Android: Android Wifi System

Wifi System:

Java应用层
Java Framework层
JNI层
适配器层
wpa_supplicant程序
Kernel层

Java应用层
-- Settings, WifiSwitcher等应用
--> /system/app
Java Framework层
-- frameworks/base/wifi/java/android/net/wifi/* (android.net.wifi)
-- frameworks/base/services/java/com/android/server/WifiService.java
frameworks/base/services/java/com/android/server/WifiWatchdogService.java
--> /system/framework/framework.jar
/system/framework/services.jar
JNI层
-- frameworks/base/core/jni/android_net_wifi_Wifi.cpp
--> /system/lib/libandroid_runtime.so
适配器层
-- hardware/libhardware_legacy/wifi/wifi.c
--> /system/lib/libhardware_legacy.so
wpa_supplicant程序
-- external/wpa_supplicant
-- external/wpa_supplicant_6
--> /system/bin/wpa_supplicant
/system/lib/libwpa_client.so
Kernel层
-- kernel wifi driver

Enable Wifi 的过程：

Settings/WifiEnabler.java
mWifiManager.setWifiEnabled(enable);
-->
frameworks/base/wifi/java/android/net/wifi/WifiManager.java
public boolean setWifiEnabled(boolean enabled) {
mService.setWifiEnabled(enabled);
}
-->
frameworks/base/services/java/com/android/server/WifiService.java
public boolean setWifiEnabled(boolean enable) {
sendEnableMessage(enable, true, Binder.getCallingUid());
}
->
setWifiEnabledBlocking() {
if (enable) {
mWifiStateTracker.loadDriver();
mWifiStateTracker.startSupplicant();
} else {
mWifiStateTracker.stopSupplicant();
mWifiStateTracker.unloadDriver();
}
}
-->
frameworks/base/wifi/java/android/net/wifi/WifiStateTracker.java
public synchronized boolean loadDriver() {
return WifiNative.loadDriver();
}
public synchronized boolean startSupplicant() {
return WifiNative.startSupplicant();
}
-->
frameworks/base/wifi/java/android/net/wifi/WifiNative.java
public native static boolean loadDriver();
public native static boolean startSupplicant();
-->
frameworks/base/core/jni/android_net_wifi_Wifi.cpp
static jboolean android_net_wifi_loadDriver(JNIEnv* env, jobject clazz)
{
return (jboolean)(::wifi_load_driver() == 0);
}
static jboolean android_net_wifi_startSupplicant(JNIEnv* env, jobject clazz)
{
return (jboolean)(::wifi_start_supplicant() == 0);
}
-->
hardware/libhardware_legacy/wifi/wifi.c
int wifi_load_driver(){
//for build in driver, do nothing
//for .ko driver, insmod/load firmware...
}
int wifi_start_supplicant(){
property_set("ctl.start", "wpa_supplicant");
}
-->
/init.rc
service wpa_supplicant /system/bin/wpa_supplicant ...