================================================================================
Realtek Wi-Fi SDK for Android
Version 2.0
================================================================================
	This document provides a simple guide to help engineers to apply Realtek
Wi-Fi solution onto their Android system. For now, we have supported the
following Wi-Fi functionality on Android up to 2.3:
	1. Standard STA mode
	2. Portable Wi-Fi Hotspot(SoftAP mode)
	
	To port Realtek Wi-Fi driver onto Android platform, you can go through the
following guide with reference codes within our driver package's
realtek_wifi_SDK_for_android_20111103.tar.gz.


	Because Android's SDK may differ from platform to platform, our reference
codes may not be applied on every platform without modifications. You should
check if our reference code is suitable for you to use.

================================================================================
1. Platform Related Files [MUST]
================================================================================
a. BOARD_USES_REALTEK_WIFI := true
	Ensure "BOARD_USES_REALTEK_WIFI := true" is defined in BoardConfig.mk. This
	is for some compile-time choices to be applied for our Wi-Fi solution.

b. BOARD_WPA_SUPPLICANT_DRIVER := WEXT
	Our driver implements the wireless extension interface for communication
	with user space programs. For wpa_supplicant, it's needed to set
	"BOARD_WPA_SUPPLICANT_DRIVER := WEXT" in BoardConfig.mk to make
	wpa_supplicant use the interface implemented in driver_wext.c to communicate
	with our driver.

c. WPA_SUPPLICANT_VERSION := VER_0_6_X
	Android provides both wpa_supplicant and wpa_supplicant_6 inside. We suggest
	using wpa_supplicant_6. You can set "WPA_SUPPLICANT_VERSION := VER_0_6_X" in
	the BoardConfig.mk to use wpa_supplicant_6 for your platform.
	
d. Service definitions
	Make sure the service definitions of wpa_supplicant, dhcpd, hostapd is
	defined in init.rc or init.xxx.rc for your platform. As following:

service wpa_supplicant /system/bin/wpa_supplicant -Dwext -iwlan0 -c/data/misc/wifi/wpa_supplicant.conf
	disabled
	oneshot

service hostapd /system/bin/hostapd_wps /data/misc/wifi/hostapd.conf
	disabled
	oneshot

service dhcpcd /system/bin/dhcpcd -ABKL
	disabled
	oneshot

	กฐ The hostapd service is for Porttable Wi-Fi Hotspot. If you don't want to
	use Porttable Wi-Fi Hotspot for your platfrom, you can ignore it.

================================================================================
2. libwpa_client [MUST]
================================================================================
	The libwpa_client library is linked into libhardware_legacy library for
Wi-Fi to communicate with wpa_supplicant. Instead of using the original
libwpa_client of wpa_supplicant or wpa_supplicant_6, we use the libwpa_client of
hostapd-0.6.9_rtl from us to provide extension functionalities for our Wi-Fi
solutions. To apply this:

a. Copy necessary files
	Copy our hostapd-0.6.9_rtl/ folder into external/ folder of your platform.

b. Prevent the original libwpa_client to be compiled
	Modify the external/wpa_supplicant/Android.mk and
	external/wpa_supplicant_6/Android.mk to prevent the libwpa_client to be
	compiled from wpa_supplicant and wpa_supplicant_6. For example:

ifneq ($(BOARD_USES_REALTEK_WIFI),true)
include $(CLEAR_VARS)
LOCAL_MODULE = libwpa_client
LOCAL_CFLAGS = $(L_CFLAGS)
LOCAL_SRC_FILES = wpa_ctrl.c os_unix.c
LOCAL_C_INCLUDES = $(INCLUDES)
LOCAL_SHARED_LIBRARIES := libcutils
LOCAL_COPY_HEADERS_TO := libwpa_client
LOCAL_COPY_HEADERS := wpa_ctrl.h
include $(BUILD_SHARED_LIBRARY)
endif 
	
Reference files:
	external/hostapd-0.6.9_rtl/*
	external/wpa_supplicant/Android.mk
	external/wpa_supplicant_6/Android.mk

================================================================================
3. libhardware_legacy [MUST]
================================================================================
	The libhardware_legacy library includes functionality for Wi-Fi to operate.
We have made modifications and extensions for our Wi-Fi solution. To apply this:

a. Copy necessary files
	Copy our wifi_realtek.c into hardware/libhardware_legacy/wifi folder of your
	platform.

b. Include wifi_realtek.c into source files
	Modify hardware/libhardware_legacy/wifi/Android.mk to include wifi_realtek.c
	instead of wifi.c into LOCAL_SRC_FILES. For example:
	
ifeq ($(BOARD_USES_REALTEK_WIFI),true)
	LOCAL_SRC_FILES += wifi/wifi_realtek.c
else
	LOCAL_SRC_FILES += wifi/wifi.c
endif
	
Reference files:
	hardware/libhardware_legacy/wifi/Android.mk
	hardware/libhardware_legacy/wifi/wifi_realtek.c
	
================================================================================
4. dhcpcd [SUGGEST]
================================================================================
	We have made some modifications for dhcpcd. To apply this:
	
a. Copy necessary files
	Copy our client_realtek.c and logger_realtek.c into external/dhcpcd folder of
	your platform.
	
b. Include logger_realtek.c and client_realtek.c into source files
	Modify external/dhcpcd/Android.mk to include logger_realtek.c and
	client_realtek.c instead of logger.c and client.c into LOCAL_SRC_FILES. For
	example:

ifeq ($(BOARD_USES_REALTEK_WIFI),true)
LOCAL_SRC_FILES += logger_realtek.c client_realtek.c
else
LOCAL_SRC_FILES += logger.c client.c
endif

c. Include libhardware_legacy into shared libraries
	Modify external/dhcpcd/Android.mk to include libhardware_legacy into
	LOCAL_SHARED_LIBRARIES. For example:
	
ifeq ($(BOARD_USES_REALTEK_WIFI),true)
LOCAL_SHARED_LIBRARIES += libhardware_legacy
endif
	
Reference files:
	external/dhcpcd/Android.mk
	external/dhcpcd/client_realtek.c
	external/dhcpcd/logger_realtek.c
	
================================================================================
5. wpa_supplicant
================================================================================
a. Version of wpa_supplicant
	We suggest using wpa_supplicant_6 of Android. See 1.c. for reference.

b. Prevent the original libwpa_client to be compiled
	Because we use libwpa_client from hostapd-0.6.9_rtl. We should prevent the
	original libwpa_client of wpa_supplicant and wpa_supplicant_6 to be compiled.
	See '2. libwpa_client' for reference.
	
c. wpa_supplicant.conf
	Following is the reference content of wpa_supplicant.conf:
	
ctrl_interface=DIR=/data/misc/wifi/wpa_supplicant GROUP=wifi
update_config=1
ap_scan=1

Reference files:
	external/wpa_supplicant/Android.mk

================================================================================
6. netd [MUST for Portable Wi-Fi hotspot]
================================================================================
	The Portable Wi-Fi hotspot functionality is controlled by the
SoftapController subfunction of netd. We provide our own SoftapController
implementation to run our hostapd daemon for softap mode. To apply this:

a. Copy necessary files
	Copy our SoftapController_realtek.cpp into system/netd/ folder of your
	platform.
	
b. Include SoftapController_realtek.cpp into source files
	Modify system/netd/Android.mk to include SoftapController_realtek.cpp
	instead of SoftapController.cpp into LOCAL_SRC_FILES. For example:

ifeq ($(BOARD_USES_REALTEK_WIFI), true)
    LOCAL_SRC_FILES += SoftapController_realtek.cpp
else
    LOCAL_SRC_FILES += SoftapController.cpp 
endif

c. Include libhardware_legacy into shared libraries
	Modify system/netd/Android.mk to include libhardware_legacy into
	LOCAL_SHARED_LIBRARIES. For example:

ifeq ($(BOARD_USES_REALTEK_WIFI), true)
    LOCAL_SHARED_LIBRARIES += libhardware_legacy
endif

Reference files:
	system/netd/Android.mk
	system/netd/SoftapController_realtek.cpp

================================================================================
7. Opening Portable Wi-Fi Hotspot UI
================================================================================
	We should set interface item to the following two resource configurations of
your platform to show the UI for Portable Wi-Fi Hotspot.

a. config_tether_wifi_regexs
	The interfaces set here is used as the interfaces for Wi-Fi LAN port. We use
	'wlap0' by default when our wifi is set as softap mode. So it needs to set
	'wlap0' here for system to recognized 'wlap0' as Wi-Fi LAN port.
	For example:
	
<string-array translatable="false" name="config_tether_wifi_regexs">
		<item>"wlap0"</item>
</string-array>
	
b. config_tether_upstream_regexs
	The interfaces set here are used as the interfaces for WAN port to connect
	to internet. Usually, 'ppp0' used by 3G, 'eth0' used by ethernet, 'wlan0'
	used by Wi-Fi can be set here. For example:

<string-array translatable="false" name="config_tether_upstream_regexs">
		<item>"ppp\\d"</item>
		<item>"eth\\d"</item>
		<item>"wlan\\d"</item>
</string-array>
	
	Android will apply DHCP server function for Wi-Fi LAN port, and setup NAT
between Wi-Fi LAN port and WAN port automatically.
	
Reference files:
	frameworks/base/core/res/res/values/config.xml

================================================================================
8. Driver Configuration and Compilation 
================================================================================
a. MODULE_NAME defined in Makefile
	For android to rmmod the wifi driver module, the driver module name, which
	is decided in compilation time as MODULE_NAME defined in Makefile, should be
	the same as WIFI_DRIVER_MODULE_NAME defined in wifi_realtek.c:
		
#define WIFI_DRIVER_MODULE_NAME	 "wlan"

b. Driver Compilation
	For driver compilation, please refer to:
		doument/Quick_Start_Guide_for_Driver_Compilation_and_Installation.pdf
	
c. Where to place wifi driver module
	If you compile wifi driver as .ko file, you should place wifi driver module
	to the path defined in wifi_realtek.c with WIFI_DRIVER_MODULE_PATH macro.
	The default path defined in wifi_realtek.c:

#define WIFI_DRIVER_MODULE_PATH	"/system/wifi/wlan.ko"
