diff --git a/framework/src/android/net/BpfNetMapsUtils.java b/framework/src/android/net/BpfNetMapsUtils.java
index 11d610c..0be30bb 100644
--- a/framework/src/android/net/BpfNetMapsUtils.java
+++ b/framework/src/android/net/BpfNetMapsUtils.java
@@ -125,13 +125,11 @@
         return sj.toString();
     }
 
-    public static final boolean PRE_T = !SdkLevel.isAtLeastT();
-
     /**
      * Throw UnsupportedOperationException if SdkLevel is before T.
      */
     public static void throwIfPreT(final String msg) {
-        if (PRE_T) {
+        if (!SdkLevel.isAtLeastT()) {
             throw new UnsupportedOperationException(msg);
         }
     }
diff --git a/service-t/lint-baseline.xml b/service-t/lint-baseline.xml
index 7f05b8c..e4b92d6 100644
--- a/service-t/lint-baseline.xml
+++ b/service-t/lint-baseline.xml
@@ -3,17 +3,6 @@
 
     <issue
         id="NewApi"
-        message="Call requires API level 31 (current min is 30): `BpfMap`"
-        errorLine1="                return new BpfMap&lt;&gt;(IFACE_INDEX_NAME_MAP_PATH, BpfMap.BPF_F_RDWR,"
-        errorLine2="                       ~~~~~~~~~~~~">
-        <location
-            file="packages/modules/Connectivity/service-t/src/com/android/server/net/BpfInterfaceMapUpdater.java"
-            line="69"
-            column="24"/>
-    </issue>
-
-    <issue
-        id="NewApi"
         message="Call requires API level 31 (current min is 30): `new android.net.EthernetNetworkSpecifier`"
         errorLine1="                .setNetworkSpecifier(new EthernetNetworkSpecifier(ifaceName))"
         errorLine2="                                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~">
diff --git a/service-t/native/libs/libnetworkstats/BpfNetworkStats.cpp b/service-t/native/libs/libnetworkstats/BpfNetworkStats.cpp
index 8a58e56..def5f88 100644
--- a/service-t/native/libs/libnetworkstats/BpfNetworkStats.cpp
+++ b/service-t/native/libs/libnetworkstats/BpfNetworkStats.cpp
@@ -85,12 +85,12 @@
             [iface, stats, &ifaceNameMap, &unknownIfaceBytesTotal](
                     const uint32_t& key,
                     const BpfMapRO<uint32_t, StatsValue>& ifaceStatsMap) -> Result<void> {
-        IfaceValue ifname;
-        if (getIfaceNameFromMap(ifaceNameMap, ifaceStatsMap, key, ifname, key,
-                                &unknownIfaceBytesTotal)) {
+        Result<IfaceValue> ifname = ifaceNameMap.readValue(key);
+        if (!ifname.ok()) {
+            maybeLogUnknownIface(key, ifaceStatsMap, key, &unknownIfaceBytesTotal);
             return Result<void>();
         }
-        if (!iface || !strcmp(iface, ifname.name)) {
+        if (!iface || !strcmp(iface, ifname.value().name)) {
             Result<StatsValue> statsEntry = ifaceStatsMap.readValue(key);
             if (!statsEntry.ok()) {
                 return statsEntry.error();
@@ -144,16 +144,16 @@
             [&lines, &unknownIfaceBytesTotal, &ifaceMap](
                     const StatsKey& key,
                     const BpfMapRO<StatsKey, StatsValue>& statsMap) -> Result<void> {
-        IfaceValue ifname;
-        if (getIfaceNameFromMap(ifaceMap, statsMap, key.ifaceIndex, ifname, key,
-                                &unknownIfaceBytesTotal)) {
+        Result<IfaceValue> ifname = ifaceMap.readValue(key.ifaceIndex);
+        if (!ifname.ok()) {
+            maybeLogUnknownIface(key.ifaceIndex, statsMap, key, &unknownIfaceBytesTotal);
             return Result<void>();
         }
         Result<StatsValue> statsEntry = statsMap.readValue(key);
         if (!statsEntry.ok()) {
             return base::ResultError(statsEntry.error().message(), statsEntry.error().code());
         }
-        stats_line newLine = populateStatsEntry(key, statsEntry.value(), ifname);
+        stats_line newLine = populateStatsEntry(key, statsEntry.value(), ifname.value());
         lines.push_back(newLine);
         if (newLine.tag) {
             // account tagged traffic in the untagged stats (for historical reasons?)
@@ -234,8 +234,9 @@
     const auto processDetailIfaceStats = [&lines, &unknownIfaceBytesTotal, &ifaceMap, &statsMap](
                                              const uint32_t& key, const StatsValue& value,
                                              const BpfMapRO<uint32_t, StatsValue>&) {
-        IfaceValue ifname;
-        if (getIfaceNameFromMap(ifaceMap, statsMap, key, ifname, key, &unknownIfaceBytesTotal)) {
+        Result<IfaceValue> ifname = ifaceMap.readValue(key);
+        if (!ifname.ok()) {
+            maybeLogUnknownIface(key, statsMap, key, &unknownIfaceBytesTotal);
             return Result<void>();
         }
         StatsKey fakeKey = {
@@ -243,7 +244,7 @@
                 .tag = (uint32_t)TAG_NONE,
                 .counterSet = (uint32_t)SET_ALL,
         };
-        lines.push_back(populateStatsEntry(fakeKey, value, ifname));
+        lines.push_back(populateStatsEntry(fakeKey, value, ifname.value()));
         return Result<void>();
     };
     Result<void> res = statsMap.iterateWithValue(processDetailIfaceStats);
diff --git a/service-t/native/libs/libnetworkstats/BpfNetworkStatsTest.cpp b/service-t/native/libs/libnetworkstats/BpfNetworkStatsTest.cpp
index 2c01904..57822fc 100644
--- a/service-t/native/libs/libnetworkstats/BpfNetworkStatsTest.cpp
+++ b/service-t/native/libs/libnetworkstats/BpfNetworkStatsTest.cpp
@@ -352,14 +352,16 @@
             .counterSet = TEST_COUNTERSET0,
             .ifaceIndex = ifaceIndex,
     };
-    IfaceValue ifname;
     int64_t unknownIfaceBytesTotal = 0;
-    ASSERT_EQ(-ENODEV, getIfaceNameFromMap(mFakeIfaceIndexNameMap, mFakeStatsMap, ifaceIndex,
-                                           ifname, curKey, &unknownIfaceBytesTotal));
+    ASSERT_EQ(false, mFakeIfaceIndexNameMap.readValue(ifaceIndex).ok());
+    maybeLogUnknownIface(ifaceIndex, mFakeStatsMap, curKey, &unknownIfaceBytesTotal);
+
     ASSERT_EQ(((int64_t)(TEST_BYTES0 * 20 + TEST_BYTES1 * 20)), unknownIfaceBytesTotal);
     curKey.ifaceIndex = IFACE_INDEX2;
-    ASSERT_EQ(-ENODEV, getIfaceNameFromMap(mFakeIfaceIndexNameMap, mFakeStatsMap, ifaceIndex,
-                                           ifname, curKey, &unknownIfaceBytesTotal));
+
+    ASSERT_EQ(false, mFakeIfaceIndexNameMap.readValue(ifaceIndex).ok());
+    maybeLogUnknownIface(ifaceIndex, mFakeStatsMap, curKey, &unknownIfaceBytesTotal);
+
     ASSERT_EQ(-1, unknownIfaceBytesTotal);
     std::vector<stats_line> lines;
     // TODO: find a way to test the total of unknown Iface Bytes go above limit.
diff --git a/service-t/native/libs/libnetworkstats/include/netdbpf/BpfNetworkStats.h b/service-t/native/libs/libnetworkstats/include/netdbpf/BpfNetworkStats.h
index 0f28c1d..173dee4 100644
--- a/service-t/native/libs/libnetworkstats/include/netdbpf/BpfNetworkStats.h
+++ b/service-t/native/libs/libnetworkstats/include/netdbpf/BpfNetworkStats.h
@@ -71,20 +71,6 @@
                                        const BpfMapRO<uint32_t, IfaceValue>& ifaceMap);
 // For test only
 int cleanStatsMapInternal(const base::unique_fd& cookieTagMap, const base::unique_fd& tagStatsMap);
-// For test only
-template <class Key>
-int getIfaceNameFromMap(const BpfMapRO<uint32_t, IfaceValue>& ifaceMap,
-                        const BpfMapRO<Key, StatsValue>& statsMap,
-                        uint32_t ifaceIndex, IfaceValue& ifname,
-                        const Key& curKey, int64_t* unknownIfaceBytesTotal) {
-    auto iface = ifaceMap.readValue(ifaceIndex);
-    if (!iface.ok()) {
-        maybeLogUnknownIface(ifaceIndex, statsMap, curKey, unknownIfaceBytesTotal);
-        return -ENODEV;
-    }
-    ifname = iface.value();
-    return 0;
-}
 
 template <class Key>
 void maybeLogUnknownIface(int ifaceIndex, const BpfMapRO<Key, StatsValue>& statsMap,
diff --git a/service/lint-baseline.xml b/service/lint-baseline.xml
index a091a2b..b09589c 100644
--- a/service/lint-baseline.xml
+++ b/service/lint-baseline.xml
@@ -3,72 +3,6 @@
 
     <issue
         id="NewApi"
-        message="Call requires API level 31 (current min is 30): `BpfMap`"
-        errorLine1="            return new BpfMap&lt;&gt;("
-        errorLine2="                   ~~~~~~~~~~~~">
-        <location
-            file="packages/modules/Connectivity/service/src/com/android/server/BpfNetMaps.java"
-            line="189"
-            column="20"/>
-    </issue>
-
-    <issue
-        id="NewApi"
-        message="Call requires API level 31 (current min is 30): `BpfMap`"
-        errorLine1="            return new BpfMap&lt;&gt;("
-        errorLine2="                   ~~~~~~~~~~~~">
-        <location
-            file="packages/modules/Connectivity/service/src/com/android/server/BpfNetMaps.java"
-            line="198"
-            column="20"/>
-    </issue>
-
-    <issue
-        id="NewApi"
-        message="Call requires API level 31 (current min is 30): `BpfMap`"
-        errorLine1="            return new BpfMap&lt;&gt;("
-        errorLine2="                   ~~~~~~~~~~~~">
-        <location
-            file="packages/modules/Connectivity/service/src/com/android/server/BpfNetMaps.java"
-            line="207"
-            column="20"/>
-    </issue>
-
-    <issue
-        id="NewApi"
-        message="Call requires API level 31 (current min is 30): `BpfMap`"
-        errorLine1="            return new BpfMap&lt;&gt;(COOKIE_TAG_MAP_PATH, BpfMap.BPF_F_RDWR,"
-        errorLine2="                   ~~~~~~~~~~~~">
-        <location
-            file="packages/modules/Connectivity/service/src/com/android/server/BpfNetMaps.java"
-            line="216"
-            column="20"/>
-    </issue>
-
-    <issue
-        id="NewApi"
-        message="Call requires API level 31 (current min is 30): `BpfMap`"
-        errorLine1="            return new BpfMap&lt;&gt;("
-        errorLine2="                   ~~~~~~~~~~~~">
-        <location
-            file="packages/modules/Connectivity/service/src/com/android/server/BpfNetMaps.java"
-            line="225"
-            column="20"/>
-    </issue>
-
-    <issue
-        id="NewApi"
-        message="Call requires API level 31 (current min is 30): `BpfMap`"
-        errorLine1="            return new BpfMap&lt;&gt;(INGRESS_DISCARD_MAP_PATH, BpfMap.BPF_F_RDWR,"
-        errorLine2="                   ~~~~~~~~~~~~">
-        <location
-            file="packages/modules/Connectivity/service/src/com/android/server/BpfNetMaps.java"
-            line="234"
-            column="20"/>
-    </issue>
-
-    <issue
-        id="NewApi"
         message="Call requires API level 31 (current min is 30): `BpfBitmap`"
         errorLine1="                return new BpfBitmap(BLOCKED_PORTS_MAP_PATH);"
         errorLine2="                       ~~~~~~~~~~~~~">
diff --git a/service/src/com/android/server/BpfNetMaps.java b/service/src/com/android/server/BpfNetMaps.java
index aa40285..a7fddd0 100644
--- a/service/src/com/android/server/BpfNetMaps.java
+++ b/service/src/com/android/server/BpfNetMaps.java
@@ -31,7 +31,6 @@
 import static android.net.BpfNetMapsConstants.UID_OWNER_MAP_PATH;
 import static android.net.BpfNetMapsConstants.UID_PERMISSION_MAP_PATH;
 import static android.net.BpfNetMapsConstants.UID_RULES_CONFIGURATION_KEY;
-import static android.net.BpfNetMapsUtils.PRE_T;
 import static android.net.BpfNetMapsUtils.getMatchByFirewallChain;
 import static android.net.BpfNetMapsUtils.isFirewallAllowList;
 import static android.net.BpfNetMapsUtils.matchToString;
@@ -68,6 +67,7 @@
 
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.modules.utils.BackgroundThread;
+import com.android.modules.utils.build.SdkLevel;
 import com.android.net.module.util.BpfDump;
 import com.android.net.module.util.BpfMap;
 import com.android.net.module.util.IBpfMap;
@@ -95,7 +95,7 @@
  */
 public class BpfNetMaps {
     static {
-        if (!PRE_T) {
+        if (SdkLevel.isAtLeastT()) {
             System.loadLibrary("service-connectivity");
         }
     }
@@ -184,6 +184,7 @@
         sIngressDiscardMap = ingressDiscardMap;
     }
 
+    @RequiresApi(Build.VERSION_CODES.TIRAMISU)
     private static IBpfMap<S32, U32> getConfigurationMap() {
         try {
             return new BpfMap<>(
@@ -193,6 +194,7 @@
         }
     }
 
+    @RequiresApi(Build.VERSION_CODES.TIRAMISU)
     private static IBpfMap<S32, UidOwnerValue> getUidOwnerMap() {
         try {
             return new BpfMap<>(
@@ -202,6 +204,7 @@
         }
     }
 
+    @RequiresApi(Build.VERSION_CODES.TIRAMISU)
     private static IBpfMap<S32, U8> getUidPermissionMap() {
         try {
             return new BpfMap<>(
@@ -211,6 +214,7 @@
         }
     }
 
+    @RequiresApi(Build.VERSION_CODES.TIRAMISU)
     private static IBpfMap<CookieTagMapKey, CookieTagMapValue> getCookieTagMap() {
         try {
             return new BpfMap<>(COOKIE_TAG_MAP_PATH,
@@ -220,6 +224,7 @@
         }
     }
 
+    @RequiresApi(Build.VERSION_CODES.TIRAMISU)
     private static IBpfMap<S32, U8> getDataSaverEnabledMap() {
         try {
             return new BpfMap<>(
@@ -229,6 +234,7 @@
         }
     }
 
+    @RequiresApi(Build.VERSION_CODES.TIRAMISU)
     private static IBpfMap<IngressDiscardKey, IngressDiscardValue> getIngressDiscardMap() {
         try {
             return new BpfMap<>(INGRESS_DISCARD_MAP_PATH,
@@ -238,6 +244,7 @@
         }
     }
 
+    @RequiresApi(Build.VERSION_CODES.TIRAMISU)
     private static void initBpfMaps() {
         if (sConfigurationMap == null) {
             sConfigurationMap = getConfigurationMap();
@@ -295,6 +302,7 @@
      * Initializes the class if it is not already initialized. This method will open maps but not
      * cause any other effects. This method may be called multiple times on any thread.
      */
+    @RequiresApi(Build.VERSION_CODES.TIRAMISU)
     private static synchronized void ensureInitialized(final Context context) {
         if (sInitialized) return;
         initBpfMaps();
@@ -348,7 +356,7 @@
     public BpfNetMaps(final Context context) {
         this(context, null);
 
-        if (PRE_T) throw new IllegalArgumentException("BpfNetMaps need to use netd before T");
+        if (!SdkLevel.isAtLeastT()) throw new IllegalArgumentException("BpfNetMaps need to use netd before T");
     }
 
     public BpfNetMaps(final Context context, final INetd netd) {
@@ -357,7 +365,7 @@
 
     @VisibleForTesting
     public BpfNetMaps(final Context context, final INetd netd, final Dependencies deps) {
-        if (!PRE_T) {
+        if (SdkLevel.isAtLeastT()) {
             ensureInitialized(context);
         }
         mNetd = netd;
@@ -371,7 +379,7 @@
     }
 
     private void throwIfPreT(final String msg) {
-        if (PRE_T) {
+        if (!SdkLevel.isAtLeastT()) {
             throw new UnsupportedOperationException(msg);
         }
     }
@@ -712,7 +720,7 @@
      *                                  cause of the failure.
      */
     public void addUidInterfaceRules(final String ifName, final int[] uids) throws RemoteException {
-        if (PRE_T) {
+        if (!SdkLevel.isAtLeastT()) {
             mNetd.firewallAddUidInterfaceRules(ifName, uids);
             return;
         }
@@ -750,7 +758,7 @@
      *                                  cause of the failure.
      */
     public void removeUidInterfaceRules(final int[] uids) throws RemoteException {
-        if (PRE_T) {
+        if (!SdkLevel.isAtLeastT()) {
             mNetd.firewallRemoveUidInterfaceRules(uids);
             return;
         }
@@ -829,7 +837,7 @@
      * @throws RemoteException when netd has crashed.
      */
     public void setNetPermForUids(final int permissions, final int[] uids) throws RemoteException {
-        if (PRE_T) {
+        if (!SdkLevel.isAtLeastT()) {
             mNetd.trafficSetNetPermForUids(permissions, uids);
             return;
         }
@@ -1019,7 +1027,7 @@
     @RequiresApi(Build.VERSION_CODES.TIRAMISU)
     public void dump(final IndentingPrintWriter pw, final FileDescriptor fd, boolean verbose)
             throws IOException, ServiceSpecificException {
-        if (PRE_T) {
+        if (!SdkLevel.isAtLeastT()) {
             throw new ServiceSpecificException(
                     EOPNOTSUPP, "dumpsys connectivity trafficcontroller dump not available on pre-T"
                     + " devices, use dumpsys netd trafficcontroller instead.");
diff --git a/thread/framework/java/android/net/thread/ThreadNetworkException.java b/thread/framework/java/android/net/thread/ThreadNetworkException.java
index 4fd445b..af0a84b 100644
--- a/thread/framework/java/android/net/thread/ThreadNetworkException.java
+++ b/thread/framework/java/android/net/thread/ThreadNetworkException.java
@@ -124,8 +124,8 @@
     public static final int ERROR_RESOURCE_EXHAUSTED = 10;
 
     /**
-     * The operation failed because of an unknown error in the system. This typically indicates
-     * that the caller doesn't understand error codes added in newer Android versions.
+     * The operation failed because of an unknown error in the system. This typically indicates that
+     * the caller doesn't understand error codes added in newer Android versions.
      */
     public static final int ERROR_UNKNOWN = 11;
 
diff --git a/thread/service/java/com/android/server/thread/ThreadNetworkCountryCode.java b/thread/service/java/com/android/server/thread/ThreadNetworkCountryCode.java
index b7b6233..23aeb93 100644
--- a/thread/service/java/com/android/server/thread/ThreadNetworkCountryCode.java
+++ b/thread/service/java/com/android/server/thread/ThreadNetworkCountryCode.java
@@ -31,6 +31,7 @@
 import android.net.wifi.WifiManager;
 import android.net.wifi.WifiManager.ActiveCountryCodeChangedCallback;
 import android.os.Build;
+import android.sysprop.ThreadNetworkProperties;
 import android.telephony.SubscriptionInfo;
 import android.telephony.SubscriptionManager;
 import android.telephony.TelephonyManager;
@@ -53,8 +54,8 @@
 
 /**
  * Provide functions for making changes to Thread Network country code. This Country Code is from
- * location, WiFi or telephony configuration. This class sends Country Code to Thread Network native
- * layer.
+ * location, WiFi, telephony or OEM configuration. This class sends Country Code to Thread Network
+ * native layer.
  *
  * <p>This class is thread-safe.
  */
@@ -77,6 +78,7 @@
             value = {
                 COUNTRY_CODE_SOURCE_DEFAULT,
                 COUNTRY_CODE_SOURCE_LOCATION,
+                COUNTRY_CODE_SOURCE_OEM,
                 COUNTRY_CODE_SOURCE_OVERRIDE,
                 COUNTRY_CODE_SOURCE_TELEPHONY,
                 COUNTRY_CODE_SOURCE_TELEPHONY_LAST,
@@ -86,6 +88,7 @@
 
     private static final String COUNTRY_CODE_SOURCE_DEFAULT = "Default";
     private static final String COUNTRY_CODE_SOURCE_LOCATION = "Location";
+    private static final String COUNTRY_CODE_SOURCE_OEM = "Oem";
     private static final String COUNTRY_CODE_SOURCE_OVERRIDE = "Override";
     private static final String COUNTRY_CODE_SOURCE_TELEPHONY = "Telephony";
     private static final String COUNTRY_CODE_SOURCE_TELEPHONY_LAST = "TelephonyLast";
@@ -111,6 +114,7 @@
     @Nullable private CountryCodeInfo mWifiCountryCodeInfo;
     @Nullable private CountryCodeInfo mTelephonyCountryCodeInfo;
     @Nullable private CountryCodeInfo mTelephonyLastCountryCodeInfo;
+    @Nullable private CountryCodeInfo mOemCountryCodeInfo;
 
     /** Container class to store Thread country code information. */
     private static final class CountryCodeInfo {
@@ -118,13 +122,35 @@
         @CountryCodeSource private String mSource;
         private final Instant mUpdatedTimestamp;
 
+        /**
+         * Constructs a new {@code CountryCodeInfo} from the given country code, country code source
+         * and country coode created time.
+         *
+         * @param countryCode a String representation of the country code as defined in ISO 3166.
+         * @param countryCodeSource a String representation of country code source.
+         * @param instant a Instant representation of the time when the country code was created.
+         * @throws IllegalArgumentException if {@code countryCode} contains invalid country code.
+         */
         public CountryCodeInfo(
                 String countryCode, @CountryCodeSource String countryCodeSource, Instant instant) {
+            if (!isValidCountryCode(countryCode)) {
+                throw new IllegalArgumentException("Country code is invalid: " + countryCode);
+            }
+
             mCountryCode = countryCode;
             mSource = countryCodeSource;
             mUpdatedTimestamp = instant;
         }
 
+        /**
+         * Constructs a new {@code CountryCodeInfo} from the given country code, country code
+         * source. The updated timestamp of the country code will be set to the time when {@code
+         * CountryCodeInfo} was constructed.
+         *
+         * @param countryCode a String representation of the country code as defined in ISO 3166.
+         * @param countryCodeSource a String representation of country code source.
+         * @throws IllegalArgumentException if {@code countryCode} contains invalid country code.
+         */
         public CountryCodeInfo(String countryCode, @CountryCodeSource String countryCodeSource) {
             this(countryCode, countryCodeSource, Instant.now());
         }
@@ -188,7 +214,8 @@
             WifiManager wifiManager,
             Context context,
             TelephonyManager telephonyManager,
-            SubscriptionManager subscriptionManager) {
+            SubscriptionManager subscriptionManager,
+            @Nullable String oemCountryCode) {
         mLocationManager = locationManager;
         mThreadNetworkControllerService = threadNetworkControllerService;
         mGeocoder = geocoder;
@@ -197,6 +224,10 @@
         mContext = context;
         mTelephonyManager = telephonyManager;
         mSubscriptionManager = subscriptionManager;
+
+        if (oemCountryCode != null) {
+            mOemCountryCodeInfo = new CountryCodeInfo(oemCountryCode, COUNTRY_CODE_SOURCE_OEM);
+        }
     }
 
     public static ThreadNetworkCountryCode newInstance(
@@ -209,7 +240,8 @@
                 context.getSystemService(WifiManager.class),
                 context,
                 context.getSystemService(TelephonyManager.class),
-                context.getSystemService(SubscriptionManager.class));
+                context.getSystemService(SubscriptionManager.class),
+                ThreadNetworkProperties.country_code().orElse(null));
     }
 
     /** Sets up this country code module to listen to location country code changes. */
@@ -418,6 +450,9 @@
      *       number will be used.
      *   <li>5. Location country code - Country code retrieved from LocationManager passive location
      *       provider.
+     *   <li>6. OEM country code - Country code retrieved from the system property
+     *       `ro.boot.threadnetwork.country_code`.
+     *   <li>7. Default country code `WW`.
      * </ul>
      *
      * @return the selected country code information.
@@ -443,6 +478,10 @@
             return mLocationCountryCodeInfo;
         }
 
+        if (mOemCountryCodeInfo != null) {
+            return mOemCountryCodeInfo;
+        }
+
         return DEFAULT_COUNTRY_CODE_INFO;
     }
 
@@ -531,13 +570,14 @@
     /** Dumps the current state of this ThreadNetworkCountryCode object. */
     public synchronized void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
         pw.println("---- Dump of ThreadNetworkCountryCode begin ----");
-        pw.println("mOverrideCountryCodeInfo: " + mOverrideCountryCodeInfo);
+        pw.println("mOverrideCountryCodeInfo        : " + mOverrideCountryCodeInfo);
         pw.println("mTelephonyCountryCodeSlotInfoMap: " + mTelephonyCountryCodeSlotInfoMap);
-        pw.println("mTelephonyCountryCodeInfo: " + mTelephonyCountryCodeInfo);
-        pw.println("mWifiCountryCodeInfo: " + mWifiCountryCodeInfo);
-        pw.println("mTelephonyLastCountryCodeInfo: " + mTelephonyLastCountryCodeInfo);
-        pw.println("mLocationCountryCodeInfo: " + mLocationCountryCodeInfo);
-        pw.println("mCurrentCountryCodeInfo: " + mCurrentCountryCodeInfo);
+        pw.println("mTelephonyCountryCodeInfo       : " + mTelephonyCountryCodeInfo);
+        pw.println("mWifiCountryCodeInfo            : " + mWifiCountryCodeInfo);
+        pw.println("mTelephonyLastCountryCodeInfo   : " + mTelephonyLastCountryCodeInfo);
+        pw.println("mLocationCountryCodeInfo        : " + mLocationCountryCodeInfo);
+        pw.println("mOemCountryCodeInfo             : " + mOemCountryCodeInfo);
+        pw.println("mCurrentCountryCodeInfo         : " + mCurrentCountryCodeInfo);
         pw.println("---- Dump of ThreadNetworkCountryCode end ------");
     }
 }
diff --git a/thread/tests/unit/src/com/android/server/thread/ThreadNetworkCountryCodeTest.java b/thread/tests/unit/src/com/android/server/thread/ThreadNetworkCountryCodeTest.java
index 17cdd01..670449d 100644
--- a/thread/tests/unit/src/com/android/server/thread/ThreadNetworkCountryCodeTest.java
+++ b/thread/tests/unit/src/com/android/server/thread/ThreadNetworkCountryCodeTest.java
@@ -22,6 +22,7 @@
 
 import static com.google.common.truth.Truth.assertThat;
 
+import static org.junit.Assert.assertThrows;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.any;
 import static org.mockito.Mockito.anyDouble;
@@ -55,6 +56,7 @@
 import android.telephony.SubscriptionManager;
 import android.telephony.TelephonyManager;
 
+import androidx.annotation.Nullable;
 import androidx.test.filters.SmallTest;
 import androidx.test.runner.AndroidJUnit4;
 
@@ -70,6 +72,9 @@
 import org.mockito.MockitoAnnotations;
 import org.mockito.stubbing.Answer;
 
+import java.io.FileDescriptor;
+import java.io.PrintWriter;
+import java.io.StringWriter;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Locale;
@@ -80,6 +85,7 @@
 public class ThreadNetworkCountryCodeTest {
     private static final String TEST_COUNTRY_CODE_US = "US";
     private static final String TEST_COUNTRY_CODE_CN = "CN";
+    private static final String TEST_COUNTRY_CODE_INVALID = "INVALID";
     private static final int TEST_SIM_SLOT_INDEX_0 = 0;
     private static final int TEST_SIM_SLOT_INDEX_1 = 1;
 
@@ -144,16 +150,20 @@
                 .when(mThreadNetworkControllerService)
                 .setCountryCode(any(), any(IOperationReceiver.class));
 
-        mThreadNetworkCountryCode =
-                new ThreadNetworkCountryCode(
-                        mLocationManager,
-                        mThreadNetworkControllerService,
-                        mGeocoder,
-                        mConnectivityResources,
-                        mWifiManager,
-                        mContext,
-                        mTelephonyManager,
-                        mSubscriptionManager);
+        mThreadNetworkCountryCode = newCountryCodeWithOemSource(null);
+    }
+
+    private ThreadNetworkCountryCode newCountryCodeWithOemSource(@Nullable String oemCountryCode) {
+        return new ThreadNetworkCountryCode(
+                mLocationManager,
+                mThreadNetworkControllerService,
+                mGeocoder,
+                mConnectivityResources,
+                mWifiManager,
+                mContext,
+                mTelephonyManager,
+                mSubscriptionManager,
+                oemCountryCode);
     }
 
     private static Address newAddress(String countryCode) {
@@ -163,6 +173,13 @@
     }
 
     @Test
+    public void threadNetworkCountryCode_invalidOemCountryCode_illegalArgumentExceptionIsThrown() {
+        assertThrows(
+                IllegalArgumentException.class,
+                () -> newCountryCodeWithOemSource(TEST_COUNTRY_CODE_INVALID));
+    }
+
+    @Test
     public void initialize_defaultCountryCodeIsUsed() {
         mThreadNetworkCountryCode.initialize();
 
@@ -170,6 +187,15 @@
     }
 
     @Test
+    public void initialize_oemCountryCodeAvailable_oemCountryCodeIsUsed() {
+        mThreadNetworkCountryCode = newCountryCodeWithOemSource(TEST_COUNTRY_CODE_US);
+
+        mThreadNetworkCountryCode.initialize();
+
+        assertThat(mThreadNetworkCountryCode.getCountryCode()).isEqualTo(TEST_COUNTRY_CODE_US);
+    }
+
+    @Test
     public void initialize_locationUseIsDisabled_locationFunctionIsNotCalled() {
         when(mResources.getBoolean(R.bool.config_thread_location_use_for_country_code_enabled))
                 .thenReturn(false);
@@ -406,4 +432,22 @@
                 .setCountryCode(eq(TEST_COUNTRY_CODE_CN), mOperationReceiverCaptor.capture());
         assertThat(mThreadNetworkCountryCode.getCountryCode()).isEqualTo(DEFAULT_COUNTRY_CODE);
     }
+
+    @Test
+    public void dump_allCountryCodeInfoAreDumped() {
+        StringWriter stringWriter = new StringWriter();
+        PrintWriter printWriter = new PrintWriter(stringWriter);
+
+        mThreadNetworkCountryCode.dump(new FileDescriptor(), printWriter, null);
+        String outputString = stringWriter.toString();
+
+        assertThat(outputString).contains("mOverrideCountryCodeInfo");
+        assertThat(outputString).contains("mTelephonyCountryCodeSlotInfoMap");
+        assertThat(outputString).contains("mTelephonyCountryCodeInfo");
+        assertThat(outputString).contains("mWifiCountryCodeInfo");
+        assertThat(outputString).contains("mTelephonyLastCountryCodeInfo");
+        assertThat(outputString).contains("mLocationCountryCodeInfo");
+        assertThat(outputString).contains("mOemCountryCodeInfo");
+        assertThat(outputString).contains("mCurrentCountryCodeInfo");
+    }
 }