Add --root functionality for secure displays above A11

app/src/cli.c

@@ -114,6 +114,7 @@ enum {
     OPT_NO_VD_SYSTEM_DECORATIONS,
     OPT_NO_VD_DESTROY_CONTENT,
     OPT_DISPLAY_IME_POLICY,
+    OPT_ROOT,
 };
 
 struct sc_option {
@@ -841,6 +842,15 @@ static const struct sc_option options[] = {
                 "fails on the device. This option makes scrcpy fail if audio "
                 "is enabled but does not work."
     },
+    {
+        .longopt_id = OPT_ROOT,
+        .longopt = "root",
+        .text = "By default, scrcpy simply uses the ADB shell user context to "
+                "execute the server on the device. This will instruct scrcpy "
+                "use the `su` command to run the server as the system user in "
+                "order to retain the ability to create a secure display. This "
+                "allows apps that use `FLAG_SECURE` to be mirrored to your PC."
+    },
     {
         // deprecated
         .longopt_id = OPT_ROTATION,
@@ -2724,6 +2734,43 @@ parse_args_with_getopt(struct scrcpy_cli_args *args, int argc, char *argv[],
             case OPT_REQUIRE_AUDIO:
                 opts->require_audio = true;
                 break;
+            case OPT_ROOT:
+                opts->root = true;
+
+                // 1. Check if 'su 1000 -c true' works
+                int su_status = system("adb shell su 1000 -c true >/dev/null 2>&1");
+                bool can_use_root = (su_status == 0);
+
+                // 2. Check if secure display is possible under shell
+                int sdk_version = 0;
+                char codename[16] = {0};
+
+                FILE *fp = popen("adb shell getprop ro.build.version.sdk", "r");
+                if (fp) {
+                    fscanf(fp, "%d", &sdk_version);
+                    pclose(fp);
+                }
+
+                fp = popen("adb shell getprop ro.build.version.codename", "r");
+                if (fp) {
+                    fscanf(fp, "%15s", codename);
+                    pclose(fp);
+                }
+
+                // 3. Determine secure display capability as upstream JAR does
+                bool shell_can_create_secure_display = (sdk_version < 30 || (sdk_version == 30 && strcmp(codename, "S") != 0));
+
+                // 4. Compute whether root should actually be enabled
+                bool needs_root_for_secure_display = !shell_can_create_secure_display;
+                opts->root_enabled = opts->root && can_use_root && needs_root_for_secure_display;
+
+                // 5. Provide user feedback
+                if (opts->root && !can_use_root && needs_root_for_secure_display) {
+                    fprintf(stderr,
+                            "WARNING: --root requested but 'su 1000' failed and secure display is unavailable on Android 12+.\n"
+                            "Secure content will not be mirrored.\n");
+                }
+                break;
             case OPT_AUDIO_BUFFER:
                 if (!parse_buffering_time(optarg, &opts->audio_buffer)) {
                     return false;

app/src/options.c

@@ -113,6 +113,8 @@ const struct scrcpy_options scrcpy_options_default = {
     .angle = NULL,
     .vd_destroy_content = true,
     .vd_system_decorations = true,
+    .root = false,
+    .root_enabled = false,
 };
 
 enum sc_orientation

app/src/options.h

@@ -327,6 +327,8 @@ struct scrcpy_options {
     const char *start_app;
     bool vd_destroy_content;
     bool vd_system_decorations;
+    bool root;
+    bool root_enabled;
 };
 
 extern const struct scrcpy_options scrcpy_options_default;

app/src/scrcpy.c

@@ -473,6 +473,7 @@ scrcpy(struct scrcpy_options *options) {
         .camera_high_speed = options->camera_high_speed,
         .vd_destroy_content = options->vd_destroy_content,
         .vd_system_decorations = options->vd_system_decorations,
+        .root = options->root,
         .list = options->list,
     };
 

app/src/server.c

@@ -215,6 +215,11 @@ execute_server(struct sc_server *server,
     cmd[count++] = "-s";
     cmd[count++] = serial;
     cmd[count++] = "shell";
+    if (params->root_enabled) {
+        cmd[count++] = "su";
+        cmd[count++] = "1000";
+        cmd[count++] = "-c";
+    }
     cmd[count++] = "CLASSPATH=" SC_DEVICE_SERVER_PATH;
     cmd[count++] = "app_process";
 

app/src/server.h

@@ -70,6 +70,8 @@ struct sc_server_params {
     bool camera_high_speed;
     bool vd_destroy_content;
     bool vd_system_decorations;
+    bool root;
+    bool root_enabled;
     uint8_t list;
 };
 

server/src/main/java/com/genymobile/scrcpy/FakeContext.java

@@ -16,7 +16,7 @@
 
 public final class FakeContext extends ContextWrapper {
 
-    public static final String PACKAGE_NAME = "com.android.shell";
+    public static final String PACKAGE_NAME = Process.myUid() == 1000 ? "android" : "com.android.shell";
     public static final int ROOT_UID = 0; // Like android.os.Process.ROOT_UID, but before API 29
 
     private static final FakeContext INSTANCE = new FakeContext();

server/src/main/java/com/genymobile/scrcpy/util/Settings.java

@@ -3,6 +3,8 @@
 import com.genymobile.scrcpy.wrappers.ContentProvider;
 import com.genymobile.scrcpy.wrappers.ServiceManager;
 
+import android.os.Process;
+
 public final class Settings {
 
     public static final String TABLE_SYSTEM = ContentProvider.TABLE_SYSTEM;
@@ -16,23 +18,43 @@ private Settings() {
     public static String getValue(String table, String key) throws SettingsException {
         try (ContentProvider provider = ServiceManager.getActivityManager().createSettingsProvider()) {
             return provider.getValue(table, key);
+        } catch (Exception e) {
+            throw new SettingsException("getValue", table, key, null, e);
         }
     }
 
     public static void putValue(String table, String key, String value) throws SettingsException {
-        try (ContentProvider provider = ServiceManager.getActivityManager().createSettingsProvider()) {
-            provider.putValue(table, key, value);
-        }
+        if (Process.myUid() == 1000) {
+            // UID_SYSTEM path: fallback to 'su -c settings put ...'
+            try {
+                String cmd = "settings put " + table + " " + key + " " + value;
+                String[] command = { "su", "-c", cmd };
 
-    }
+                java.lang.Process proc = Runtime.getRuntime().exec(command);
+                int exit = proc.waitFor();
 
-    public static String getAndPutValue(String table, String key, String value) throws SettingsException {
-        try (ContentProvider provider = ServiceManager.getActivityManager().createSettingsProvider()) {
-            String oldValue = provider.getValue(table, key);
-            if (!value.equals(oldValue)) {
+                if (exit != 0) {
+                    throw new SettingsException("putValue", table, key, value, null);
+                }
+
+            } catch (Exception e) {
+                throw new SettingsException("putValue", table, key, value, e);
+            }
+        } else {
+            // AID_SHELL path: use standard provider
+            try (ContentProvider provider = ServiceManager.getActivityManager().createSettingsProvider()) {
                 provider.putValue(table, key, value);
+            } catch (Exception e) {
+                throw new SettingsException("putValue", table, key, value, e);
             }
-            return oldValue;
         }
     }
+
+    public static String getAndPutValue(String table, String key, String value) throws SettingsException {
+        String oldValue = getValue(table, key);
+        if (!value.equals(oldValue)) {
+            putValue(table, key, value);
+        }
+        return oldValue;
+    }
 }

server/src/main/java/com/genymobile/scrcpy/video/ScreenCapture.java

@@ -21,6 +21,7 @@
 import android.hardware.display.VirtualDisplay;
 import android.os.Build;
 import android.os.IBinder;
+import android.os.Process;
 import android.view.Surface;
 
 import java.io.IOException;
@@ -196,8 +197,8 @@ public boolean setMaxSize(int newMaxSize) {
     private static IBinder createDisplay() throws Exception {
         // Since Android 12 (preview), secure displays could not be created with shell permissions anymore.
         // On Android 12 preview, SDK_INT is still R (not S), but CODENAME is "S".
-        boolean secure = Build.VERSION.SDK_INT < AndroidVersions.API_30_ANDROID_11 || (Build.VERSION.SDK_INT == AndroidVersions.API_30_ANDROID_11
-                && !"S".equals(Build.VERSION.CODENAME));
+        boolean secure = (Build.VERSION.SDK_INT < AndroidVersions.API_30_ANDROID_11 || (Build.VERSION.SDK_INT == AndroidVersions.API_30_ANDROID_11
+                && !"S".equals(Build.VERSION.CODENAME))) || android.os.Process.myUid() == 1000;
         return SurfaceControl.createDisplay("scrcpy", secure);
     }