Overview

Scope of application

RK3399 Android7.1 Industry
RK3399 Android10
RK356X Android11
RK3588 Android12

For other Android versions, it is available for reference.

Modification method

For Android system customization, there are generally Temporary modification methods and Code modification methods.

Temporary modification method：Generally, the device can be operated through the debug serial port or ADB.
Code modification method：After modifying the code, you need to perform SDK compilation and firmware flashing.

Among them, SDK compilation or firmware flashing refer to WiKi tutorial。

Glossary

CPU_TYPE：Indicates the main control chip, such as rk3288, rk3399, rk3399pro, rk356x, rk3588
PRODUCT_TYPE：Indicates the product type, such as rk3399_firefly, rk3399_firefly_aio, rk3399_firefly_aioc_ai

For the customized content of the system, there will be some differences in Android12, Android11, Android10.0 and Android7.1 Industry. This part of the content will be distinguished, and the undifferentiated content indicates compatibility.

Boot logo animation modification

The first stage

Code modification method

Prepare the logo
- Make a new logo.bmp
  - The image attributes are the same as the default logo.bmp, otherwise an upside-down exception will occur
  - Both width and height are even numbers
Replace logo
- Replace kernel/logo.bmp

Second stage

Temporary modification method

Prepare bootanimation.zip
- Prepare png file
  - Both width and height are even numbers
- Prepare desc.txt file, such as
```
800 1280 30
p 0 0 part0
```
  - 800 1280 30Meaning: the first two numbers represent the pixel width and height of the picture, 30 represents the number of frames, which is the number of pictures played in 1 second
  - p 0 0 part0Meaning: p stands for flag bit, 0 stands for infinite loop, 0 stands for the interval time between stages is 0, part0 stands for the corresponding folder
  - desc.txt text format: Unix+UTF-8
- Make bootanimation.zip
  - Compressed into a zip file in storage method

Push bootanimation.zip

adb shell setprop persist.sys.root_access 3
adb root
adb remount
adb push bootanimation.zip system/media/bootanimation.zip
adb shell reboot

Code modification method

Prepare bootanimation.zip
- Put the prepared bootanimation.zip into the device/rockchip/CPU_TYPE/ directory

In the device/rockchip/CPU_TYPE/device.mk file, add the following content:

PRODUCT_COPY_FILES += \
       device/rockchip/CPU_TYPE/bootanimation.zip:/system/media/bootanimation.zip

Default screen orientation modification

Temporary modification method

System readable and writable

adb shell setprop persist.sys.root_access 3
adb root
adb remount

Modify or add attribute values
- Android7.1
  - In the /system/build.prop file, modify or add the value of ro.sf.hwrotation
    - 0：Horizontal screen
    - 90：Portrait
    - 180：Reverse landscape
    - 270：Reverse portrait
- Android10 and above
  - In the vendor/build.prop file, modify or add the value of ro.surface_flinger.primary_display_orientation
    - ORIENTATION_0：Horizontal screen
    - ORIENTATION_90：Portrait
    - ORIENTATION_180：Reverse landscape
    - ORIENTATION_270：Reverse portrait
  - Android14 also needs to add the following properties in the vendor/build.prop file debug.sf.ignore_hwc_physical_display_orientation=true
System restart
```
adb shell reboot
```

Code modification method

Android 7.1:

In the file device/rockchip/CPU_TYPE/PRODUCT_TYPE/system.prop, modify the value of ro.sf.hwrotation
Android10 and above:

In the file device/rockchip/CPU_TYPE/BoardConfig.mk, modify the value of SF_PRIMARY_DISPLAY_ORIENTATION
- 0：Horizontal screen
- 90：Portrait
- 180：Reverse landscape
- 270：Reverse portrait

Delete build.prop in the out directory

rm out/target/product/PRODUCT_TYPE/obj/ETC/system_build_prop_intermediates/build.prop

Hide the status bar by default

Temporary modification method

In the Settings, just enable the option.

Settings-->Display-->Always hide the status bar

Code modification method

The revised content is as follows

diff --git a/frameworks/base/packages/SettingsProvider/res/values/custom_defaults.xml b/frameworks/base/packages/SettingsProvider/res/values/custom_defaults.xml
index ba87da7ec4..e32c9699f9 100644
--- a/frameworks/base/packages/SettingsProvider/res/values/custom_defaults.xml
+++ b/frameworks/base/packages/SettingsProvider/res/values/custom_defaults.xml
@@ -12,7 +12,7 @@
     <!-- should show the hidebar button default -->
     <bool name="def_hidebar_button_show">true</bool>
     <!-- always hide statusbar -->
-    <bool name="def_always_hide_bar">false</bool>
+    <bool name="def_always_hide_bar">true</bool>

     <!-- will set DEFAULT_LAUNCHER in frist boot -->
     <string name="def_default_launcher" translatable="false"></string>

Several ways of setting built-in APP

Code modification method

App folders can be added under the vendor directory

Not uninstallable

Refer to vendor/firefly/fireflyapi

Contents in Android.mk

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := firefly_sdkapi_demo
LOCAL_MODULE_CLASS := APPS
LOCAL_MODULE_TAGS := optional
LOCAL_BUILT_MODULE_STEM := package.apk
LOCAL_MODULE_SUFFIX := $(COMMON_ANDROID_PACKAGE_SUFFIX)
#LOCAL_PRIVILEGED_MODULE :=
LOCAL_CERTIFICATE := platform
#LOCAL_OVERRIDES_PACKAGES := 
LOCAL_SRC_FILES := $(LOCAL_MODULE).apk
#LOCAL_REQUIRED_MODULES :=
#LOCAL_PREBUILT_JNI_LIBS :=
include $(BUILD_PREBUILT)

LOCAL_CERTIFICATE := platform Meaning: APK signature uses system signature
LOCAL_PRIVILEGED_MODULE If not set or set to false, the installation location is /system/app

Contents in fireflyapi.mk

PRODUCT_PACKAGES += \
   	firefly_sdkapi_demo 

PRODUCT_COPY_FILES += \
       vendor/firefly/fireflyapi/fireflyapi:system/bin/fireflyapi \
       vendor/firefly/fireflyapi/fireflyapi.jar:system/framework/fireflyapi.jar

Uninstallable

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := FDeviceTest
LOCAL_MODULE_CLASS := APPS
LOCAL_MODULE_TAGS := optional
LOCAL_BUILT_MODULE_STEM := package.apk
LOCAL_DEX_PREOPT := nostripping
LOCAL_MODULE_SUFFIX := $(COMMON_ANDROID_PACKAGE_SUFFIX)
LOCAL_PRIVILEGED_MODULE := true
LOCAL_CERTIFICATE := PRESIGNED
LOCAL_OVERRIDES_PACKAGES := DeviceTest
LOCAL_SRC_FILES := $(LOCAL_MODULE).apk
LOCAL_MULTILIB := 32
#LOCAL_REQUIRED_MODULES :=
JNI_LIBS :=
$(foreach FILE,$(shell find $(LOCAL_PATH)/lib/ -name *.so), $(eval JNI_LIBS += $(FILE)))
LOCAL_PREBUILT_JNI_LIBS := $(subst $(LOCAL_PATH),,$(JNI_LIBS))

include $(BUILD_PREBUILT)

mkdir device/rockchip/CPU_TYPE/PRODUCT_TYPE/preinstall_del
copy apk to device/rockchip/CPU_TYPE/PRODUCT_TYPE/preinstall_del
build android

Setting of built-in default input method

Code modification method

Get the input method package name

adb shell settings get secure enabled_input_methods
com.android.inputmethod.latin/.LatinIME:com.iflytek.inputmethod.google/com.iflytek.inputmethod.FlyIME:com.google.android.inputmethod.pinyin/.PinyinIME
adb shell settings get secure default_input_method
com.iflytek.inputmethod.google/com.iflytek.inputmethod.FlyIME

Modify the code as follows

diff --git a/frameworks/base/packages/SettingsProvider/res/values/custom_defaults.xml b/frameworks/base/packages/SettingsProvider/res/values/custom_defaults.xml
index ba87da7ec4..7ed79b4c15 100644
--- a/frameworks/base/packages/SettingsProvider/res/values/custom_defaults.xml
+++ b/frameworks/base/packages/SettingsProvider/res/values/custom_defaults.xml
@@ -19,4 +19,7 @@

     <!-- if 1 ,reboot will reset DEFAULT_LAUNCHER -->
     <bool name="def_lock_default_launcher">false</bool>
+
+       <string name="enabled_input_methods" translatable="false">com.android.inputmethod.latin/.LatinIME:com.iflytek.inputmethod.google/com.iflytek.inputmethod.FlyIME:com.google.android.inputmethod.pinyin/.PinyinIME</string>
+       <string name="def_input_method" translatable="false">com.iflytek.inputmethod.google/com.iflytek.inputmethod.FlyIME</string>
 </resources>

diff --git a/frameworks/base/packages/SettingsProvider/src/com/android/providers/settings/DatabaseHelper.java b/frameworks/base/packages/SettingsProvider/src/com/android/providers/settings/DatabaseHelper.java
index cac5f800bd..f705a895b4 100644
--- a/frameworks/base/packages/SettingsProvider/src/com/android/providers/settings/DatabaseHelper.java
+++ b/frameworks/base/packages/SettingsProvider/src/com/android/providers/settings/DatabaseHelper.java
@@ -2474,6 +2474,11 @@ class DatabaseHelper extends SQLiteOpenHelper {
             stmt = db.compileStatement("INSERT OR IGNORE INTO secure(name,value)"
                     + " VALUES(?,?);");

+                       loadStringSetting(stmt, Settings.Secure.ENABLED_INPUT_METHODS,
+                                       R.string.enabled_input_methods);
+                       loadStringSetting(stmt, Settings.Secure.DEFAULT_INPUT_METHOD,
+                                       R.string.def_input_method);
+
             loadStringSetting(stmt, Settings.Secure.LOCATION_PROVIDERS_ALLOWED,
                     R.string.def_location_providers_allowed);

Delete built-in apps

Temporary modification method

adb shell setprop persist.sys.root_access 3
adb root
adb remount
adb shell rm -r system/app/APK_NAME/
adb shell reboot

adb shell setprop persist.sys.root_access 3
adb root
adb remount
adb shell rm -r system/priv-app/APK_NAME/
adb shell reboot

Code modification method

If the application has source code, comment out the include $(BUILD_PACKAGE) in the Android.mk file of the application source code
If the application is an APK file and has Android.mk, comment out include $(BUILD_PREBUILT) in the Android.mk file

Startup application

Code modification method

Non-launcher

Add the following content to the AndroidManifest.xml in the application source code

package="com.example.testfile"
android:sharedUserId="android.uid.system">

<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />

<receiver android:name="com.example.testfile.BootBroadcastReceiver" >
    <intent-filter>
        <action android:name="android.intent.action.BOOT_COMPLETED" />
        <category android:name="android.intent.category.LAUNCHER" />
   </intent-filter>
</receiver>

Add the code for broadcast reception BootBroadcastReceiver.java, such as

package com.example.testfile;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.util.Log;
import android.widget.Toast;

public class BootBroadcastReceiver extends BroadcastReceiver{
    private static final String TAG = "sjft";

    public static final String EXTRA_VOLUME_STATE =
            "android.os.storage.extra.VOLUME_STATE";

    public static final int STATE_UNMOUNTED = 0;
    public static final int STATE_CHECKING = 1;
    public static final int STATE_MOUNTED = 2;
    public static final int STATE_MOUNTED_READ_ONLY = 3;
    public static final int STATE_FORMATTING = 4;
    public static final int STATE_EJECTING = 5;
    public static final int STATE_UNMOUNTABLE = 6;
    public static final int STATE_REMOVED = 7;
    public static final int STATE_BAD_REMOVAL = 8;

    @Override
    public void onReceive(Context context, Intent intent) {
        // TODO Auto-generated method stub
        String action = intent.getAction();
        if (action.equals("android.intent.action.PACKAGE_REPLACED")){
            String packageName = intent.getData().getSchemeSpecificPart();
            Log.v(TAG,"BootBroadcastReceiver packageName:"+packageName);
            if(context.getPackageName().equals(packageName)){
                Intent launchIntent = new Intent(context, MainActivity.class);//Restart the app 
                //If you don’t want to write the startup Activity, you can also get the default startup Activity by the following method 
                //Intent launchIntent = context.getPackageManager().getLaunchIntentForPackage(packageName);
                launchIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                context.startActivity(launchIntent);
            }
        } else if (action.equals("android.intent.action.BOOT_COMPLETED")){
            String packageName = intent.getData().getSchemeSpecificPart();
            Log.v(TAG,"BootBroadcastReceiver packageName:"+packageName);
            if(context.getPackageName().equals(packageName)){
                Intent launchIntent = new Intent(context, MainActivity.class);//Restart the app 
                //If you don’t want to write the startup Activity, you can also get the default startup Activity by the following method 
                //Intent launchIntent = context.getPackageManager().getLaunchIntentForPackage(packageName);
                launchIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                context.startActivity(launchIntent);
            }
        } 
    }
}

app system signature (signature file)
start app once

Launcher

Delete or not compile the Launcher application in the SDK

Add the following content to the first activity started in AndroidManifest.xml in the application source code

<intent-filter>
    <action android:name="android.intent.action.MAIN" />
    <category android:name="android.intent.category.LAUNCHER" />
</intent-filter>

Modification of the default language

The language support list can be viewed in build/target/product/languages_full.mk.

Temporary modification method

System readable and writable

adb shell setprop persist.sys.root_access 3
adb root
adb remount

Modify the value of ro.product.locale in the /system/build.prop file (Android10 and above: /vendor/build.prop)
- en-US: English
- zh-CN: Chinese
System restart
```
adb shell reboot
```

Code modification method

Modify the value of PRODUCT_LOCALES in build/target/product/full_base.mk
- Chinese
```
PRODUCT_LOCALES := zh_CN
```

Delete build.prop in the out directory

rm out/target/product/PRODUCT_TYPE/obj/ETC/system_build_prop_intermediates/build.prop

Modification of the default time zone

The time zone support list can be viewed in frameworks/base/packages/SettingsLib/res/xml/timezones.xml.

Temporary modification method

System readable and writable

adb shell setprop persist.sys.root_access 3
adb root
adb remount

Modify the value of persist.sys.timezone in the /system/build.prop file (Android10 and above: /vendor/build.prop)
- Asia/Shanghai：UTC+8
System restart
```
adb shell reboot
```

Code modification method

Android7.1/Android10
- In the file device/rockchip/CPU_TYPE/PRODUCT_TYPE/system.prop, modify the value of persist.sys.timezone
  - Asia/Shanghai：UTC+8
Android11 and above
- Add the following content in the device/rockchip/CPU_TYPE/PRODUCT_TYPE/PRODUCT_TYPE.mk file:
```
PRODUCT_PROPERTY_OVERRIDES += persist.sys.timezone=Asia/Shanghai
```

Delete build.prop in the out directory

rm out/target/product/PRODUCT_TYPE/obj/ETC/system_build_prop_intermediates/build.prop

Default ROOT

Temporary modification method

adb shell setprop persist.sys.root_access 3

Code modification method

Android7.1/Android10.0
- In the device/rockchip/CPU_TYPE/PRODUCT_TYPE/system.prop file, add the following content:
```
persist.sys.root_access=3
```
Android11 and above
- Add the following content in the device/rockchip/CPU_TYPE/PRODUCT_TYPE/PRODUCT_TYPE.mk file:
```
PRODUCT_PROPERTY_OVERRIDES += persist.sys.root_access=3
```

Delete build.prop in the out directory

rm out/target/product/PRODUCT_TYPE/obj/ETC/system_build_prop_intermediates/build.prop

The default system time is 24 hours

Code modification method

diff --git a/frameworks/base/packages/SettingsProvider/res/values/defaults.xml b/frameworks/base/packages/SettingsProvider/res/values/defaults.xml
index f95ecc6535..06055dba7b 100644
--- a/frameworks/base/packages/SettingsProvider/res/values/defaults.xml
+++ b/frameworks/base/packages/SettingsProvider/res/values/defaults.xml
@@ -244,4 +244,6 @@
 
     <!-- should show the screenshot button default -->
     <integer name="def_screenshot_button_show">0</integer>
+<!-- value 12/24/null corresponds to setting 12/24/auto -->
+    <string name="def_time_12_24" translatable="false">24</string>
 </resources>
diff --git a/frameworks/base/packages/SettingsProvider/src/com/android/providers/settings/DatabaseHelper.java b/frameworks/base/packages/SettingsProvider/src/com/android/providers/settings/DatabaseHelper.java
index b3ff9d08a8..ebdd5d3637 100644
--- a/frameworks/base/packages/SettingsProvider/src/com/android/providers/settings/DatabaseHelper.java
+++ b/frameworks/base/packages/SettingsProvider/src/com/android/providers/settings/DatabaseHelper.java
@@ -2261,6 +2261,9 @@ class DatabaseHelper extends SQLiteOpenHelper {
    private void loadSystemSettings(SQLiteDatabase db) {
                                     ......
+            
+            loadStringSetting(stmt, Settings.System.TIME_12_24,
+                    R.string.def_time_12_24);

Open network ADB by default

Temporary modification method

Way one

Android7.1

adb shell setprop persist.internet.adb.enable 1

Android10/Android11/Android12

adb shell setprop persist.internet_adb_enable 1

Way two

Open "Developer Options"
Open ADB over network

Settings-->Developer options-->ADB over network

Code modification method

Android7.1/Android10
- In the device/rockchip/CPU_TYPE/PRODUCT_TYPE/system.prop file, add the following content:
```
persist.internet.adb.enable=1
```
Android10
- In the device/rockchip/CPU_TYPE/PRODUCT_TYPE/system.prop file, add the following content:
```
persist.internet_adb_enable=1
```
Android11/Android12
- In the device/rockchip/CPU_TYPE/PRODUCT_TYPE/PRODUCT_TYPE.mk file, add the following content:
```
PRODUCT_PROPERTY_OVERRIDES += persist.internet_adb_enable=1
```

Delete build.prop in the out directory

rm out/target/product/PRODUCT_TYPE/obj/ETC/system_build_prop_intermediates/build.prop

The default setting of OTG USB3.0 is devices mode

Temporary modification method

adb shell setprop persist.usb.mode 2

Code modification method

Android7.1/Android10
- In the device/rockchip/CPU_TYPE/PRODUCT_TYPE/system.prop file, add the following content:
```
persist.usb.mode=2
```
Android11/Android12
- In the device/rockchip/CPU_TYPE/PRODUCT_TYPE/PRODUCT_TYPE.mk file, add the following content:
```
PRODUCT_PROPERTY_OVERRIDES += persist.usb.mode=otg
```

Delete build.prop in the out directory

rm out/target/product/PRODUCT_TYPE/obj/ETC/system_build_prop_intermediates/build.prop

Turn on or turn off the installation of unknown apps

Code modification method

Android 7.1

In the frameworks/base/packages/SettingsProvider/res/values/defaults.xml file, modify the value of def_install_non_market_apps.

false : Close
true : Open

Android10 and above

In Android10, the permanent authorization option of "Allow Unknown Sources" to install applications has been deleted. The switch is no longer found in the system settings. Google will modify the permanent authorization to a separate authorization each time. When the user installs a third party each time The source of the Android software requires manual confirmation of the software permissions.

Turn touch sound on or off

Code modification method

In the frameworks/base/packages/SettingsProvider/res/values/defaults.xml file, modify the value of def_sound_effects_enabled.

false : Close
true : Open

Modify the desktop layout

Code modification method

After the device is turned on, the program shortcuts, small plug-ins, shortcut navigation bar (HotSeat) and folder modification methods that are loaded on the desktop by default.

For details, please refer to the post of the open source community。

Configure USB camera front or rear

The default is front.

Temporary modification method

Front

adb shell setprop persist.sys.uvc.facing front

Back

adb shell setprop persist.sys.uvc.facing back

Code modification method

Android7.1/Android10
- In the device/rockchip/CPU_TYPE/PRODUCT_TYPE/system.prop file, add the following content:
  - Front
```
persist.sys.uvc.facing=front
```
  - Back
```
persist.sys.uvc.facing=back
```
Android11/Android12
- In the device/rockchip/CPU_TYPE/PRODUCT_TYPE/PRODUCT_TYPE.mk file, add the following content:
  - Front
```
PRODUCT_PROPERTY_OVERRIDES += persist.sys.uvc.facing=front
```
  - Back
```
PRODUCT_PROPERTY_OVERRIDES += persist.sys.uvc.facing=back
```

Delete build.prop in the out directory

rm out/target/product/PRODUCT_TYPE/obj/ETC/system_build_prop_intermediates/build.prop

Configure 4K UI

Code modification method：

Platform(RK3399/RK3568)

Android7.1
- In the device/rockchip/CPU_TYPE/PRODUCT_TYPE/system.prop file, add the following content:
```
persist.sys.framebuffer.main=3840x2160@25
```
Android10.0 and above
- In the device/rockchip/CPU_TYPE/PRODUCT_TYPE/PRODUCT_TYPE.mk file, add the following content:
```
PRODUCT_PROPERTY_OVERRIDES += persist.vendor.framebuffer.main=3840x2160@25
```

NOTE: The 4K UI occupies a large amount of system resources and supports a maximum of about 4K25Hz. You are not recommended to use the 4K UI. If you just want to play it 4K video or view 4K pictures, it can not need to configure 4K UI, the system's default video player and picture browser can support.

Platform(RK3588)

Android12.0 and above
- In the device/rockchip/CPU_TYPE/PRODUCT_TYPE/PRODUCT_TYPE.mk file, add the following content:
```
PRODUCT_PROPERTY_OVERRIDES += persist.vendor.framebuffer.main=3840x2160@60
```

NOTE

has strong performance and supports 4K UI at 60Hz.

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