android 定制mtp连接外设的设备名称

软件平台：Android11

硬件平台：QCS6125

    需求：同一套代码基线支持多个产品型号，如S2N、S2C、E1等，但是编译的时候model属性字段在build目录就是配置好不可再更改的，如何动态的实现展示不同的mtp设备名称呢？

主要涉及两个部分的代码变更：

1、framework目录相关改动：

diff --git a/media/java/android/mtp/MtpDatabase.java b/media/java/android/mtp/MtpDatabase.java
index 798bf6e2f8e..a63e4229317 100755
--- a/media/java/android/mtp/MtpDatabase.java
+++ b/media/java/android/mtp/MtpDatabase.java
@@ -665,13 +665,28 @@ public class MtpDatabase implements AutoCloseable {
         }
     }
 
+    private String getDeviceName() {
+        String devDefName = "S2";
+        String devS2N = "S2N";
+        String getName = null;
+
+        getName = SystemProperties.get("ro.product.yfdsubmodel");
+        if (null == getName) return devDefName;
+
+        if (getName.contains("S2N"))
+            return devS2N;
+        else
+            return devDefName;
+    }
+
     @VisibleForNative
     private int getDeviceProperty(int property, long[] outIntValue, char[] outStringValue) {
         switch (property) {
             case MtpConstants.DEVICE_PROPERTY_SYNCHRONIZATION_PARTNER:
             case MtpConstants.DEVICE_PROPERTY_DEVICE_FRIENDLY_NAME:
                 // writable string properties kept in shared preferences
-                String value = mDeviceProperties.getString(Integer.toString(property), "");
+                //String value = mDeviceProperties.getString(Integer.toString(property), "");
+                String value = getDeviceName();
                 int length = value.length();
                 if (length > 255) {
                     length = 255;

    上述submodel属性是系统首次启动init根据内核硬件检测初始化的boardid值去初始化的，用于区分细微硬件差别。

2、packages/services/Mtp目录改动：

diff --git a/src/com/android/mtp/MtpService.java b/src/com/android/mtp/MtpService.java
index 8520b9e..1fa1aaa 100644
--- a/src/com/android/mtp/MtpService.java
+++ b/src/com/android/mtp/MtpService.java
@@ -32,6 +32,7 @@ import android.os.ParcelFileDescriptor;
 import android.os.RemoteException;
 import android.os.ServiceManager;
 import android.os.UserHandle;
+import android.os.SystemProperties;
 import android.os.storage.StorageEventListener;
 import android.os.storage.StorageManager;
 import android.os.storage.StorageVolume;
@@ -165,6 +166,27 @@ public class MtpService extends Service {
         return START_REDELIVER_INTENT;
     }
 
+    private String getDeviceName() {
+        String devDefName = "S2";
+        String getName = null;
+
+        getName = SystemProperties.get("ro.product.yfdsubmodel");
+        if (null == getName) return devDefName;
+
+        if (getName.contains("S2N"))
+            return "S2N";
+        else if (getName.contains("S2C"))
+            return "S2C";
+        else if (getName.contains("S2A"))
+            return "S2A";
+        else if (getName.contains("S3"))
+            return "S3";
+        else if (getName.contains("E1"))
+            return "E1";
+        else
+            return devDefName;
+    }
+
     private synchronized void startServer(StorageVolume primary, String[] subdirs) {
         if (!(UserHandle.myUserId() == ActivityManager.getCurrentUser())) {
             return;
@@ -200,10 +222,14 @@ public class MtpService extends Service {
                 fd = controlFd.getFileDescriptor();
             }
 
+            //final MtpServer server =
+            //        new MtpServer(database, fd, mPtpMode,
+            //                new OnServerTerminated(), Build.MANUFACTURER,
+            //                Build.MODEL, "1.0");
             final MtpServer server =
                     new MtpServer(database, fd, mPtpMode,
                             new OnServerTerminated(), Build.MANUFACTURER,
-                            Build.MODEL, "1.0");
+                            getDeviceName(), "1.0");
             database.setServer(server);
             sServerHolder = new ServerHolder(server, database);

    之所以需要此改动，是因为我本地一台windows一台mac，改动第一条，在win生效，但是在mac没效果，添加第二条改动后，mac显示也正常。