1 files changed, 95 insertions, 0 deletions
diff --git a/core/java/android/os/GraphicsEnvironment.java b/core/java/android/os/GraphicsEnvironment.java
new file mode 100644
index 000000000000..4b130ed1adc8
--- /dev/null
+++ b/core/java/android/os/GraphicsEnvironment.java
@@ -0,0 +1,95 @@
+/*
+ * Copyright 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.os;
+
+import android.content.Context;
+import android.content.pm.ApplicationInfo;
+import android.content.pm.PackageManager;
+import android.os.SystemProperties;
+import android.util.Log;
+
+import dalvik.system.VMRuntime;
+
+import java.io.File;
+
+/** @hide */
+public final class GraphicsEnvironment {
+
+    private static final boolean DEBUG = false;
+    private static final String TAG = "GraphicsEnvironment";
+    private static final String PROPERTY_GFX_DRIVER = "ro.gfx.driver.0";
+
+    public static void setupGraphicsEnvironment(Context context) {
+        String driverPackageName = SystemProperties.get(PROPERTY_GFX_DRIVER);
+        if (driverPackageName == null || driverPackageName.isEmpty()) {
+            return;
+        }
+        // To minimize risk of driver updates crippling the device beyond user repair, never use an
+        // updated driver for privileged or non-updated system apps. Presumably pre-installed apps
+        // were tested thoroughly with the pre-installed driver.
+        ApplicationInfo ai = context.getApplicationInfo();
+        if (ai.isPrivilegedApp() || (ai.isSystemApp() && !ai.isUpdatedSystemApp())) {
+            if (DEBUG) Log.v(TAG, "ignoring driver package for privileged/non-updated system app");
+            return;
+        }
+        ApplicationInfo driverInfo;
+        try {
+            driverInfo = context.getPackageManager().getApplicationInfo(driverPackageName,
+                    PackageManager.MATCH_SYSTEM_ONLY);
+        } catch (PackageManager.NameNotFoundException e) {
+            Log.w(TAG, "driver package '" + driverPackageName + "' not installed");
+            return;
+        }
+        String abi = chooseAbi(driverInfo);
+        if (abi == null) {
+            if (DEBUG) {
+                // This is the normal case for the pre-installed empty driver package, don't spam
+                if (driverInfo.isUpdatedSystemApp()) {
+                    Log.w(TAG, "updated driver package has no compatible native libraries");
+                }
+            }
+            return;
+        }
+
+        StringBuilder sb = new StringBuilder();
+        sb.append(driverInfo.nativeLibraryDir)
+          .append(File.pathSeparator);
+        sb.append(driverInfo.sourceDir)
+          .append("!/lib/")
+          .append(abi);
+        String paths = sb.toString();
+
+        if (DEBUG) Log.v(TAG, "gfx driver package libs: " + paths);
+        setDriverPath(paths);
+    }
+
+    private static String chooseAbi(ApplicationInfo ai) {
+        String isa = VMRuntime.getCurrentInstructionSet();
+        if (ai.primaryCpuAbi != null &&
+                isa.equals(VMRuntime.getInstructionSet(ai.primaryCpuAbi))) {
+            return ai.primaryCpuAbi;
+        }
+        if (ai.secondaryCpuAbi != null &&
+                isa.equals(VMRuntime.getInstructionSet(ai.secondaryCpuAbi))) {
+            return ai.secondaryCpuAbi;
+        }
+        return null;
+    }
+
+    private static native void setDriverPath(String path);
+
+}