diff --git a/minui/events.cpp b/minui/events.cpp
index a6b9671..e6e7bd2 100644
--- a/minui/events.cpp
+++ b/minui/events.cpp
@@ -204,7 +204,7 @@
     return 0;
 }
 
-void ev_iterate_available_keys(std::function<void(int)> f) {
+void ev_iterate_available_keys(const std::function<void(int)>& f) {
     // Use unsigned long to match ioctl's parameter type.
     unsigned long ev_bits[BITS_TO_LONGS(EV_MAX)]; // NOLINT
     unsigned long key_bits[BITS_TO_LONGS(KEY_MAX)]; // NOLINT
diff --git a/minui/minui.h b/minui/minui.h
index e3bc005..d572205 100644
--- a/minui/minui.h
+++ b/minui/minui.h
@@ -67,7 +67,7 @@
 int ev_init(ev_callback input_cb, void* data);
 void ev_exit();
 int ev_add_fd(int fd, ev_callback cb, void* data);
-void ev_iterate_available_keys(std::function<void(int)> f);
+void ev_iterate_available_keys(const std::function<void(int)>& f);
 int ev_sync_key_state(ev_set_key_callback set_key_cb, void* data);
 
 // 'timeout' has the same semantics as poll(2).
@@ -111,8 +111,8 @@
 // given locale.  The image is expected to be a composite of multiple
 // translations of the same text, with special added rows that encode
 // the subimages' size and intended locale in the pixel data.  See
-// development/tools/recovery_l10n for an app that will generate these
-// specialized images from Android resources.
+// bootable/recovery/tools/recovery_l10n for an app that will generate
+// these specialized images from Android resources.
 int res_create_localized_alpha_surface(const char* name, const char* locale,
                                        GRSurface** pSurface);
 
diff --git a/otafault/ota_io.cpp b/otafault/ota_io.cpp
index dd805e5..cb37d51 100644
--- a/otafault/ota_io.cpp
+++ b/otafault/ota_io.cpp
@@ -31,7 +31,7 @@
 static std::string fsync_fault_file_name = "";
 bool have_eio_error = false;
 
-static bool get_hit_file(const char* cached_path, std::string ffn) {
+static bool get_hit_file(const char* cached_path, const std::string& ffn) {
     return should_hit_cache()
         ? !strncmp(cached_path, OTAIO_CACHE_FNAME, strlen(cached_path))
         : !strncmp(cached_path, ffn.c_str(), strlen(cached_path));
diff --git a/recovery-refresh.cpp b/recovery-refresh.cpp
index 333367e..b75c915 100644
--- a/recovery-refresh.cpp
+++ b/recovery-refresh.cpp
@@ -76,7 +76,7 @@
     }
 
     std::string name(filename);
-    size_t dot = name.find_last_of(".");
+    size_t dot = name.find_last_of('.');
     std::string sub = name.substr(0, dot);
 
     if (!strstr(LAST_KMSG_FILE, sub.c_str()) &&
diff --git a/recovery.cpp b/recovery.cpp
index b4dc41b..28dd212 100644
--- a/recovery.cpp
+++ b/recovery.cpp
@@ -1274,7 +1274,7 @@
     }
 
     std::string name(filename);
-    size_t dot = name.find_last_of(".");
+    size_t dot = name.find_last_of('.');
     std::string sub = name.substr(0, dot);
 
     if (!strstr(LAST_KMSG_FILE, sub.c_str()) &&
diff --git a/res-hdpi/images/erasing_text.png b/res-hdpi/images/erasing_text.png
index 774244c..2186c19 100644
--- a/res-hdpi/images/erasing_text.png
+++ b/res-hdpi/images/erasing_text.png
Binary files differ
diff --git a/res-hdpi/images/error_text.png b/res-hdpi/images/error_text.png
index 64a57ec..9700f45 100644
--- a/res-hdpi/images/error_text.png
+++ b/res-hdpi/images/error_text.png
Binary files differ
diff --git a/res-hdpi/images/installing_security_text.png b/res-hdpi/images/installing_security_text.png
new file mode 100644
index 0000000..0f60595
--- /dev/null
+++ b/res-hdpi/images/installing_security_text.png
Binary files differ
diff --git a/res-hdpi/images/installing_text.png b/res-hdpi/images/installing_text.png
index 33b54f1..ec8b875 100644
--- a/res-hdpi/images/installing_text.png
+++ b/res-hdpi/images/installing_text.png
Binary files differ
diff --git a/res-hdpi/images/no_command_text.png b/res-hdpi/images/no_command_text.png
index 9927ecb..3eddcbb 100644
--- a/res-hdpi/images/no_command_text.png
+++ b/res-hdpi/images/no_command_text.png
Binary files differ
diff --git a/res-mdpi/images/erasing_text.png b/res-mdpi/images/erasing_text.png
index fd86c3f..b0dd3c6 100644
--- a/res-mdpi/images/erasing_text.png
+++ b/res-mdpi/images/erasing_text.png
Binary files differ
diff --git a/res-mdpi/images/error_text.png b/res-mdpi/images/error_text.png
index f1b44c9..6a47a59 100644
--- a/res-mdpi/images/error_text.png
+++ b/res-mdpi/images/error_text.png
Binary files differ
diff --git a/res-mdpi/images/installing_security_text.png b/res-mdpi/images/installing_security_text.png
new file mode 100644
index 0000000..1499398
--- /dev/null
+++ b/res-mdpi/images/installing_security_text.png
Binary files differ
diff --git a/res-mdpi/images/installing_text.png b/res-mdpi/images/installing_text.png
index 064b2a3..01e9bfe 100644
--- a/res-mdpi/images/installing_text.png
+++ b/res-mdpi/images/installing_text.png
Binary files differ
diff --git a/res-mdpi/images/no_command_text.png b/res-mdpi/images/no_command_text.png
index 1f29b89..d340df5 100644
--- a/res-mdpi/images/no_command_text.png
+++ b/res-mdpi/images/no_command_text.png
Binary files differ
diff --git a/res-xhdpi/images/erasing_text.png b/res-xhdpi/images/erasing_text.png
index f88e0e6..2f8b469 100644
--- a/res-xhdpi/images/erasing_text.png
+++ b/res-xhdpi/images/erasing_text.png
Binary files differ
diff --git a/res-xhdpi/images/error_text.png b/res-xhdpi/images/error_text.png
index c3a4cc6..ad18851 100644
--- a/res-xhdpi/images/error_text.png
+++ b/res-xhdpi/images/error_text.png
Binary files differ
diff --git a/res-xhdpi/images/installing_security_text.png b/res-xhdpi/images/installing_security_text.png
new file mode 100644
index 0000000..acc6a7c
--- /dev/null
+++ b/res-xhdpi/images/installing_security_text.png
Binary files differ
diff --git a/res-xhdpi/images/installing_text.png b/res-xhdpi/images/installing_text.png
index a4dacd0..32897d0 100644
--- a/res-xhdpi/images/installing_text.png
+++ b/res-xhdpi/images/installing_text.png
Binary files differ
diff --git a/res-xhdpi/images/no_command_text.png b/res-xhdpi/images/no_command_text.png
index eb34e94..eb43c59 100644
--- a/res-xhdpi/images/no_command_text.png
+++ b/res-xhdpi/images/no_command_text.png
Binary files differ
diff --git a/res-xxhdpi/images/erasing_text.png b/res-xxhdpi/images/erasing_text.png
index c87fd52..8ff2b2f 100644
--- a/res-xxhdpi/images/erasing_text.png
+++ b/res-xxhdpi/images/erasing_text.png
Binary files differ
diff --git a/res-xxhdpi/images/error_text.png b/res-xxhdpi/images/error_text.png
index 486e951..658d4ea 100644
--- a/res-xxhdpi/images/error_text.png
+++ b/res-xxhdpi/images/error_text.png
Binary files differ
diff --git a/res-xxhdpi/images/installing_security_text.png b/res-xxhdpi/images/installing_security_text.png
new file mode 100644
index 0000000..23fcaa4
--- /dev/null
+++ b/res-xxhdpi/images/installing_security_text.png
Binary files differ
diff --git a/res-xxhdpi/images/installing_text.png b/res-xxhdpi/images/installing_text.png
index ef6e8f3..fd8e584 100644
--- a/res-xxhdpi/images/installing_text.png
+++ b/res-xxhdpi/images/installing_text.png
Binary files differ
diff --git a/res-xxhdpi/images/no_command_text.png b/res-xxhdpi/images/no_command_text.png
index cc98bb1..23932d6 100644
--- a/res-xxhdpi/images/no_command_text.png
+++ b/res-xxhdpi/images/no_command_text.png
Binary files differ
diff --git a/res-xxxhdpi/images/erasing_text.png b/res-xxxhdpi/images/erasing_text.png
index 612e7a3..0315293 100644
--- a/res-xxxhdpi/images/erasing_text.png
+++ b/res-xxxhdpi/images/erasing_text.png
Binary files differ
diff --git a/res-xxxhdpi/images/error_text.png b/res-xxxhdpi/images/error_text.png
index 50d2fad..dba127f 100644
--- a/res-xxxhdpi/images/error_text.png
+++ b/res-xxxhdpi/images/error_text.png
Binary files differ
diff --git a/res-xxxhdpi/images/installing_security_text.png b/res-xxxhdpi/images/installing_security_text.png
new file mode 100644
index 0000000..6cdbef4
--- /dev/null
+++ b/res-xxxhdpi/images/installing_security_text.png
Binary files differ
diff --git a/res-xxxhdpi/images/installing_text.png b/res-xxxhdpi/images/installing_text.png
index 9bd093b..32511a9 100644
--- a/res-xxxhdpi/images/installing_text.png
+++ b/res-xxxhdpi/images/installing_text.png
Binary files differ
diff --git a/res-xxxhdpi/images/no_command_text.png b/res-xxxhdpi/images/no_command_text.png
index 6354e6a..b6cdd77 100644
--- a/res-xxxhdpi/images/no_command_text.png
+++ b/res-xxxhdpi/images/no_command_text.png
Binary files differ
diff --git a/tests/component/verifier_test.cpp b/tests/component/verifier_test.cpp
index b5d7032..2a78173 100644
--- a/tests/component/verifier_test.cpp
+++ b/tests/component/verifier_test.cpp
@@ -99,30 +99,14 @@
             android::base::StringPrintf("%s%s%s%s", DATA_PATH, NATIVE_TEST_PATH,
                                         TESTDATA_PATH, args[0].c_str());
         if (sysMapFile(package.c_str(), &memmap) != 0) {
-            FAIL() << "Failed to mmap " << package << ": " << strerror(errno)
-                   << "\n";
+            FAIL() << "Failed to mmap " << package << ": " << strerror(errno) << "\n";
         }
 
         for (auto it = ++(args.cbegin()); it != args.cend(); ++it) {
-            if (it->substr(it->length() - 3, it->length()) == "256") {
-                if (certs.empty()) {
-                    FAIL() << "May only specify -sha256 after key type\n";
-                }
-                certs.back().hash_len = SHA256_DIGEST_LENGTH;
-            } else {
-                std::string public_key_file = android::base::StringPrintf(
-                    "%s%s%stest_key_%s.txt", DATA_PATH, NATIVE_TEST_PATH,
-                    TESTDATA_PATH, it->c_str());
-                ASSERT_TRUE(load_keys(public_key_file.c_str(), certs));
-                certs.back().hash_len = SHA_DIGEST_LENGTH;
-            }
-        }
-        if (certs.empty()) {
             std::string public_key_file = android::base::StringPrintf(
-                "%s%s%stest_key_e3.txt", DATA_PATH, NATIVE_TEST_PATH,
-                TESTDATA_PATH);
+                    "%s%s%stestkey_%s.txt", DATA_PATH, NATIVE_TEST_PATH,
+                    TESTDATA_PATH, it->c_str());
             ASSERT_TRUE(load_keys(public_key_file.c_str(), certs));
-            certs.back().hash_len = SHA_DIGEST_LENGTH;
         }
     }
 
@@ -147,37 +131,38 @@
 
 INSTANTIATE_TEST_CASE_P(SingleKeySuccess, VerifierSuccessTest,
         ::testing::Values(
-            std::vector<std::string>({"otasigned.zip", "e3"}),
-            std::vector<std::string>({"otasigned_f4.zip", "f4"}),
-            std::vector<std::string>({"otasigned_sha256.zip", "e3", "sha256"}),
-            std::vector<std::string>({"otasigned_f4_sha256.zip", "f4", "sha256"}),
-            std::vector<std::string>({"otasigned_ecdsa_sha256.zip", "ec", "sha256"})));
+            std::vector<std::string>({"otasigned_v1.zip", "v1"}),
+            std::vector<std::string>({"otasigned_v2.zip", "v2"}),
+            std::vector<std::string>({"otasigned_v3.zip", "v3"}),
+            std::vector<std::string>({"otasigned_v4.zip", "v4"}),
+            std::vector<std::string>({"otasigned_v5.zip", "v5"})));
 
 INSTANTIATE_TEST_CASE_P(MultiKeySuccess, VerifierSuccessTest,
         ::testing::Values(
-            std::vector<std::string>({"otasigned.zip", "f4", "e3"}),
-            std::vector<std::string>({"otasigned_f4.zip", "ec", "f4"}),
-            std::vector<std::string>({"otasigned_sha256.zip", "ec", "e3", "e3", "sha256"}),
-            std::vector<std::string>({"otasigned_f4_sha256.zip", "ec", "sha256", "e3", "f4", "sha256"}),
-            std::vector<std::string>({"otasigned_ecdsa_sha256.zip", "f4", "sha256", "e3", "ec", "sha256"})));
+            std::vector<std::string>({"otasigned_v1.zip", "v1", "v2"}),
+            std::vector<std::string>({"otasigned_v2.zip", "v5", "v2"}),
+            std::vector<std::string>({"otasigned_v3.zip", "v5", "v1", "v3"}),
+            std::vector<std::string>({"otasigned_v4.zip", "v5", "v1", "v4"}),
+            std::vector<std::string>({"otasigned_v5.zip", "v4", "v1", "v5"})));
 
 INSTANTIATE_TEST_CASE_P(WrongKey, VerifierFailureTest,
         ::testing::Values(
-            std::vector<std::string>({"otasigned.zip", "f4"}),
-            std::vector<std::string>({"otasigned_f4.zip", "e3"}),
-            std::vector<std::string>({"otasigned_ecdsa_sha256.zip", "e3", "sha256"})));
+            std::vector<std::string>({"otasigned_v1.zip", "v2"}),
+            std::vector<std::string>({"otasigned_v2.zip", "v1"}),
+            std::vector<std::string>({"otasigned_v3.zip", "v5"}),
+            std::vector<std::string>({"otasigned_v4.zip", "v5"}),
+            std::vector<std::string>({"otasigned_v5.zip", "v3"})));
 
 INSTANTIATE_TEST_CASE_P(WrongHash, VerifierFailureTest,
         ::testing::Values(
-            std::vector<std::string>({"otasigned.zip", "e3", "sha256"}),
-            std::vector<std::string>({"otasigned_f4.zip", "f4", "sha256"}),
-            std::vector<std::string>({"otasigned_sha256.zip"}),
-            std::vector<std::string>({"otasigned_f4_sha256.zip", "f4"}),
-            std::vector<std::string>({"otasigned_ecdsa_sha256.zip"})));
+            std::vector<std::string>({"otasigned_v1.zip", "v3"}),
+            std::vector<std::string>({"otasigned_v2.zip", "v4"}),
+            std::vector<std::string>({"otasigned_v3.zip", "v1"}),
+            std::vector<std::string>({"otasigned_v4.zip", "v2"})));
 
 INSTANTIATE_TEST_CASE_P(BadPackage, VerifierFailureTest,
         ::testing::Values(
-            std::vector<std::string>({"random.zip"}),
-            std::vector<std::string>({"fake-eocd.zip"}),
-            std::vector<std::string>({"alter-metadata.zip"}),
-            std::vector<std::string>({"alter-footer.zip"})));
+            std::vector<std::string>({"random.zip", "v1"}),
+            std::vector<std::string>({"fake-eocd.zip", "v1"}),
+            std::vector<std::string>({"alter-metadata.zip", "v1"}),
+            std::vector<std::string>({"alter-footer.zip", "v1"})));
diff --git a/tests/testdata/otasigned.zip b/tests/testdata/otasigned_v1.zip
similarity index 100%
rename from tests/testdata/otasigned.zip
rename to tests/testdata/otasigned_v1.zip
Binary files differ
diff --git a/tests/testdata/otasigned_f4.zip b/tests/testdata/otasigned_v2.zip
similarity index 100%
rename from tests/testdata/otasigned_f4.zip
rename to tests/testdata/otasigned_v2.zip
Binary files differ
diff --git a/tests/testdata/otasigned_sha256.zip b/tests/testdata/otasigned_v3.zip
similarity index 100%
rename from tests/testdata/otasigned_sha256.zip
rename to tests/testdata/otasigned_v3.zip
Binary files differ
diff --git a/tests/testdata/otasigned_f4_sha256.zip b/tests/testdata/otasigned_v4.zip
similarity index 100%
rename from tests/testdata/otasigned_f4_sha256.zip
rename to tests/testdata/otasigned_v4.zip
Binary files differ
diff --git a/tests/testdata/otasigned_ecdsa_sha256.zip b/tests/testdata/otasigned_v5.zip
similarity index 100%
rename from tests/testdata/otasigned_ecdsa_sha256.zip
rename to tests/testdata/otasigned_v5.zip
Binary files differ
diff --git a/tests/testdata/testkey.pk8 b/tests/testdata/testkey_v1.pk8
similarity index 100%
rename from tests/testdata/testkey.pk8
rename to tests/testdata/testkey_v1.pk8
Binary files differ
diff --git a/tests/testdata/test_key_e3.txt b/tests/testdata/testkey_v1.txt
similarity index 100%
rename from tests/testdata/test_key_e3.txt
rename to tests/testdata/testkey_v1.txt
diff --git a/tests/testdata/testkey.x509.pem b/tests/testdata/testkey_v1.x509.pem
similarity index 100%
rename from tests/testdata/testkey.x509.pem
rename to tests/testdata/testkey_v1.x509.pem
diff --git a/tests/testdata/test_f4.pk8 b/tests/testdata/testkey_v2.pk8
similarity index 100%
rename from tests/testdata/test_f4.pk8
rename to tests/testdata/testkey_v2.pk8
Binary files differ
diff --git a/tests/testdata/test_key_f4.txt b/tests/testdata/testkey_v2.txt
similarity index 100%
rename from tests/testdata/test_key_f4.txt
rename to tests/testdata/testkey_v2.txt
diff --git a/tests/testdata/test_f4.x509.pem b/tests/testdata/testkey_v2.x509.pem
similarity index 100%
rename from tests/testdata/test_f4.x509.pem
rename to tests/testdata/testkey_v2.x509.pem
diff --git a/tests/testdata/testkey_v3.pk8 b/tests/testdata/testkey_v3.pk8
new file mode 120000
index 0000000..18ecf98
--- /dev/null
+++ b/tests/testdata/testkey_v3.pk8
@@ -0,0 +1 @@
+testkey_v1.pk8
\ No newline at end of file
diff --git a/tests/testdata/testkey_v3.txt b/tests/testdata/testkey_v3.txt
new file mode 100644
index 0000000..3208571
--- /dev/null
+++ b/tests/testdata/testkey_v3.txt
@@ -0,0 +1 @@
+v3 {64,0xc926ad21,{1795090719,2141396315,950055447,2581568430,4268923165,1920809988,546586521,3498997798,1776797858,3740060814,1805317999,1429410244,129622599,1422441418,1783893377,1222374759,2563319927,323993566,28517732,609753416,1826472888,215237850,4261642700,4049082591,3228462402,774857746,154822455,2497198897,2758199418,3019015328,2794777644,87251430,2534927978,120774784,571297800,3695899472,2479925187,3811625450,3401832990,2394869647,3267246207,950095497,555058928,414729973,1136544882,3044590084,465547824,4058146728,2731796054,1689838846,3890756939,1048029507,895090649,247140249,178744550,3547885223,3165179243,109881576,3944604415,1044303212,3772373029,2985150306,3737520932,3599964420},{3437017481,3784475129,2800224972,3086222688,251333580,2131931323,512774938,325948880,2657486437,2102694287,3820568226,792812816,1026422502,2053275343,2800889200,3113586810,165549746,4273519969,4065247892,1902789247,772932719,3941848426,3652744109,216871947,3164400649,1942378755,3996765851,1055777370,964047799,629391717,2232744317,3910558992,191868569,2758883837,3682816752,2997714732,2702529250,3570700455,3776873832,3924067546,3555689545,2758825434,1323144535,61311905,1997411085,376844204,213777604,4077323584,9135381,1625809335,2804742137,2952293945,1117190829,4237312782,1825108855,3013147971,1111251351,2568837572,1684324211,2520978805,367251975,810756730,2353784344,1175080310}}
diff --git a/tests/testdata/testkey_sha256.x509.pem b/tests/testdata/testkey_v3.x509.pem
similarity index 100%
rename from tests/testdata/testkey_sha256.x509.pem
rename to tests/testdata/testkey_v3.x509.pem
diff --git a/tests/testdata/testkey_v4.pk8 b/tests/testdata/testkey_v4.pk8
new file mode 120000
index 0000000..683b9a3
--- /dev/null
+++ b/tests/testdata/testkey_v4.pk8
@@ -0,0 +1 @@
+testkey_v2.pk8
\ No newline at end of file
diff --git a/tests/testdata/testkey_v4.txt b/tests/testdata/testkey_v4.txt
new file mode 100644
index 0000000..532cbd5
--- /dev/null
+++ b/tests/testdata/testkey_v4.txt
@@ -0,0 +1 @@
+v4 {64,0xc9bd1f21,{293133087,3210546773,865313125,250921607,3158780490,943703457,1242806226,2986289859,2942743769,2457906415,2719374299,1783459420,149579627,3081531591,3440738617,2788543742,2758457512,1146764939,3699497403,2446203424,1744968926,1159130537,2370028300,3978231572,3392699980,1487782451,1180150567,2841334302,3753960204,961373345,3333628321,748825784,2978557276,1566596926,1613056060,2600292737,1847226629,50398611,1890374404,2878700735,2286201787,1401186359,619285059,731930817,2340993166,1156490245,2992241729,151498140,318782170,3480838990,2100383433,4223552555,3628927011,4247846280,1759029513,4215632601,2719154626,3490334597,1751299340,3487864726,3668753795,4217506054,3748782284,3150295088},{1772626313,445326068,3477676155,1758201194,2986784722,491035581,3922936562,702212696,2979856666,3324974564,2488428922,3056318590,1626954946,664714029,398585816,3964097931,3356701905,2298377729,2040082097,3025491477,539143308,3348777868,2995302452,3602465520,212480763,2691021393,1307177300,704008044,2031136606,1054106474,3838318865,2441343869,1477566916,700949900,2534790355,3353533667,336163563,4106790558,2701448228,1571536379,1103842411,3623110423,1635278839,1577828979,910322800,715583630,138128831,1017877531,2289162787,447994798,1897243165,4121561445,4150719842,2131821093,2262395396,3305771534,980753571,3256525190,3128121808,1072869975,3507939515,4229109952,118381341,2209831334}}
diff --git a/tests/testdata/test_f4_sha256.x509.pem b/tests/testdata/testkey_v4.x509.pem
similarity index 100%
rename from tests/testdata/test_f4_sha256.x509.pem
rename to tests/testdata/testkey_v4.x509.pem
diff --git a/tests/testdata/testkey_ecdsa.pk8 b/tests/testdata/testkey_v5.pk8
similarity index 100%
rename from tests/testdata/testkey_ecdsa.pk8
rename to tests/testdata/testkey_v5.pk8
Binary files differ
diff --git a/tests/testdata/test_key_ec.txt b/tests/testdata/testkey_v5.txt
similarity index 100%
rename from tests/testdata/test_key_ec.txt
rename to tests/testdata/testkey_v5.txt
diff --git a/tests/testdata/testkey_ecdsa.x509.pem b/tests/testdata/testkey_v5.x509.pem
similarity index 100%
rename from tests/testdata/testkey_ecdsa.x509.pem
rename to tests/testdata/testkey_v5.x509.pem
diff --git a/tools/recovery_l10n/README.md b/tools/recovery_l10n/README.md
new file mode 100644
index 0000000..1554f66
--- /dev/null
+++ b/tools/recovery_l10n/README.md
@@ -0,0 +1,33 @@
+# Steps to regenerate background text images under res-*dpi/images/
+
+1.  Build the recovery_l10n app:
+
+    cd bootable/recovery && mma -j32
+
+2.  Install the app on the device (or emulator) with the intended dpi.
+
+    *   For example, we can use Nexus 5 to generate the text images under
+        res-xxhdpi.
+    *   When using the emulator, make sure the NDK version matches the current
+        repository. Otherwise, the app may not work properly.
+
+    adb install $PATH_TO_APP
+
+3.  Run the app, select the string to translate and press the 'go' button.
+
+4.  After the app goes through the strings for all locales, pull the output png
+    file from the device.
+
+    adb root && adb pull /data/data/com.android.recovery_l10n/files/text-out.png
+
+5.  Compress the output file put it under the corresponding directory.
+
+    *   "pngcrush -c 0 ..." converts "text-out.png" into a 1-channel image,
+        which is accepted by Recovery. This also compresses the image file by
+        ~60%.
+    *   zopflipng could further compress the png files by ~10%, more details
+        in https://github.com/google/zopfli/blob/master/README.zopflipng
+    *   If you're using other png compression tools, make sure the final text
+        image works by running graphic tests under the recovery mode.
+
+    pngcrush -c 0 text-out.png $OUTPUT_PNG
diff --git a/tools/recovery_l10n/res/values/strings.xml b/tools/recovery_l10n/res/values/strings.xml
index f6193ab..48d18da 100644
--- a/tools/recovery_l10n/res/values/strings.xml
+++ b/tools/recovery_l10n/res/values/strings.xml
@@ -9,6 +9,7 @@
     <item>erasing</item>
     <item>no_command</item>
     <item>error</item>
+    <item>installing_security</item>
   </string-array>
 
   <!-- Displayed on the screen beneath the animated android while the
diff --git a/tools/recovery_l10n/src/com/android/recovery_l10n/Main.java b/tools/recovery_l10n/src/com/android/recovery_l10n/Main.java
index 3f2bebe..a974fa3 100644
--- a/tools/recovery_l10n/src/com/android/recovery_l10n/Main.java
+++ b/tools/recovery_l10n/src/com/android/recovery_l10n/Main.java
@@ -139,6 +139,7 @@
                     case 1: mStringId = R.string.recovery_erasing; break;
                     case 2: mStringId = R.string.recovery_no_command; break;
                     case 3: mStringId = R.string.recovery_error; break;
+                    case 4: mStringId = R.string.recovery_installing_security; break;
                 }
             }
             @Override public void onNothingSelected(AdapterView parent) { }