diff --git a/systrace-legacy.py b/systrace-legacy.py
new file mode 100755
index 0000000..98eeb87
--- /dev/null
+++ b/systrace-legacy.py
@@ -0,0 +1,280 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2011 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Android system-wide tracing utility.
+
+This is a tool for capturing a trace that includes data from both userland and
+the kernel.  It creates an HTML file for visualizing the trace.
+"""
+
+import errno, optparse, os, select, subprocess, sys, time, zlib
+
+# This list is based on the tags in frameworks/native/include/utils/Trace.h.
+trace_tag_bits = {
+  'gfx':      1<<1,
+  'input':    1<<2,
+  'view':     1<<3,
+  'webview':  1<<4,
+  'wm':       1<<5,
+  'am':       1<<6,
+  'sync':     1<<7,
+  'audio':    1<<8,
+  'video':    1<<9,
+  'camera':   1<<10,
+}
+
+flattened_css_file = 'style.css'
+flattened_js_file = 'script.js'
+
+def add_adb_serial(command, serial):
+  if serial != None:
+    command.insert(1, serial)
+    command.insert(1, '-s')
+
+def main():
+  parser = optparse.OptionParser()
+  parser.add_option('-o', dest='output_file', help='write HTML to FILE',
+                    default='trace.html', metavar='FILE')
+  parser.add_option('-t', '--time', dest='trace_time', type='int',
+                    help='trace for N seconds', metavar='N')
+  parser.add_option('-b', '--buf-size', dest='trace_buf_size', type='int',
+                    help='use a trace buffer size of N KB', metavar='N')
+  parser.add_option('-d', '--disk', dest='trace_disk', default=False,
+                    action='store_true', help='trace disk I/O (requires root)')
+  parser.add_option('-f', '--cpu-freq', dest='trace_cpu_freq', default=False,
+                    action='store_true', help='trace CPU frequency changes')
+  parser.add_option('-i', '--cpu-idle', dest='trace_cpu_idle', default=False,
+                    action='store_true', help='trace CPU idle events')
+  parser.add_option('-l', '--cpu-load', dest='trace_cpu_load', default=False,
+                    action='store_true', help='trace CPU load')
+  parser.add_option('-s', '--no-cpu-sched', dest='trace_cpu_sched', default=True,
+                    action='store_false', help='inhibit tracing CPU ' +
+                    'scheduler (allows longer trace times by reducing data ' +
+                    'rate into buffer)')
+  parser.add_option('-u', '--bus-utilization', dest='trace_bus_utilization',
+                    default=False, action='store_true',
+                    help='trace bus utilization (requires root)')
+  parser.add_option('-w', '--workqueue', dest='trace_workqueue', default=False,
+                    action='store_true', help='trace the kernel workqueues ' +
+                    '(requires root)')
+  parser.add_option('--set-tags', dest='set_tags', action='store',
+                    help='set the enabled trace tags and exit; set to a ' +
+                    'comma separated list of: ' +
+                    ', '.join(trace_tag_bits.iterkeys()))
+  parser.add_option('--link-assets', dest='link_assets', default=False,
+                    action='store_true', help='link to original CSS or JS resources '
+                    'instead of embedding them')
+  parser.add_option('--from-file', dest='from_file', action='store',
+                    help='read the trace from a file rather than running a live trace')
+  parser.add_option('--asset-dir', dest='asset_dir', default='trace-viewer',
+                    type='string', help='')
+  parser.add_option('-e', '--serial', dest='device_serial', type='string',
+                    help='adb device serial number')
+  options, args = parser.parse_args()
+
+  if options.set_tags:
+    flags = 0
+    tags = options.set_tags.split(',')
+    for tag in tags:
+      try:
+        flags |= trace_tag_bits[tag]
+      except KeyError:
+        parser.error('unrecognized tag: %s\nknown tags are: %s' %
+                     (tag, ', '.join(trace_tag_bits.iterkeys())))
+    atrace_args = ['adb', 'shell', 'setprop', 'debug.atrace.tags.enableflags', hex(flags)]
+    add_adb_serial(atrace_args, options.device_serial)
+    try:
+      subprocess.check_call(atrace_args)
+    except subprocess.CalledProcessError, e:
+      print >> sys.stderr, 'unable to set tags: %s' % e
+    print '\nSet enabled tags to: %s\n' % ', '.join(tags)
+    print ('You will likely need to restart the Android framework for this to ' +
+          'take effect:\n\n    adb shell stop\n    adb shell ' +
+          'start\n')
+    return
+
+  atrace_args = ['adb', 'shell', 'atrace', '-z']
+  add_adb_serial(atrace_args, options.device_serial)
+
+  if options.trace_disk:
+    atrace_args.append('-d')
+  if options.trace_cpu_freq:
+    atrace_args.append('-f')
+  if options.trace_cpu_idle:
+    atrace_args.append('-i')
+  if options.trace_cpu_load:
+    atrace_args.append('-l')
+  if options.trace_cpu_sched:
+    atrace_args.append('-s')
+  if options.trace_bus_utilization:
+    atrace_args.append('-u')
+  if options.trace_workqueue:
+    atrace_args.append('-w')
+  if options.trace_time is not None:
+    if options.trace_time > 0:
+      atrace_args.extend(['-t', str(options.trace_time)])
+    else:
+      parser.error('the trace time must be a positive number')
+  if options.trace_buf_size is not None:
+    if options.trace_buf_size > 0:
+      atrace_args.extend(['-b', str(options.trace_buf_size)])
+    else:
+      parser.error('the trace buffer size must be a positive number')
+
+  if options.from_file is not None:
+    atrace_args = ['cat', options.from_file]
+
+  script_dir = os.path.dirname(os.path.abspath(sys.argv[0]))
+
+  if options.link_assets:
+    src_dir = os.path.join(script_dir, options.asset_dir, 'src')
+    build_dir = os.path.join(script_dir, options.asset_dir, 'build')
+
+    js_files, js_flattenizer, css_files = get_assets(src_dir, build_dir)
+
+    css = '\n'.join(linked_css_tag % (os.path.join(src_dir, f)) for f in css_files)
+    js = '<script language="javascript">\n%s</script>\n' % js_flattenizer
+    js += '\n'.join(linked_js_tag % (os.path.join(src_dir, f)) for f in js_files)
+  else:
+    css_filename = os.path.join(script_dir, flattened_css_file)
+    js_filename = os.path.join(script_dir, flattened_js_file)
+    css = compiled_css_tag % (open(css_filename).read())
+    js = compiled_js_tag % (open(js_filename).read())
+
+  html_filename = options.output_file
+
+  trace_started = False
+  leftovers = ''
+  adb = subprocess.Popen(atrace_args, stdout=subprocess.PIPE,
+                         stderr=subprocess.PIPE)
+  dec = zlib.decompressobj()
+  while True:
+    ready = select.select([adb.stdout, adb.stderr], [], [adb.stdout, adb.stderr])
+    if adb.stderr in ready[0]:
+      err = os.read(adb.stderr.fileno(), 4096)
+      sys.stderr.write(err)
+      sys.stderr.flush()
+    if adb.stdout in ready[0]:
+      out = leftovers + os.read(adb.stdout.fileno(), 4096)
+      if options.from_file is None:
+        out = out.replace('\r\n', '\n')
+      if out.endswith('\r'):
+        out = out[:-1]
+        leftovers = '\r'
+      else:
+        leftovers = ''
+      if not trace_started:
+        lines = out.splitlines(True)
+        out = ''
+        for i, line in enumerate(lines):
+          if line == 'TRACE:\n':
+            sys.stdout.write("downloading trace...")
+            sys.stdout.flush()
+            out = ''.join(lines[i+1:])
+            html_file = open(html_filename, 'w')
+            html_file.write(html_prefix % (css, js))
+            trace_started = True
+            break
+          elif 'TRACE:'.startswith(line) and i == len(lines) - 1:
+            leftovers = line + leftovers
+          else:
+            sys.stdout.write(line)
+            sys.stdout.flush()
+      if len(out) > 0:
+        out = dec.decompress(out)
+      html_out = out.replace('\n', '\\n\\\n')
+      if len(html_out) > 0:
+        html_file.write(html_out)
+    result = adb.poll()
+    if result is not None:
+      break
+  if result != 0:
+    print >> sys.stderr, 'adb returned error code %d' % result
+  elif trace_started:
+    html_out = dec.flush().replace('\n', '\\n\\\n').replace('\r', '')
+    if len(html_out) > 0:
+      html_file.write(html_out)
+    html_file.write(html_suffix)
+    html_file.close()
+    print " done\n\n    wrote file://%s/%s\n" % (os.getcwd(), options.output_file)
+  else:
+    print >> sys.stderr, ('An error occured while capturing the trace.  Output ' +
+      'file was not written.')
+
+def get_assets(src_dir, build_dir):
+  sys.path.append(build_dir)
+  gen = __import__('generate_standalone_timeline_view', {}, {})
+  parse_deps = __import__('parse_deps', {}, {})
+  filenames = gen._get_input_filenames()
+  load_sequence = parse_deps.calc_load_sequence(filenames)
+
+  js_files = []
+  js_flattenizer = "window.FLATTENED = {};\n"
+  css_files = []
+
+  for module in load_sequence:
+    js_files.append(os.path.relpath(module.filename, src_dir))
+    js_flattenizer += "window.FLATTENED['%s'] = true;\n" % module.name
+    for style_sheet in module.style_sheets:
+      css_files.append(os.path.relpath(style_sheet.filename, src_dir))
+
+  sys.path.pop()
+
+  return (js_files, js_flattenizer, css_files)
+
+html_prefix = """<!DOCTYPE HTML>
+<html>
+<head i18n-values="dir:textdirection;">
+<title>Android System Trace</title>
+%s
+%s
+<script language="javascript">
+document.addEventListener('DOMContentLoaded', function() {
+  if (!linuxPerfData)
+    return;
+
+  var m = new tracing.Model(linuxPerfData);
+  var timelineViewEl = document.querySelector('.view');
+  tracing.ui.decorate(timelineViewEl, tracing.TimelineView);
+  timelineViewEl.model = m;
+  timelineViewEl.tabIndex = 1;
+  timelineViewEl.timeline.focusElement = timelineViewEl;
+});
+</script>
+<style>
+  .view {
+    overflow: hidden;
+    position: absolute;
+    top: 0;
+    bottom: 0;
+    left: 0;
+    right: 0;
+  }
+</style>
+</head>
+<body>
+  <div class="view">
+  </div>
+<!-- BEGIN TRACE -->
+  <script>
+  var linuxPerfData = "\\
+"""
+
+html_suffix = """\\n";
+  </script>
+<!-- END TRACE -->
+</body>
+</html>
+"""
+
+compiled_css_tag = """<style type="text/css">%s</style>"""
+compiled_js_tag = """<script language="javascript">%s</script>"""
+
+linked_css_tag = """<link rel="stylesheet" href="%s"></link>"""
+linked_js_tag = """<script language="javascript" src="%s"></script>"""
+
+if __name__ == '__main__':
+  main()
diff --git a/systrace.py b/systrace.py
index 3b2585e..41d0cba 100755
--- a/systrace.py
+++ b/systrace.py
@@ -15,12 +15,46 @@
 flattened_css_file = 'style.css'
 flattened_js_file = 'script.js'
 
+class OptionParserIgnoreErrors(optparse.OptionParser):
+  def error(self, msg):
+    pass
+
+  def exit(self):
+    pass
+
+  def print_usage(self):
+    pass
+
+  def print_help(self):
+    pass
+
+  def print_version(self):
+    pass
+
+def get_device_sdk_version():
+  getprop_args = ['adb', 'shell', 'getprop', 'ro.build.version.sdk']
+
+  parser = OptionParserIgnoreErrors()
+  parser.add_option('-e', '--serial', dest='device_serial', type='string')
+  options, args = parser.parse_args()
+  if options.device_serial is not None:
+    getprop_args[1:1] = ['-s', options.device_serial]
+
+  version = subprocess.check_output(getprop_args)
+
+  return int(version)
+
 def add_adb_serial(command, serial):
   if serial != None:
     command.insert(1, serial)
     command.insert(1, '-s')
 
 def main():
+  device_sdk_version = get_device_sdk_version()
+  if device_sdk_version < 18:
+    legacy_script = os.path.join(os.path.dirname(sys.argv[0]), 'systrace-legacy.py')
+    os.execv(legacy_script, sys.argv)
+
   usage = "Usage: %prog [options] [category1 [category2 ...]]"
   desc = "Example: %prog -b 32768 -t 15 gfx input view sched freq"
   parser = optparse.OptionParser(usage=usage, description=desc)