (returned)
+      this.ctypes.int  // file descriptor
+    );
+  }
+
+  const O_READONLY = 0;
+  const O_NONBLOCK = 1 << 11;
+
+  const BUF_SIZE = 2048;
+
+  let BufType = this.ctypes.ArrayType(this.ctypes.char);
+  let buf = new BufType(BUF_SIZE);
+  let logArray = [];
+
+  let logFd = this.open(logLocation, O_READONLY | O_NONBLOCK);
+  if (logFd === -1) {
+    return null;
+  }
+
+  let readStart = Date.now();
+  let readCount = 0;
+  while (true) {
+    let count = this.read(logFd, buf, BUF_SIZE);
+    readCount += 1;
+
+    if (count <= 0) {
+      // log has return due to being nonblocking or running out of things
+      break;
+    }
+    for(let i = 0; i < count; i++) {
+      logArray.push(buf[i]);
+    }
+  }
+
+  let logTypedArray = new Uint8Array(logArray);
+
+  this.close(logFd);
+
+  return logTypedArray;
+};
+
+let cleanup = function() {
+  this.lib.close();
+  this.read = this.open = this.close = null;
+  this.lib = null;
+  this.ctypes = null;
+};
+
+this.LogCapture = { readLogFile: readLogFile, cleanup: cleanup };
diff --git a/b2g/components/LogParser.jsm b/b2g/components/LogParser.jsm
new file mode 100644
index 00000000000..b3ab436184d
--- /dev/null
+++ b/b2g/components/LogParser.jsm
@@ -0,0 +1,301 @@
+/* jshint esnext: true */
+/* global DataView */
+
+"use strict";
+
+this.EXPORTED_SYMBOLS = ["LogParser"];
+
+/**
+ * Parse an array read from a /dev/log/ file. Format taken from
+ * kernel/drivers/staging/android/logger.h and system/core/logcat/logcat.cpp
+ *
+ * @param array {Uint8Array} Array read from /dev/log/ file
+ * @return {Array} List of log messages
+ */
+function parseLogArray(array) {
+  let data = new DataView(array.buffer);
+  let byteString = String.fromCharCode.apply(null, array);
+
+  let logMessages = [];
+  let pos = 0;
+
+  while (pos < byteString.length) {
+    // Parse a single log entry
+
+    // Track current offset from global position
+    let offset = 0;
+
+    // Length of the entry, discarded
+    let length = data.getUint32(pos + offset, true);
+    offset += 4;
+    // Id of the process which generated the message
+    let processId = data.getUint32(pos + offset, true);
+    offset += 4;
+    // Id of the thread which generated the message
+    let threadId = data.getUint32(pos + offset, true);
+    offset += 4;
+    // Seconds since epoch when this message was logged
+    let seconds = data.getUint32(pos + offset, true);
+    offset += 4;
+    // Nanoseconds since the last second
+    let nanoseconds = data.getUint32(pos + offset, true);
+    offset += 4;
+
+    // Priority in terms of the ANDROID_LOG_* constants (see below)
+    // This is where the length field begins counting
+    let priority = data.getUint8(pos + offset);
+
+    // Reset pos and offset to count from here
+    pos += offset;
+    offset = 0;
+    offset += 1;
+
+    // Read the tag and message, represented as null-terminated c-style strings
+    let tag = "";
+    while (byteString[pos + offset] != "\0") {
+      tag += byteString[pos + offset];
+      offset ++;
+    }
+    offset ++;
+
+    let message = "";
+    // The kernel log driver may have cut off the null byte (logprint.c)
+    while (byteString[pos + offset] != "\0" && offset < length) {
+      message += byteString[pos + offset];
+      offset ++;
+    }
+
+    // Un-skip the missing null terminator
+    if (offset === length) {
+      offset --;
+    }
+
+    offset ++;
+
+    pos += offset;
+
+    // Log messages are occasionally delimited by newlines, but are also
+    // sometimes followed by newlines as well
+    if (message.charAt(message.length - 1) === "\n") {
+      message = message.substring(0, message.length - 1);
+    }
+
+    // Add an aditional time property to mimic the milliseconds since UTC
+    // expected by Date
+    let time = seconds * 1000.0 + nanoseconds/1000000.0;
+
+    // Log messages with interleaved newlines are considered to be separate log
+    // messages by logcat
+    for (let lineMessage of message.split("\n")) {
+      logMessages.push({
+        processId: processId,
+        threadId: threadId,
+        seconds: seconds,
+        nanoseconds: nanoseconds,
+        time: time,
+        priority: priority,
+        tag: tag,
+        message: lineMessage + "\n"
+      });
+    }
+  }
+
+  return logMessages;
+}
+
+/**
+ * Get a thread-time style formatted string from time
+ * @param time {Number} Milliseconds since epoch
+ * @return {String} Formatted time string
+ */
+function getTimeString(time) {
+  let date = new Date(time);
+  function pad(number) {
+    if ( number < 10 ) {
+      return "0" + number;
+    }
+    return number;
+  }
+  return pad( date.getMonth() + 1 ) +
+         "-" + pad( date.getDate() ) +
+         " " + pad( date.getHours() ) +
+         ":" + pad( date.getMinutes() ) +
+         ":" + pad( date.getSeconds() ) +
+         "." + (date.getMilliseconds() / 1000).toFixed(3).slice(2, 5);
+}
+
+/**
+ * Pad a string using spaces on the left
+ * @param str   {String} String to pad
+ * @param width {Number} Desired string length
+ */
+function padLeft(str, width) {
+  while (str.length < width) {
+    str = " " + str;
+  }
+  return str;
+}
+
+/**
+ * Pad a string using spaces on the right
+ * @param str   {String} String to pad
+ * @param width {Number} Desired string length
+ */
+function padRight(str, width) {
+  while (str.length < width) {
+    str = str + " ";
+  }
+  return str;
+}
+
+/** Constant values taken from system/core/liblog */
+const ANDROID_LOG_UNKNOWN = 0;
+const ANDROID_LOG_DEFAULT = 1;
+const ANDROID_LOG_VERBOSE = 2;
+const ANDROID_LOG_DEBUG   = 3;
+const ANDROID_LOG_INFO    = 4;
+const ANDROID_LOG_WARN    = 5;
+const ANDROID_LOG_ERROR   = 6;
+const ANDROID_LOG_FATAL   = 7;
+const ANDROID_LOG_SILENT  = 8;
+
+/**
+ * Map a priority number to its abbreviated string equivalent
+ * @param priorityNumber {Number} Log-provided priority number
+ * @return {String} Priority number's abbreviation
+ */
+function getPriorityString(priorityNumber) {
+  switch (priorityNumber) {
+  case ANDROID_LOG_VERBOSE:
+    return "V";
+  case ANDROID_LOG_DEBUG:
+    return "D";
+  case ANDROID_LOG_INFO:
+    return "I";
+  case ANDROID_LOG_WARN:
+    return "W";
+  case ANDROID_LOG_ERROR:
+    return "E";
+  case ANDROID_LOG_FATAL:
+    return "F";
+  case ANDROID_LOG_SILENT:
+    return "S";
+  default:
+    return "?";
+  }
+}
+
+
+/**
+ * Mimic the logcat "threadtime" format, generating a formatted string from a
+ * log message object.
+ * @param logMessage {Object} A log message from the list returned by parseLogArray
+ * @return {String} threadtime formatted summary of the message
+ */
+function formatLogMessage(logMessage) {
+  // MM-DD HH:MM:SS.ms pid tid priority tag: message
+  // from system/core/liblog/logprint.c:
+  return getTimeString(logMessage.time) +
+         " " + padLeft(""+logMessage.processId, 5) +
+         " " + padLeft(""+logMessage.threadId, 5) +
+         " " + getPriorityString(logMessage.priority) +
+         " " + padRight(logMessage.tag, 8) +
+         ": " + logMessage.message;
+}
+
+/**
+ * Pretty-print an array of bytes read from a log file by parsing then
+ * threadtime formatting its entries.
+ * @param array {Uint8Array} Array of a log file's bytes
+ * @return {String} Pretty-printed log
+ */
+function prettyPrintLogArray(array) {
+  let logMessages = parseLogArray(array);
+  return logMessages.map(formatLogMessage).join("");
+}
+
+/**
+ * Parse an array of bytes as a properties file. The structure of the
+ * properties file is derived from bionic/libc/bionic/system_properties.c
+ * @param array {Uint8Array} Array containing property data
+ * @return {Object} Map from property name to property value, both strings
+ */
+function parsePropertiesArray(array) {
+  let data = new DataView(array.buffer);
+  let byteString = String.fromCharCode.apply(null, array);
+
+  let properties = {};
+
+  let propIndex = 0;
+  let propCount = data.getUint32(0, true);
+
+  // first TOC entry is at 32
+  let tocOffset = 32;
+
+  const PROP_NAME_MAX = 32;
+  const PROP_VALUE_MAX = 92;
+
+  while (propIndex < propCount) {
+    // Retrieve offset from file start
+    let infoOffset = data.getUint32(tocOffset, true) & 0xffffff;
+
+    // Now read the name, integer serial, and value
+    let propName = "";
+    let nameOffset = infoOffset;
+    while (byteString[nameOffset] != "\0" &&
+           (nameOffset - infoOffset) < PROP_NAME_MAX) {
+      propName += byteString[nameOffset];
+      nameOffset ++;
+    }
+
+    infoOffset += PROP_NAME_MAX;
+    // Skip serial number
+    infoOffset += 4;
+
+    let propValue = "";
+    nameOffset = infoOffset;
+    while (byteString[nameOffset] != "\0" &&
+           (nameOffset - infoOffset) < PROP_VALUE_MAX) {
+      propValue += byteString[nameOffset];
+      nameOffset ++;
+    }
+
+    // Move to next table of contents entry
+    tocOffset += 4;
+
+    properties[propName] = propValue;
+    propIndex += 1;
+  }
+
+  return properties;
+}
+
+/**
+ * Pretty-print an array read from the /dev/__properties__ file.
+ * @param array {Uint8Array} File data array
+ * @return {String} Human-readable string of property name: property value
+ */
+function prettyPrintPropertiesArray(array) {
+  let properties = parsePropertiesArray(array);
+  let propertiesString = "";
+  for(let propName in properties) {
+    propertiesString += propName + ": " + properties[propName] + "\n";
+  }
+  return propertiesString;
+}
+
+/**
+ * Pretty-print a normal array. Does nothing.
+ * @param array {Uint8Array} Input array
+ */
+function prettyPrintArray(array) {
+  return array;
+}
+
+this.LogParser = {
+  parseLogArray: parseLogArray,
+  parsePropertiesArray: parsePropertiesArray,
+  prettyPrintArray: prettyPrintArray,
+  prettyPrintLogArray: prettyPrintLogArray,
+  prettyPrintPropertiesArray: prettyPrintPropertiesArray
+};
diff --git a/b2g/components/LogShake.jsm b/b2g/components/LogShake.jsm
new file mode 100644
index 00000000000..a1acffa50fd
--- /dev/null
+++ b/b2g/components/LogShake.jsm
@@ -0,0 +1,301 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * LogShake is a module which listens for log requests sent by Gaia. In
+ * response to a sufficiently large acceleration (a shake), it will save log
+ * files to an arbitrary directory which it will then return on a
+ * 'capture-logs-success' event with detail.logFilenames representing each log
+ * file's filename in the directory. If an error occurs it will instead produce
+ * a 'capture-logs-error' event.
+ */
+
+/* enable Mozilla javascript extensions and global strictness declaration,
+ * disable valid this checking */
+/* jshint moz: true */
+/* jshint -W097 */
+/* jshint -W040 */
+/* global Services, Components, dump, LogCapture, LogParser,
+   OS, Promise, volumeService, XPCOMUtils, SystemAppProxy */
+
+'use strict';
+
+const Cu = Components.utils;
+const Ci = Components.interfaces;
+
+Cu.import('resource://gre/modules/XPCOMUtils.jsm');
+
+XPCOMUtils.defineLazyModuleGetter(this, 'LogCapture', 'resource://gre/modules/LogCapture.jsm');
+XPCOMUtils.defineLazyModuleGetter(this, 'LogParser', 'resource://gre/modules/LogParser.jsm');
+XPCOMUtils.defineLazyModuleGetter(this, 'OS', 'resource://gre/modules/osfile.jsm');
+XPCOMUtils.defineLazyModuleGetter(this, 'Promise', 'resource://gre/modules/Promise.jsm');
+XPCOMUtils.defineLazyModuleGetter(this, 'Services', 'resource://gre/modules/Services.jsm');
+XPCOMUtils.defineLazyModuleGetter(this, 'SystemAppProxy', 'resource://gre/modules/SystemAppProxy.jsm');
+
+XPCOMUtils.defineLazyServiceGetter(this, 'powerManagerService',
+                                   '@mozilla.org/power/powermanagerservice;1',
+                                   'nsIPowerManagerService');
+
+XPCOMUtils.defineLazyServiceGetter(this, 'volumeService',
+                                   '@mozilla.org/telephony/volume-service;1',
+                                   'nsIVolumeService');
+
+this.EXPORTED_SYMBOLS = ['LogShake'];
+
+function debug(msg) {
+  dump('LogShake.jsm: '+msg+'\n');
+}
+
+/**
+ * An empirically determined amount of acceleration corresponding to a
+ * shake
+ */
+const EXCITEMENT_THRESHOLD = 500;
+const DEVICE_MOTION_EVENT = 'devicemotion';
+const SCREEN_CHANGE_EVENT = 'screenchange';
+const CAPTURE_LOGS_ERROR_EVENT = 'capture-logs-error';
+const CAPTURE_LOGS_SUCCESS_EVENT = 'capture-logs-success';
+
+// Map of files which have log-type information to their parsers
+const LOGS_WITH_PARSERS = {
+  '/dev/__properties__': LogParser.prettyPrintPropertiesArray,
+  '/dev/log/main': LogParser.prettyPrintLogArray,
+  '/dev/log/system': LogParser.prettyPrintLogArray,
+  '/dev/log/radio': LogParser.prettyPrintLogArray,
+  '/dev/log/events': LogParser.prettyPrintLogArray,
+  '/proc/cmdline': LogParser.prettyPrintArray,
+  '/proc/kmsg': LogParser.prettyPrintArray,
+  '/proc/meminfo': LogParser.prettyPrintArray,
+  '/proc/uptime': LogParser.prettyPrintArray,
+  '/proc/version': LogParser.prettyPrintArray,
+  '/proc/vmallocinfo': LogParser.prettyPrintArray,
+  '/proc/vmstat': LogParser.prettyPrintArray
+};
+
+let LogShake = {
+  QueryInterface: XPCOMUtils.generateQI([Ci.nsIObserver]),
+  /**
+   * If LogShake is listening for device motion events. Required due to lag
+   * between HAL layer of device motion events and listening for device motion
+   * events.
+   */
+  deviceMotionEnabled: false,
+
+  /**
+   * If a capture has been requested and is waiting for reads/parsing. Used for
+   * debouncing.
+   */
+  captureRequested: false,
+
+  /**
+   * Start existing, observing motion events if the screen is turned on.
+   */
+  init: function() {
+    // TODO: no way of querying screen state from power manager
+    // this.handleScreenChangeEvent({ detail: {
+    //   screenEnabled: powerManagerService.screenEnabled
+    // }});
+
+    // However, the screen is always on when we are being enabled because it is
+    // either due to the phone starting up or a user enabling us directly.
+    this.handleScreenChangeEvent({ detail: {
+      screenEnabled: true
+    }});
+
+    SystemAppProxy.addEventListener(SCREEN_CHANGE_EVENT, this, false);
+
+    Services.obs.addObserver(this, 'xpcom-shutdown', false);
+  },
+
+  /**
+   * Handle an arbitrary event, passing it along to the proper function
+   */
+  handleEvent: function(event) {
+    switch (event.type) {
+    case DEVICE_MOTION_EVENT:
+      if (!this.deviceMotionEnabled) {
+        return;
+      }
+      this.handleDeviceMotionEvent(event);
+      break;
+
+    case SCREEN_CHANGE_EVENT:
+      this.handleScreenChangeEvent(event);
+      break;
+    }
+  },
+
+  /**
+   * Handle an observation from Services.obs
+   */
+  observe: function(subject, topic) {
+    if (topic === 'xpcom-shutdown') {
+      this.uninit();
+    }
+  },
+
+  startDeviceMotionListener: function() {
+    if (!this.deviceMotionEnabled) {
+      SystemAppProxy.addEventListener(DEVICE_MOTION_EVENT, this, false);
+      this.deviceMotionEnabled = true;
+    }
+  },
+
+  stopDeviceMotionListener: function() {
+    SystemAppProxy.removeEventListener(DEVICE_MOTION_EVENT, this, false);
+    this.deviceMotionEnabled = false;
+  },
+
+  /**
+   * Handle a motion event, keeping track of 'excitement', the magnitude
+   * of the device's acceleration.
+   */
+  handleDeviceMotionEvent: function(event) {
+    // There is a lag between disabling the event listener and event arrival
+    // ceasing.
+    if (!this.deviceMotionEnabled) {
+      return;
+    }
+
+    var acc = event.accelerationIncludingGravity;
+
+    var excitement = acc.x * acc.x + acc.y * acc.y + acc.z * acc.z;
+
+    if (excitement > EXCITEMENT_THRESHOLD) {
+      if (!this.captureRequested) {
+        this.captureRequested = true;
+        captureLogs().then(logResults => {
+          // On resolution send the success event to the requester
+          SystemAppProxy._sendCustomEvent(CAPTURE_LOGS_SUCCESS_EVENT, {
+            logFilenames: logResults.logFilenames,
+            logPrefix: logResults.logPrefix
+          });
+          this.captureRequested = false;
+        },
+        error => {
+          // On an error send the error event
+          SystemAppProxy._sendCustomEvent(CAPTURE_LOGS_ERROR_EVENT, {error: error});
+          this.captureRequested = false;
+        });
+      }
+    }
+  },
+
+  handleScreenChangeEvent: function(event) {
+    if (event.detail.screenEnabled) {
+      this.startDeviceMotionListener();
+    } else {
+      this.stopDeviceMotionListener();
+    }
+  },
+
+  /**
+   * Stop logshake, removing all listeners
+   */
+  uninit: function() {
+    this.stopDeviceMotionListener();
+    SystemAppProxy.removeEventListener(SCREEN_CHANGE_EVENT, this, false);
+    Services.obs.removeObserver(this, 'xpcom-shutdown');
+  }
+};
+
+function getLogFilename(logLocation) {
+  // sanitize the log location
+  let logName = logLocation.replace(/\//g, '-');
+  if (logName[0] === '-') {
+    logName = logName.substring(1);
+  }
+  return logName + '.log';
+}
+
+function getSdcardPrefix() {
+  return volumeService.getVolumeByName('sdcard').mountPoint;
+}
+
+function getLogDirectory() {
+  let d = new Date();
+  d = new Date(d.getTime() - d.getTimezoneOffset() * 60000);
+  let timestamp = d.toISOString().slice(0, -5).replace(/[:T]/g, '-');
+  // return directory name of format 'logs/timestamp/'
+  return OS.Path.join('logs', timestamp, '');
+}
+
+/**
+ * Captures and saves the current device logs, returning a promise that will
+ * resolve to an array of log filenames.
+ */
+function captureLogs() {
+  let logArrays = readLogs();
+  return saveLogs(logArrays);
+}
+
+/**
+ * Read in all log files, returning their formatted contents
+ */
+function readLogs() {
+  let logArrays = {};
+  for (let loc in LOGS_WITH_PARSERS) {
+    let logArray = LogCapture.readLogFile(loc);
+    if (!logArray) {
+      continue;
+    }
+    let prettyLogArray = LOGS_WITH_PARSERS[loc](logArray);
+
+    logArrays[loc] = prettyLogArray;
+  }
+  return logArrays;
+}
+
+/**
+ * Save the formatted arrays of log files to an sdcard if available
+ */
+function saveLogs(logArrays) {
+  if (!logArrays || Object.keys(logArrays).length === 0) {
+    return Promise.resolve({
+      logFilenames: [],
+      logPrefix: ''
+    });
+  }
+
+  let sdcardPrefix, dirName;
+  try {
+    sdcardPrefix = getSdcardPrefix();
+    dirName = getLogDirectory();
+  } catch(e) {
+    // Return promise failed with exception e
+    // Handles missing sdcard
+    return Promise.reject(e);
+  }
+
+  debug('making a directory all the way from '+sdcardPrefix+' to '+(sdcardPrefix + '/' + dirName));
+  return OS.File.makeDir(OS.Path.join(sdcardPrefix, dirName), {from: sdcardPrefix})
+    .then(function() {
+    // Now the directory is guaranteed to exist, save the logs
+    let logFilenames = [];
+    let saveRequests = [];
+
+    for (let logLocation in logArrays) {
+      debug('requesting save of ' + logLocation);
+      let logArray = logArrays[logLocation];
+      // The filename represents the relative path within the SD card, not the
+      // absolute path because Gaia will refer to it using the DeviceStorage
+      // API
+      let filename = dirName + getLogFilename(logLocation);
+      logFilenames.push(filename);
+      let saveRequest = OS.File.writeAtomic(OS.Path.join(sdcardPrefix, filename), logArray);
+      saveRequests.push(saveRequest);
+    }
+
+    return Promise.all(saveRequests).then(function() {
+      debug('returning logfilenames: '+logFilenames.toSource());
+      return {
+        logFilenames: logFilenames,
+        logPrefix: dirName
+      };
+    });
+  });
+}
+
+LogShake.init();
+this.LogShake = LogShake;
diff --git a/b2g/components/moz.build b/b2g/components/moz.build
index 856d9d898c4..841e450dee3 100644
--- a/b2g/components/moz.build
+++ b/b2g/components/moz.build
@@ -52,6 +52,9 @@ EXTRA_JS_MODULES += [
     'ContentRequestHelper.jsm',
     'ErrorPage.jsm',
     'FxAccountsMgmtService.jsm',
+    'LogCapture.jsm',
+    'LogParser.jsm',
+    'LogShake.jsm',
     'SignInToWebsite.jsm',
     'SystemAppProxy.jsm',
     'TelURIParser.jsm',
diff --git a/b2g/components/test/unit/data/test_logger_file b/b2g/components/test/unit/data/test_logger_file
new file mode 100644
index 00000000000..b1ed7f10ae8
Binary files /dev/null and b/b2g/components/test/unit/data/test_logger_file differ
diff --git a/b2g/components/test/unit/data/test_properties b/b2g/components/test/unit/data/test_properties
new file mode 100644
index 00000000000..a8254853738
Binary files /dev/null and b/b2g/components/test/unit/data/test_properties differ
diff --git a/b2g/components/test/unit/test_logcapture.js b/b2g/components/test/unit/test_logcapture.js
new file mode 100644
index 00000000000..b1102a8c8f9
--- /dev/null
+++ b/b2g/components/test/unit/test_logcapture.js
@@ -0,0 +1,25 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+
+/**
+ * Test that LogCapture successfully reads from the /dev/log devices, returning
+ * a Uint8Array of some length, including zero. This tests a few standard
+ * log devices
+ */
+function run_test() {
+  Components.utils.import('resource:///modules/LogCapture.jsm');
+
+  function verifyLog(log) {
+    // log exists
+    notEqual(log, null);
+    // log has a length and it is non-negative (is probably array-like)
+    ok(log.length >= 0);
+  }
+
+  let mainLog = LogCapture.readLogFile('/dev/log/main');
+  verifyLog(mainLog);
+
+  let meminfoLog = LogCapture.readLogFile('/proc/meminfo');
+  verifyLog(meminfoLog);
+}
diff --git a/b2g/components/test/unit/test_logparser.js b/b2g/components/test/unit/test_logparser.js
new file mode 100644
index 00000000000..04c39bb9983
--- /dev/null
+++ b/b2g/components/test/unit/test_logparser.js
@@ -0,0 +1,49 @@
+/* jshint moz: true */
+
+const {utils: Cu, classes: Cc, interfaces: Ci} = Components;
+
+function run_test() {
+  Cu.import('resource:///modules/LogParser.jsm');
+
+  let propertiesFile = do_get_file('data/test_properties');
+  let loggerFile = do_get_file('data/test_logger_file');
+
+  let propertiesStream = makeStream(propertiesFile);
+  let loggerStream = makeStream(loggerFile);
+
+  // Initialize arrays to hold the file contents (lengths are hardcoded)
+  let propertiesArray = new Uint8Array(propertiesStream.readByteArray(65536));
+  let loggerArray = new Uint8Array(loggerStream.readByteArray(4037));
+
+  propertiesStream.close();
+  loggerStream.close();
+
+  let properties = LogParser.parsePropertiesArray(propertiesArray);
+  let logMessages = LogParser.parseLogArray(loggerArray);
+
+  // Test arbitrary property entries for correctness
+  equal(properties['ro.boot.console'], 'ttyHSL0');
+  equal(properties['net.tcp.buffersize.lte'],
+        '524288,1048576,2097152,262144,524288,1048576');
+
+  ok(logMessages.length === 58, 'There should be 58 messages in the log');
+
+  let expectedLogEntry = {
+    processId: 271, threadId: 271,
+    seconds: 790796, nanoseconds: 620000001, time: 790796620.000001,
+    priority: 4, tag: 'Vold',
+    message: 'Vold 2.1 (the revenge) firing up\n'
+  };
+
+  deepEqual(expectedLogEntry, logMessages[0]);
+}
+
+function makeStream(file) {
+  var fileStream = Cc['@mozilla.org/network/file-input-stream;1']
+                .createInstance(Ci.nsIFileInputStream);
+  fileStream.init(file, -1, -1, 0);
+  var bis = Cc['@mozilla.org/binaryinputstream;1']
+                .createInstance(Ci.nsIBinaryInputStream);
+  bis.setInputStream(fileStream);
+  return bis;
+}
diff --git a/b2g/components/test/unit/test_logshake.js b/b2g/components/test/unit/test_logshake.js
new file mode 100644
index 00000000000..51727d98d0c
--- /dev/null
+++ b/b2g/components/test/unit/test_logshake.js
@@ -0,0 +1,141 @@
+/**
+ * Test the log capturing capabilities of LogShake.jsm
+ */
+
+/* jshint moz: true */
+/* global Components, LogCapture, LogShake, ok, add_test, run_next_test, dump */
+/* exported run_test */
+
+/* disable use strict warning */
+/* jshint -W097 */
+'use strict';
+
+const Cu = Components.utils;
+
+Cu.import('resource://gre/modules/LogCapture.jsm');
+Cu.import('resource://gre/modules/LogShake.jsm');
+
+// Force logshake to handle a device motion event with given components
+// Does not use SystemAppProxy because event needs special
+// accelerationIncludingGravity property
+function sendDeviceMotionEvent(x, y, z) {
+  let event = {
+    type: 'devicemotion',
+    accelerationIncludingGravity: {
+      x: x,
+      y: y,
+      z: z
+    }
+  };
+  LogShake.handleEvent(event);
+}
+
+// Send a screen change event directly, does not use SystemAppProxy due to race
+// conditions.
+function sendScreenChangeEvent(screenEnabled) {
+  let event = {
+    type: 'screenchange',
+    detail: {
+      screenEnabled: screenEnabled
+    }
+  };
+  LogShake.handleEvent(event);
+}
+
+function debug(msg) {
+  var timestamp = Date.now();
+  dump('LogShake: ' + timestamp + ': ' + msg);
+}
+
+add_test(function test_do_log_capture_after_shaking() {
+  // Enable LogShake
+  LogShake.init();
+
+  let readLocations = [];
+  LogCapture.readLogFile = function(loc) {
+    readLocations.push(loc);
+    return null; // we don't want to provide invalid data to a parser
+  };
+
+  // Fire a devicemotion event that is of shake magnitude
+  sendDeviceMotionEvent(9001, 9001, 9001);
+
+  ok(readLocations.length > 0,
+      'LogShake should attempt to read at least one log');
+
+  LogShake.uninit();
+  run_next_test();
+});
+
+add_test(function test_do_nothing_when_resting() {
+  // Enable LogShake
+  LogShake.init();
+
+  let readLocations = [];
+  LogCapture.readLogFile = function(loc) {
+    readLocations.push(loc);
+    return null; // we don't want to provide invalid data to a parser
+  };
+
+  // Fire a devicemotion event that is relatively tiny
+  sendDeviceMotionEvent(0, 9.8, 9.8);
+
+  ok(readLocations.length === 0,
+      'LogShake should not read any logs');
+
+  debug('test_do_nothing_when_resting: stop');
+  LogShake.uninit();
+  run_next_test();
+});
+
+add_test(function test_do_nothing_when_disabled() {
+  debug('test_do_nothing_when_disabled: start');
+  // Disable LogShake
+  LogShake.uninit();
+
+  let readLocations = [];
+  LogCapture.readLogFile = function(loc) {
+    readLocations.push(loc);
+    return null; // we don't want to provide invalid data to a parser
+  };
+
+  // Fire a devicemotion event that would normally be a shake
+  sendDeviceMotionEvent(0, 9001, 9001);
+
+  ok(readLocations.length === 0,
+      'LogShake should not read any logs');
+
+  run_next_test();
+});
+
+add_test(function test_do_nothing_when_screen_off() {
+  // Enable LogShake
+  LogShake.init();
+
+
+  // Send an event as if the screen has been turned off
+  sendScreenChangeEvent(false);
+
+  let readLocations = [];
+  LogCapture.readLogFile = function(loc) {
+    readLocations.push(loc);
+    return null; // we don't want to provide invalid data to a parser
+  };
+
+  // Fire a devicemotion event that would normally be a shake
+  sendDeviceMotionEvent(0, 9001, 9001);
+
+  ok(readLocations.length === 0,
+      'LogShake should not read any logs');
+
+  // Restore the screen
+  sendScreenChangeEvent(true);
+
+  LogShake.uninit();
+  run_next_test();
+});
+
+function run_test() {
+  debug('Starting');
+  run_next_test();
+}
diff --git a/b2g/components/test/unit/xpcshell.ini b/b2g/components/test/unit/xpcshell.ini
index bf7a26e4961..84626cef801 100644
--- a/b2g/components/test/unit/xpcshell.ini
+++ b/b2g/components/test/unit/xpcshell.ini
@@ -2,6 +2,10 @@
 head =
 tail =
 
+support-files =
+  data/test_logger_file
+  data/test_properties
+
 [test_bug793310.js]
 
 [test_bug832946.js]
@@ -11,4 +15,10 @@ tail =
 head = head_identity.js
 tail =
 
+[test_logcapture.js]
+# only run on b2g builds due to requiring b2g-specific log files to exist
+skip-if = toolkit != "gonk"
 
+[test_logparser.js]
+
+[test_logshake.js]