问题
有的MVNO卡没有配置过 CarrierConfig及相关 overlay，但是实际运行的时候功能被override了 ，此时可能是因为CarrierConfig用了父类（同MCCMNC等情况）的配置，因此在直接查找对应卡cid或mccmnc+mvno属性时候的CarrierConfig是没办法找到影响功能的配置项的。
代码逻辑
fw/opt/telephony
frameworks/opt/telephony/src/java/com/android/internal/telephony/ServiceStateTracker.java
AOSP源码getServiceProviderName接口，从CarrierConfig中读取配置是否覆写运营商名称，两个KEY共同控制
- KEY_CARRIER_NAME_OVERRIDE_BOOL
- KEY_CARRIER_NAME_STRING
//Android S version example
//frameworks/opt/telephony/src/java/com/android/internal/telephony/ServiceStateTracker.java/*** Get the service provider name with highest priority among various source.* @return service provider name.*/public String getServiceProviderName() {// BrandOverride has higher priority than the carrier configString operatorBrandOverride = getOperatorBrandOverride();if (!TextUtils.isEmpty(operatorBrandOverride)) {return operatorBrandOverride;}String carrierName = mIccRecords != null ? mIccRecords.getServiceProviderName() : "";PersistableBundle config = getCarrierConfig();if (config.getBoolean(CarrierConfigManager.KEY_CARRIER_NAME_OVERRIDE_BOOL)|| TextUtils.isEmpty(carrierName)) {return config.getString(CarrierConfigManager.KEY_CARRIER_NAME_STRING);}return carrierName;}
CarrierConfig APP
packages/apps/CarrierConfig/src/com/android/carrierconfig/
DefaultCarrierConfigService.java 中通过loadConfig接口加载出对应卡的配置
- loadConfig -> readConfigFromXml
加载先后，越后加载的会覆盖前面的
- id.getSpecificCarrierId()
- id.getCarrierId()
- mccmncCarrierId
※然后会有优先级加载配置，所以会
public class DefaultCarrierConfigService extends CarrierService {private static final String CARRIER_ID_PREFIX = "carrier_config_carrierid_";private static final String MCCMNC_PREFIX = "carrier_config_mccmnc_";private static final String NO_SIM_CONFIG_FILE_NAME = "carrier_config_no_sim.xml";//无卡配置的文件名private XmlPullParserFactory mFactory;public DefaultCarrierConfigService() {Log.d(TAG, "Service created");mFactory = null;}PersistableBundle loadConfig(XmlPullParser parser, @Nullable CarrierIdentifier id) {PersistableBundle config = new PersistableBundle();// OEM customizable filter for carrier requirements not related to hardware/vendor SKU.String sku = getApplicationContext().getResources().getString(R.string.sku_filter);if (id == null) {try {// Load no SIM config if carrier id is not set.parser.setInput(getApplicationContext().getAssets().open(NO_SIM_CONFIG_FILE_NAME), "utf-8");config = readConfigFromXml(parser, null, sku);// Treat vendor_no_sim.xml as if it were appended to the no sim config file.XmlPullParser vendorInput =getApplicationContext().getResources().getXml(R.xml.vendor_no_sim);PersistableBundle vendorConfig = readConfigFromXml(vendorInput, null, sku);config.putAll(vendorConfig);}catch (IOException|XmlPullParserException e) {Log.e(TAG, "Failed to load config for no SIM", e);}return config;}try {if (id.getCarrierId() != TelephonyManager.UNKNOWN_CARRIER_ID) {PersistableBundle configByCarrierId = new PersistableBundle();PersistableBundle configBySpecificCarrierId = new PersistableBundle();PersistableBundle configByMccMncFallBackCarrierId = new PersistableBundle();TelephonyManager telephonyManager = getApplicationContext().getSystemService(TelephonyManager.class)
