diff --git a/delta_performer_unittest.cc b/delta_performer_unittest.cc
index fb9aabc..89999eb 100755
--- a/delta_performer_unittest.cc
+++ b/delta_performer_unittest.cc
@@ -214,7 +214,6 @@
   // Wrapper around close. Returns 0 on success or -errno on error.
   EXPECT_EQ(0, performer.Close());
 
-  CompareFilesByBlock("/tmp/a_ref", "/tmp/b_ref");
   CompareFilesByBlock(old_kernel, new_kernel);
   
   vector<char> updated_kernel_partition;
diff --git a/omaha_request_prep_action.cc b/omaha_request_prep_action.cc
index 25772d0..7163119 100644
--- a/omaha_request_prep_action.cc
+++ b/omaha_request_prep_action.cc
@@ -36,12 +36,14 @@
   const string track(GetLsbValue("CHROMEOS_RELEASE_TRACK", ""));
   const string update_url(GetLsbValue("CHROMEOS_AUSERVER",
                                       UpdateCheckParams::kUpdateUrl));
+  const string board(GetLsbValue("CHROMEOS_RELEASE_BOARD", ""));
 
   UpdateCheckParams out(machine_id,  // machine_id
                         machine_id,  // user_id (use machine_id)
                         UpdateCheckParams::kOsPlatform,
                         UpdateCheckParams::kOsVersion,
                         sp,  // e.g. 0.2.3.3_i686
+                        board,  // e.g. x86-generic
                         UpdateCheckParams::kAppId,
                         version,  // app version (from lsb-release)
                         "en-US",  // lang
diff --git a/omaha_request_prep_action_unittest.cc b/omaha_request_prep_action_unittest.cc
index 01016c3..1397c4d 100644
--- a/omaha_request_prep_action_unittest.cc
+++ b/omaha_request_prep_action_unittest.cc
@@ -111,6 +111,7 @@
   {
     ASSERT_TRUE(WriteFileString(
         kTestDir + "/etc/lsb-release",
+        "CHROMEOS_RELEASE_BOARD=arm-generic\n"
         "CHROMEOS_RELEASE_FOO=bar\n"
         "CHROMEOS_RELEASE_VERSION=0.2.2.3\n"
         "CHROMEOS_RELEASE_TRACK=footrack"));
@@ -121,6 +122,7 @@
     EXPECT_TRUE(IsValidGuid(out.user_id)) << "id: " << out.user_id;
     EXPECT_EQ("Chrome OS", out.os_platform);
     EXPECT_EQ(string("0.2.2.3_") + GetMachineType(), out.os_sp);
+    EXPECT_EQ("arm-generic", out.os_board);
     EXPECT_EQ("{87efface-864d-49a5-9bb3-4b050a7c227a}", out.app_id);
     EXPECT_EQ("0.2.2.3", out.app_version);
     EXPECT_EQ("en-US", out.app_lang);
diff --git a/update_check_action.cc b/update_check_action.cc
index 98ff3dc..fa8d697 100644
--- a/update_check_action.cc
+++ b/update_check_action.cc
@@ -74,7 +74,8 @@
       "    <o:app appid=\"" + XmlEncode(params.app_id) + "\" version=\"" +
       XmlEncode(params.app_version) + "\" "
       "lang=\"" + XmlEncode(params.app_lang) + "\" track=\"" +
-      XmlEncode(params.app_track) + "\">\n"
+      XmlEncode(params.app_track) + "\" board=\"" +
+      XmlEncode(params.os_board) + "\">\n"
       "        <o:ping active=\"0\"></o:ping>\n"
       "        <o:updatecheck></o:updatecheck>\n"
       "    </o:app>\n"
diff --git a/update_check_action.h b/update_check_action.h
index 831039d..4e759bd 100644
--- a/update_check_action.h
+++ b/update_check_action.h
@@ -36,6 +36,7 @@
                     const std::string& in_os_platform,
                     const std::string& in_os_version,
                     const std::string& in_os_sp,
+                    const std::string& in_os_board,
                     const std::string& in_app_id,
                     const std::string& in_app_version,
                     const std::string& in_app_lang,
@@ -46,6 +47,7 @@
         os_platform(in_os_platform),
         os_version(in_os_version),
         os_sp(in_os_sp),
+        os_board(in_os_board),
         app_id(in_app_id),
         app_version(in_app_version),
         app_lang(in_app_lang),
@@ -57,6 +59,7 @@
   std::string os_platform;
   std::string os_version;
   std::string os_sp;
+  std::string os_board;
   std::string app_id;
   std::string app_version;
   std::string app_lang;
diff --git a/update_check_action_unittest.cc b/update_check_action_unittest.cc
index c730b40..e2e7410 100644
--- a/update_check_action_unittest.cc
+++ b/update_check_action_unittest.cc
@@ -159,6 +159,7 @@
                            UpdateCheckParams::kOsPlatform,
                            UpdateCheckParams::kOsVersion,
                            "",  // os_sp
+                           "x86-generic",
                            UpdateCheckParams::kAppId,
                            "0.1.0.0",
                            "en-US",
@@ -180,6 +181,7 @@
                            UpdateCheckParams::kOsPlatform,
                            UpdateCheckParams::kOsVersion,
                            "service_pack",
+                           "arm-generic",
                            UpdateCheckParams::kAppId,
                            "0.1.0.0",
                            "en-US",
@@ -215,6 +217,7 @@
                            UpdateCheckParams::kOsPlatform,
                            UpdateCheckParams::kOsVersion,
                            "",  // os_sp
+                           "",  // os_board
                            UpdateCheckParams::kAppId,
                            "0.1.0.0",
                            "en-US",
@@ -248,6 +251,7 @@
                            UpdateCheckParams::kOsPlatform,
                            UpdateCheckParams::kOsVersion,
                            "service_pack",
+                           "x86-generic",
                            UpdateCheckParams::kAppId,
                            "0.1.0.0",
                            "en-US",
@@ -269,6 +273,7 @@
                            UpdateCheckParams::kOsPlatform,
                            UpdateCheckParams::kOsVersion,
                            "service_pack",
+                           "x86-generic",
                            UpdateCheckParams::kAppId,
                            "0.1.0.0",
                            "en-US",
@@ -293,6 +298,7 @@
                            UpdateCheckParams::kOsPlatform,
                            UpdateCheckParams::kOsVersion,
                            "service_pack",
+                           "x86-generic",
                            UpdateCheckParams::kAppId,
                            "0.1.0.0",
                            "en-US",
@@ -317,6 +323,7 @@
                            UpdateCheckParams::kOsPlatform,
                            UpdateCheckParams::kOsVersion,
                            "service_pack",
+                           "x86-generic",
                            UpdateCheckParams::kAppId,
                            "0.1.0.0",
                            "en-US",
@@ -341,6 +348,7 @@
                            UpdateCheckParams::kOsPlatform,
                            UpdateCheckParams::kOsVersion,
                            "service_pack",
+                           "x86-generic",
                            UpdateCheckParams::kAppId,
                            "0.1.0.0",
                            "en-US",
@@ -400,6 +408,7 @@
                            UpdateCheckParams::kOsPlatform,
                            UpdateCheckParams::kOsVersion,
                            "",  // os_sp
+                           "",  // os_board
                            UpdateCheckParams::kAppId,
                            "0.1.0.0",
                            "en-US",
@@ -440,6 +449,7 @@
                            UpdateCheckParams::kOsPlatform,
                            UpdateCheckParams::kOsVersion,
                            "testtheservice_pack>",
+                           "x86 generic",
                            UpdateCheckParams::kAppId,
                            "0.1.0.0",
                            "en-US",
@@ -460,6 +470,7 @@
   EXPECT_EQ(post_str.find("testtheuser_id&lt;"), string::npos);
   EXPECT_NE(post_str.find("testtheservice_pack&gt;"), string::npos);
   EXPECT_EQ(post_str.find("testtheservice_pack>"), string::npos);
+  EXPECT_NE(post_str.find("x86 generic"), string::npos);
 }
 
 TEST(UpdateCheckActionTest, XmlDecodeTest) {
@@ -468,6 +479,7 @@
                            UpdateCheckParams::kOsPlatform,
                            UpdateCheckParams::kOsVersion,
                            "service_pack",
+                           "x86-generic",
                            UpdateCheckParams::kAppId,
                            "0.1.0.0",
                            "en-US",
@@ -498,6 +510,7 @@
                            UpdateCheckParams::kOsPlatform,
                            UpdateCheckParams::kOsVersion,
                            "service_pack",
+                           "the_board",
                            UpdateCheckParams::kAppId,
                            "0.1.0.0",
                            "en-US",