Porting Wifi driver on Android

[android-porting] Porting Wifi driver on Android

Gaan
Tue, 23 Feb 2010 12:05:26 -0800

Hi everyone,

    I'm porting wifi driver (Ralink chip) on Android 2.0.1 board.

first of all I made some modifies



(1)   modify build/target/board/generic/BoardConfig.mk



add HAVE_CUSTOM_WIFI_DRIVER_2 := true







(2)   Android using wpa_supplicant to management wifi. Make sure

external/wpa_supplicant/.config is looking like this



# CONFIG_NO_WPA=y



CONFIG_OS=unix



CONFIG_IEEE8021X_EAPOL=y



CONFIG_EAP_MD5=y



CONFIG_EAP_MSCHAPV2=y



CONFIG_EAP_TLS=y



CONFIG_EAP_PEAP=y



CONFIG_EAP_TTLS=y



CONFIG_EAP_GTC=y



CONFIG_EAP_OTP=y



CONFIG_EAP_SIM=y



CONFIG_EAP_AKA=y



CONFIG_EAP_PSK=y



CONFIG_EAP_SAKE=y



CONFIG_EAP_GPSK=y



CONFIG_EAP_PAX=y



CONFIG_EAP_LEAP=y



# CONFIG_EAP_FAST=y



CONFIG_PKCS12=y



# CONFIG_PCSC=y



CONFIG_SMARTCARD=y



CONFIG_WIRELESS_EXTENSION=y



CONFIG_CTRL_IFACE=y



# CONFIG_DRIVER_HOSTAP=y



# CONFIG_DRIVER_HERMES=y



# CONFIG_DRIVER_MADWIFI=y



# CONFIG_DRIVER_ATMEL=y



CONFIG_DRIVER_WEXT=y



# CONFIG_DRIVER_NDISWRAPPER=y



# CONFIG_DRIVER_BROADCOM=y



# CONFIG_DRIVER_IPW=y



# CONFIG_DRIVER_BSD=y



# CONFIG_DRIVER_NDIS=y



# CONFIG_DRIVER_TEST=y



# CONFIG_DRIVER_CUSTOM=y



# CONFIG_DEBUG_FILE=y



# CONFIG_INTERNAL_LIBTOMMATH=y







(3)   Enable wpa_supplicant compile option, modify external/

wpa_supplicant/Android.mk



(3.1)



LOCAL_PATH := $(call my-dir)







WPA_BUILD_SUPPLICANT := true



ifneq ($(TARGET_SIMULATOR),true)



  ifneq ($(BOARD_WPA_SUPPLICANT_DRIVER),)



    WPA_BUILD_SUPPLICANT := true



    CONFIG_DRIVER_$(BOARD_WPA_SUPPLICANT_DRIVER) = y



  endif







(3.2) remove mark symbol, and look like this



########################





local_target_dir := $(TARGET_OUT)/etc/wifi







include $(CLEAR_VARS)



LOCAL_MODULE := wpa_supplicant.conf



LOCAL_MODULE_TAGS := user



LOCAL_MODULE_CLASS := ETC



LOCAL_MODULE_PATH := $(local_target_dir)



LOCAL_SRC_FILES := $(LOCAL_MODULE)



include $(BUILD_PREBUILT)



#



########################







(4)   Modify wpa_supplicant setting file, and out/target/product/

generic/system/etc/wifi/ will be created after #make in step (3) out/

target/product/generic/system/etc/wifi/wpa_supplicant.conf







(4.1)



# The value can be set to, e.g., udp (ctrl_interface=udp)



#



# For Windows Named Pipe: This value can be used to set the security

descriptor



# for controlling access to the control interface. Security descriptor

can be



# set using Security Descriptor String Format (see http://msdn.microsoft.com/




# library/default.asp?url=/library/en-us/secauthz/security/



# security_descriptor_string_format.asp). The descriptor string needs

to be



# prefixed with SDDL=. For example, ctrl_interface=SDDL=D: would set

an empty



# DACL (which will reject all connections). See README-Windows.txt for

more



# information about SDDL string format.



#



#ctrl_interface=wlan0



ctrl_interface=DIR=/data/system/wpa_supplicant/ GROUP=system







(4.2) setting default AccessPoint value:







# Only WPA-PSK is used. Any valid cipher combination is accepted.



network={



       ssid="example"         // AP name



       proto=WPA            //encypted method



       key_mgmt=WPA-PSK   //using psk



       pairwise=CCMP TKIP



       group=CCMP TKIP WEP104 WEP40



 

psk=06b4be19da289f475aa46a33cb793029d4ab3db7a23ee92382eb0106c72ac7bb



       priority=2



}







(5)   Add directory which is needed when enable wifi under linux,



System/core/rootdir/init.rc











    # give system access to wpa_supplicant.conf for backup and restore



    mkdir /data/misc/wifi 0770 wifi wifi



    chmod 0770 /data/misc/wifi



    chmod 0660 /data/misc/wifi/wpa_supplicant.conf



    mkdir /data/misc/wifi/sockets 0770 wifi wifi



    mkdir /data/misc/android 0770 wifi wifi



    mkdir /data/system/wpa_supplicant 0770 wifi wifi



    mkdir /data/misc/dhcp 0770 dhcp dhcp



    chown dhcp dhcp /data/misc/dhcp



    chmod 0555 /system/bin/busybox







(6)   Modify HAL code, hardware/libhardware_legacy/wifi/wifi.c



Re-define the include path







#ifndef WIFI_DRIVER_MODULE_PATH



//#define WIFI_DRIVER_MODULE_PATH        "/system/lib/modules/wlan.ko"



#define WIFI_DRIVER_MODULE_PATH      "/lib/modules/rt3070sta.ko"



#endif



#ifndef WIFI_DRIVER_MODULE_NAME



//#define WIFI_DRIVER_MODULE_NAME         "wlan"



#define WIFI_DRIVER_MODULE_NAME         "ra0"



#endif



#ifndef WIFI_DRIVER_MODULE_ARG



#define WIFI_DRIVER_MODULE_ARG          ""



#endif



#ifndef WIFI_FIRMWARE_LOADER



#define WIFI_FIRMWARE_LOADER            ""



#endif



#define WIFI_TEST_INTERFACE             "sta"



(7)   Make and place driver relative file after boot.

place rt3070sta.ko at /lib/modules/

place RT2870STA.dat at  /etc/Wireless/RT2870STA/  (it is driver

needed)

place libiw.so.29 at /lib  (it is driver needed)



(8) select "Settings" -> "Wireless&networks" -> "Wi-Fi" in Android

I found the wifi module has been inserted. and I got the logcat.

====================

D/SettingsWifiEnabler( 1153): Received wifi state changed from

Disabled to Enabling

rtusb init --->

ra0 (usb): not using net_device_ops yet

usbcore: registered new interface driver rt2870



====================



but soon it fail and throws the log

====================

init: no such service 'wpa_supplicant'

====================