diff --git a/libs/input/InputDevice.cpp b/libs/input/InputDevice.cpp
index 5d27bf6..778c453 100644
--- a/libs/input/InputDevice.cpp
+++ b/libs/input/InputDevice.cpp
@@ -20,9 +20,12 @@
 #include <unistd.h>
 #include <ctype.h>
 
+#include <android-base/stringprintf.h>
 #include <input/InputDevice.h>
 #include <input/InputEventLabels.h>
 
+using android::base::StringPrintf;
+
 namespace android {
 
 static const char* CONFIGURATION_FILE_DIR[] = {
@@ -41,8 +44,8 @@
     return isascii(ch) && (isdigit(ch) || isalpha(ch) || ch == '-' || ch == '_');
 }
 
-static void appendInputDeviceConfigurationFileRelativePath(String8& path,
-        const String8& name, InputDeviceConfigurationFileType type) {
+static void appendInputDeviceConfigurationFileRelativePath(std::string& path,
+        const std::string& name, InputDeviceConfigurationFileType type) {
     path.append(CONFIGURATION_FILE_DIR[type]);
     for (size_t i = 0; i < name.length(); i++) {
         char ch = name[i];
@@ -54,28 +57,28 @@
     path.append(CONFIGURATION_FILE_EXTENSION[type]);
 }
 
-String8 getInputDeviceConfigurationFilePathByDeviceIdentifier(
+std::string getInputDeviceConfigurationFilePathByDeviceIdentifier(
         const InputDeviceIdentifier& deviceIdentifier,
         InputDeviceConfigurationFileType type) {
     if (deviceIdentifier.vendor !=0 && deviceIdentifier.product != 0) {
         if (deviceIdentifier.version != 0) {
             // Try vendor product version.
-            String8 versionPath(getInputDeviceConfigurationFilePathByName(
-                    String8::format("Vendor_%04x_Product_%04x_Version_%04x",
+            std::string versionPath = getInputDeviceConfigurationFilePathByName(
+                    StringPrintf("Vendor_%04x_Product_%04x_Version_%04x",
                             deviceIdentifier.vendor, deviceIdentifier.product,
                             deviceIdentifier.version),
-                    type));
-            if (!versionPath.isEmpty()) {
+                    type);
+            if (!versionPath.empty()) {
                 return versionPath;
             }
         }
 
         // Try vendor product.
-        String8 productPath(getInputDeviceConfigurationFilePathByName(
-                String8::format("Vendor_%04x_Product_%04x",
+        std::string productPath = getInputDeviceConfigurationFilePathByName(
+                StringPrintf("Vendor_%04x_Product_%04x",
                         deviceIdentifier.vendor, deviceIdentifier.product),
-                type));
-        if (!productPath.isEmpty()) {
+                type);
+        if (!productPath.empty()) {
             return productPath;
         }
     }
@@ -84,22 +87,25 @@
     return getInputDeviceConfigurationFilePathByName(deviceIdentifier.name, type);
 }
 
-String8 getInputDeviceConfigurationFilePathByName(
-        const String8& name, InputDeviceConfigurationFileType type) {
+std::string getInputDeviceConfigurationFilePathByName(
+        const std::string& name, InputDeviceConfigurationFileType type) {
     // Search system repository.
-    String8 path;
+    std::string path;
 
     // Treblized input device config files will be located /odm/usr or /vendor/usr.
     const char *rootsForPartition[] {"/odm", "/vendor", getenv("ANDROID_ROOT")};
     for (size_t i = 0; i < size(rootsForPartition); i++) {
-        path.setTo(rootsForPartition[i]);
-        path.append("/usr/");
+        if (rootsForPartition[i] == nullptr) {
+            continue;
+        }
+        path = rootsForPartition[i];
+        path += "/usr/";
         appendInputDeviceConfigurationFileRelativePath(path, name, type);
 #if DEBUG_PROBE
         ALOGD("Probing for system provided input device configuration file: path='%s'",
-              path.string());
+              path.c_str());
 #endif
-        if (!access(path.string(), R_OK)) {
+        if (!access(path.c_str(), R_OK)) {
 #if DEBUG_PROBE
             ALOGD("Found");
 #endif
@@ -109,13 +115,17 @@
 
     // Search user repository.
     // TODO Should only look here if not in safe mode.
-    path.setTo(getenv("ANDROID_DATA"));
-    path.append("/system/devices/");
+    path = "";
+    char *androidData = getenv("ANDROID_DATA");
+    if (androidData != nullptr) {
+        path += androidData;
+    }
+    path += "/system/devices/";
     appendInputDeviceConfigurationFileRelativePath(path, name, type);
 #if DEBUG_PROBE
-    ALOGD("Probing for system user input device configuration file: path='%s'", path.string());
+    ALOGD("Probing for system user input device configuration file: path='%s'", path.c_str());
 #endif
-    if (!access(path.string(), R_OK)) {
+    if (!access(path.c_str(), R_OK)) {
 #if DEBUG_PROBE
         ALOGD("Found");
 #endif
@@ -125,16 +135,16 @@
     // Not found.
 #if DEBUG_PROBE
     ALOGD("Probe failed to find input device configuration file: name='%s', type=%d",
-            name.string(), type);
+            name.c_str(), type);
 #endif
-    return String8();
+    return "";
 }
 
 
 // --- InputDeviceInfo ---
 
 InputDeviceInfo::InputDeviceInfo() {
-    initialize(-1, 0, -1, InputDeviceIdentifier(), String8(), false, false);
+    initialize(-1, 0, -1, InputDeviceIdentifier(), "", false, false);
 }
 
 InputDeviceInfo::InputDeviceInfo(const InputDeviceInfo& other) :
@@ -150,7 +160,7 @@
 }
 
 void InputDeviceInfo::initialize(int32_t id, int32_t generation, int32_t controllerNumber,
-        const InputDeviceIdentifier& identifier, const String8& alias, bool isExternal,
+        const InputDeviceIdentifier& identifier, const std::string& alias, bool isExternal,
         bool hasMic) {
     mId = id;
     mGeneration = generation;
diff --git a/libs/input/KeyCharacterMap.cpp b/libs/input/KeyCharacterMap.cpp
index 26747bd..e189d20 100644
--- a/libs/input/KeyCharacterMap.cpp
+++ b/libs/input/KeyCharacterMap.cpp
@@ -106,14 +106,14 @@
     }
 }
 
-status_t KeyCharacterMap::load(const String8& filename,
+status_t KeyCharacterMap::load(const std::string& filename,
         Format format, sp<KeyCharacterMap>* outMap) {
     outMap->clear();
 
     Tokenizer* tokenizer;
-    status_t status = Tokenizer::open(filename, &tokenizer);
+    status_t status = Tokenizer::open(String8(filename.c_str()), &tokenizer);
     if (status) {
-        ALOGE("Error %d opening key character map file %s.", status, filename.string());
+        ALOGE("Error %d opening key character map file %s.", status, filename.c_str());
     } else {
         status = load(tokenizer, format, outMap);
         delete tokenizer;
@@ -121,12 +121,12 @@
     return status;
 }
 
-status_t KeyCharacterMap::loadContents(const String8& filename, const char* contents,
+status_t KeyCharacterMap::loadContents(const std::string& filename, const char* contents,
         Format format, sp<KeyCharacterMap>* outMap) {
     outMap->clear();
 
     Tokenizer* tokenizer;
-    status_t status = Tokenizer::fromContents(filename, contents, &tokenizer);
+    status_t status = Tokenizer::fromContents(String8(filename.c_str()), contents, &tokenizer);
     if (status) {
         ALOGE("Error %d opening key character map.", status);
     } else {
@@ -944,7 +944,7 @@
             properties.add(Property(PROPERTY_NUMBER));
         } else {
             int32_t metaState;
-            status_t status = parseModifier(token, &metaState);
+            status_t status = parseModifier(token.string(), &metaState);
             if (status) {
                 ALOGE("%s: Expected a property name or modifier, got '%s'.",
                         mTokenizer->getLocation().string(), token.string());
@@ -1137,7 +1137,7 @@
     return NO_ERROR;
 }
 
-status_t KeyCharacterMap::Parser::parseModifier(const String8& token, int32_t* outMetaState) {
+status_t KeyCharacterMap::Parser::parseModifier(const std::string& token, int32_t* outMetaState) {
     if (token == "base") {
         *outMetaState = 0;
         return NO_ERROR;
@@ -1145,7 +1145,7 @@
 
     int32_t combinedMeta = 0;
 
-    const char* str = token.string();
+    const char* str = token.c_str();
     const char* start = str;
     for (const char* cur = str; ; cur++) {
         char ch = *cur;
@@ -1164,7 +1164,7 @@
             }
             if (combinedMeta & metaState) {
                 ALOGE("%s: Duplicate modifier combination '%s'.",
-                        mTokenizer->getLocation().string(), token.string());
+                        mTokenizer->getLocation().string(), token.c_str());
                 return BAD_VALUE;
             }
 
diff --git a/libs/input/KeyLayoutMap.cpp b/libs/input/KeyLayoutMap.cpp
index c440078..88cb0db 100644
--- a/libs/input/KeyLayoutMap.cpp
+++ b/libs/input/KeyLayoutMap.cpp
@@ -49,13 +49,13 @@
 KeyLayoutMap::~KeyLayoutMap() {
 }
 
-status_t KeyLayoutMap::load(const String8& filename, sp<KeyLayoutMap>* outMap) {
+status_t KeyLayoutMap::load(const std::string& filename, sp<KeyLayoutMap>* outMap) {
     outMap->clear();
 
     Tokenizer* tokenizer;
-    status_t status = Tokenizer::open(filename, &tokenizer);
+    status_t status = Tokenizer::open(String8(filename.c_str()), &tokenizer);
     if (status) {
-        ALOGE("Error %d opening key layout map file %s.", status, filename.string());
+        ALOGE("Error %d opening key layout map file %s.", status, filename.c_str());
     } else {
         sp<KeyLayoutMap> map = new KeyLayoutMap();
         if (!map.get()) {
diff --git a/libs/input/Keyboard.cpp b/libs/input/Keyboard.cpp
index 11842ee..0c22bfe 100644
--- a/libs/input/Keyboard.cpp
+++ b/libs/input/Keyboard.cpp
@@ -45,22 +45,22 @@
         String8 keyLayoutName;
         if (deviceConfiguration->tryGetProperty(String8("keyboard.layout"),
                 keyLayoutName)) {
-            status_t status = loadKeyLayout(deviceIdenfifier, keyLayoutName);
+            status_t status = loadKeyLayout(deviceIdenfifier, keyLayoutName.c_str());
             if (status == NAME_NOT_FOUND) {
                 ALOGE("Configuration for keyboard device '%s' requested keyboard layout '%s' but "
                         "it was not found.",
-                        deviceIdenfifier.name.string(), keyLayoutName.string());
+                        deviceIdenfifier.name.c_str(), keyLayoutName.string());
             }
         }
 
         String8 keyCharacterMapName;
         if (deviceConfiguration->tryGetProperty(String8("keyboard.characterMap"),
                 keyCharacterMapName)) {
-            status_t status = loadKeyCharacterMap(deviceIdenfifier, keyCharacterMapName);
+            status_t status = loadKeyCharacterMap(deviceIdenfifier, keyCharacterMapName.c_str());
             if (status == NAME_NOT_FOUND) {
                 ALOGE("Configuration for keyboard device '%s' requested keyboard character "
                         "map '%s' but it was not found.",
-                        deviceIdenfifier.name.string(), keyLayoutName.string());
+                        deviceIdenfifier.name.c_str(), keyLayoutName.string());
             }
         }
 
@@ -70,30 +70,30 @@
     }
 
     // Try searching by device identifier.
-    if (probeKeyMap(deviceIdenfifier, String8::empty())) {
+    if (probeKeyMap(deviceIdenfifier, "")) {
         return OK;
     }
 
     // Fall back on the Generic key map.
     // TODO Apply some additional heuristics here to figure out what kind of
     //      generic key map to use (US English, etc.) for typical external keyboards.
-    if (probeKeyMap(deviceIdenfifier, String8("Generic"))) {
+    if (probeKeyMap(deviceIdenfifier, "Generic")) {
         return OK;
     }
 
     // Try the Virtual key map as a last resort.
-    if (probeKeyMap(deviceIdenfifier, String8("Virtual"))) {
+    if (probeKeyMap(deviceIdenfifier, "Virtual")) {
         return OK;
     }
 
     // Give up!
     ALOGE("Could not determine key map for device '%s' and no default key maps were found!",
-            deviceIdenfifier.name.string());
+            deviceIdenfifier.name.c_str());
     return NAME_NOT_FOUND;
 }
 
 bool KeyMap::probeKeyMap(const InputDeviceIdentifier& deviceIdentifier,
-        const String8& keyMapName) {
+        const std::string& keyMapName) {
     if (!haveKeyLayout()) {
         loadKeyLayout(deviceIdentifier, keyMapName);
     }
@@ -104,10 +104,10 @@
 }
 
 status_t KeyMap::loadKeyLayout(const InputDeviceIdentifier& deviceIdentifier,
-        const String8& name) {
-    String8 path(getPath(deviceIdentifier, name,
+        const std::string& name) {
+    std::string path(getPath(deviceIdentifier, name,
             INPUT_DEVICE_CONFIGURATION_FILE_TYPE_KEY_LAYOUT));
-    if (path.isEmpty()) {
+    if (path.empty()) {
         return NAME_NOT_FOUND;
     }
 
@@ -116,15 +116,15 @@
         return status;
     }
 
-    keyLayoutFile.setTo(path);
+    keyLayoutFile = path;
     return OK;
 }
 
 status_t KeyMap::loadKeyCharacterMap(const InputDeviceIdentifier& deviceIdentifier,
-        const String8& name) {
-    String8 path(getPath(deviceIdentifier, name,
-            INPUT_DEVICE_CONFIGURATION_FILE_TYPE_KEY_CHARACTER_MAP));
-    if (path.isEmpty()) {
+        const std::string& name) {
+    std::string path = getPath(deviceIdentifier, name,
+            INPUT_DEVICE_CONFIGURATION_FILE_TYPE_KEY_CHARACTER_MAP);
+    if (path.empty()) {
         return NAME_NOT_FOUND;
     }
 
@@ -134,13 +134,13 @@
         return status;
     }
 
-    keyCharacterMapFile.setTo(path);
+    keyCharacterMapFile = path;
     return OK;
 }
 
-String8 KeyMap::getPath(const InputDeviceIdentifier& deviceIdentifier,
-        const String8& name, InputDeviceConfigurationFileType type) {
-    return name.isEmpty()
+std::string KeyMap::getPath(const InputDeviceIdentifier& deviceIdentifier,
+        const std::string& name, InputDeviceConfigurationFileType type) {
+    return name.empty()
             ? getInputDeviceConfigurationFilePathByDeviceIdentifier(deviceIdentifier, type)
             : getInputDeviceConfigurationFilePathByName(name, type);
 }
@@ -174,7 +174,7 @@
         }
     }
 
-    return strstr(deviceIdentifier.name.string(), "-keypad");
+    return strstr(deviceIdentifier.name.c_str(), "-keypad");
 }
 
 static int32_t setEphemeralMetaState(int32_t mask, bool down, int32_t oldMetaState) {
diff --git a/libs/input/VirtualKeyMap.cpp b/libs/input/VirtualKeyMap.cpp
index 9932973..3ec53bf 100644
--- a/libs/input/VirtualKeyMap.cpp
+++ b/libs/input/VirtualKeyMap.cpp
@@ -46,13 +46,13 @@
 VirtualKeyMap::~VirtualKeyMap() {
 }
 
-status_t VirtualKeyMap::load(const String8& filename, VirtualKeyMap** outMap) {
+status_t VirtualKeyMap::load(const std::string& filename, VirtualKeyMap** outMap) {
     *outMap = nullptr;
 
     Tokenizer* tokenizer;
-    status_t status = Tokenizer::open(filename, &tokenizer);
+    status_t status = Tokenizer::open(String8(filename.c_str()), &tokenizer);
     if (status) {
-        ALOGE("Error %d opening virtual key map file %s.", status, filename.string());
+        ALOGE("Error %d opening virtual key map file %s.", status, filename.c_str());
     } else {
         VirtualKeyMap* map = new VirtualKeyMap();
         if (!map) {