1、将目标应用的包名加到如下配置文件中：
    vendor/mediatek/proprietary/frameworks/base/data/etc/pms_sysapp_removable_system_list.txt

    1. com.android.quicksearchbox
    2. com.android.calendar
    3. com.android.dreams.basic
    4. com.android.musicfx
    5. com.android.calculator2
    6. com.android.email
    7. com.android.exchange
    8. com.joyhealth.intelligencefamilydoctor
    9. com.autonavi.amapauto

    2、确保 persist.sys.pms_sys_removable 打开。
    device/mediatek/common/device.mk

    1. ifeq ($(strip $(MTK_CTA_SET)), yes)
    2.   PRODUCT_PROPERTY_OVERRIDES += ro.mtk_cta_set=1
    3.   # Add for PMS support removable system app
    4.   PRODUCT_PROPERTY_OVERRIDES += persist.sys.pms_sys_removable=1
    5. endif

    此配置文件在编译脚本中的位置如下：
    device/mediatek/common/device.mk

    1. # Add for PMS support removable system app
    2. ifneq ($(strip $(MTK_BASIC_PACKAGE)), yes)
    3.   PRODUCT_COPY_FILES += $(call add-to-product-copy-files-if-exists,vendor/mediatek/proprietary/frameworks/base/data/etc/pms_sysapp_removable_system_list.txt:system/etc/permissions/pms_sysapp_removable_system_list.txt)
    4.   PRODUCT_COPY_FILES += $(call add-to-product-copy-files-if-exists,vendor/mediatek/proprietary/frameworks/base/data/etc/pms_sysapp_removable_vendor_list.txt:$(TARGET_COPY_OUT_VENDOR)/etc/permissions/pms_sysapp_removable_vendor_list.txt)
    5. endif

    此配置文件编译输出到目录：system/etc/permissions

    此配置文件在如下文件中引用
    vendor/mediatek/proprietary/frameworks/base/services/core/java/com/mediatek/server/pm/PmsExtImpl.java

    1. // Removable system app
    2. private static HashSet<String> sRemovableSystemAppSet = new HashSet<String>();
    3. // Define a bak removable sys app list, handle whitelist OTA upgade,
    4. // maybe one package is changed from removable to unremovable
    5. private static HashSet<String> sRemovableSystemAppSetBak = new HashSet<String>();
    6. private static boolean sRemovableSysAppEnabled = SystemProperties.getInt(
    7.         "persist.sys.pms_sys_removable", 0) == 1;
    8. private static final File REMOVABLE_SYS_APP_LIST_SYSTEM = Environment
    9.         .buildPath(Environment.getRootDirectory(), "etc", "permissions",
    10.                 "pms_sysapp_removable_system_list.txt");
    11. private static final File REMOVABLE_SYS_APP_LIST_VENDOR = Environment
    12.         .buildPath(Environment.getVendorDirectory(), "etc", "permissions",
    13.                 "pms_sysapp_removable_vendor_list.txt");
    14. // Bak removable sys app file path definition
    15. private static final File REMOVABLE_SYS_APP_LIST_BAK = Environment
    16.         .buildPath(Environment.getDataDirectory(), "system",
    17.                 "pms_sysapp_removable_list_bak.txt");
    18. private static HashSet<String> sUninstallerAppSet = new HashSet<String>();
    21. private void buildRemovableSystemAppSet() {
    22.     if (sRemovableSysAppEnabled) {
    23.         if (sLogEnabled)
    24.             Slog.d(TAG, "BuildRemovableSystemAppSet start");
    25.         sGetRemovableSystemAppFromFile(sRemovableSystemAppSet,
    26.                 REMOVABLE_SYS_APP_LIST_SYSTEM);
    27.         sGetRemovableSystemAppFromFile(sRemovableSystemAppSet,
    28.                 REMOVABLE_SYS_APP_LIST_VENDOR);
    29.         if (sLogEnabled)
    30.             Slog.d(TAG, "BuildRemovableSystemAppSet end");
    31.     }
    32. }
    34. /**
    35.  * Get removable system app list from config file
    36.  *
    37.  * @param resultSet
    38.  *            Returned result list
    39.  * @param file
    40.  *            The config file
    41.  */
    42. private static void sGetRemovableSystemAppFromFile(
    43.         HashSet<String> resultSet, File file) {
    44.     FileReader fr = null;
    45.     BufferedReader br = null;
    46.     try {
    47.         if (file.exists()) {
    48.             fr = new FileReader(file);
    49.         } else {
    50.             Slog.d(TAG, "file in " + file + " does not exist!");
    51.             return;
    52.         }
    53.         br = new BufferedReader(fr);
    54.         String line;
    55.         while ((line = br.readLine()) != null) {
    56.             line = line.trim();
    57.             if (!TextUtils.isEmpty(line)) {
    58.                 if (sLogEnabled)
    59.                     Slog.d(TAG, "read line " + line);
    60.                 resultSet.add(line);
    61.             }
    62.         }
    63.     } catch (IOException io) {
    64.         Slog.d(TAG, io.getMessage());
    65.     } finally {
    66.         try {
    67.             if (br != null) {
    68.                 br.close();
    69.             }
    70.             if (fr != null) {
    71.                 fr.close();
    72.             }
    73.         } catch (IOException io) {
    74.             Slog.d(TAG, io.getMessage());
    75.         }
    76.     }
    77. }