===== VIM1S System Permissions for APP =====
If a third-party application wants to obtain system permissions, it needs to declare its UID as a system process in the ''AndroidManifest.xml'' file, and the application needs to be signed with the platform key (signature).

===== Declare UID as a System Process =====

The third-party application's AndroidManifest.xml must include:
```sh
android:sharedUserid="android.uid.system"
```

===== Sign APP with Platform Key =====

==== APP Signing for SDK Source Code ====

1. Put the APK in the application directory, and create an ''Android.mk'' file containing the following contents:
```sh
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
# module name should match the apk name
LOCAL_MODULE := XXXX
LOCAL_MODULE_TAGS := optional

LOCAL_SRC_FILES := $(LOCAL_MODULE).apk
LOCAL_MODULE_CLASS := APPS
LOCAL_MODULE_SUFFIX := $(COMMON_ANDROID_PACKAGE_SUFFIX)
LOCAL_PRIVILEGED_MODULE := true

# use the application's own signature
# LOCAL_CERTIFICATE := PRESIGNED
# sign with the platform key
LOCAL_CERTIFICATE := platform
include $(BUILD_PREBUILT)
```

2. Add the name of your APK ''XXXX'' into the compile file.
```sh
PRODUCT_PACKAGES +=\
   Bluetooth \
   XXXX
```

3. Recompile the SDK, and the APK file will be generated in the ''out'' directory, containing the platform key.

==== APP Signing for Windows & Linux PC ====

1. According to your SBC model and system version, download the two platform key files [[https://dl.khadas.com/products/vim1s/development/signtools/platform.x509.pem|platform.x509.pem]] and [[https://dl.khadas.com/products/vim1s/development/signtools/platform.pk8|platform.pk8]].

2. Download the Java Signing Tool [[https://dl.khadas.com/products/vim1s/development/signtools/signapk.jar|signapk.jar]].

3. Download the library-dependency [[https://dl.khadas.com/products/vim1s/development/signtools/libconscrypt_openjdk_jni.so|libconscrypt_openjdk_jni.so]] and put it in the ''signlib'' directory.

4. Install the [[https://docs.oracle.com/en/java/javase/17/install/overview-jdk-installation.html|JDK Tool]].

5. Execute the shell command:
```sh
java -Djava.library.path=signlib -jar signapk.jar platform.x509.pem platform.pk8 unsigned.apk signed.apk
```