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Realtek Wi-Fi SDK for Android
Version 2.1
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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_20120618.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.
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1. Platform Related Files [MUST]
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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
¡° 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.
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2. libwpa_client [MUST]
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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 $(BUILD_SHARED_LIBRARY)
endif
Reference files:
external/hostapd-0.6.9_rtl/*
external/wpa_supplicant/Android.mk
external/wpa_supplicant_6/Android.mk
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3. libhardware_legacy [MUST]
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The libhardware_legacy library includes functionality for Wi-Fi to operate.
We have made modifications and extensions for our Wi-Fi solution. To apply this:
a. Copy necessary files
Copy our wifi_realtek.c into hardware/libhardware_legacy/wifi folder of your
platform.
b. Include wifi_realtek.c into source files
Modify hardware/libhardware_legacy/wifi/Android.mk to include wifi_realtek.c
instead of wifi.c into LOCAL_SRC_FILES. For example:
ifeq ($(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
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4. dhcpcd [SUGGEST]
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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
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5. wpa_supplicant
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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
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6. netd [MUST for Portable Wi-Fi hotspot]
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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
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7. Opening Portable Wi-Fi Hotspot UI
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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
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8. Patch for WifiSettings.java
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The WifiSettings UI page has bug which doesn't get lastest WiFi information.
We provide patch to fix this problem. Add the following 4 line at the beginning
of function updateAccessPoints():
mLastInfo = mWifiManager.getConnectionInfo();
mLastState = WifiInfo.getDetailedStateOf(mLastInfo.getSupplicantState());
if(mLastState == DetailedState.OBTAINING_IPADDR && mLastInfo.getIpAddress() != 0)
mLastState = DetailedState.CONNECTED;
Reference files:
packages\apps\Settings\src\com\android\settings\wifi\WifiSettings.java
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9. Driver Configuration and Compilation
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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"
Download Driver Pack
After your driver has been downloaded, follow these simple steps to install it.
Expand the archive file (if the download file is in zip or rar format).
If the expanded file has an .exe extension, double click it and follow the installation instructions.
Otherwise, open Device Manager by right-clicking the Start menu and selecting Device Manager.
Find the device and model you want to update in the device list.
Double-click on it to open the Properties dialog box.
From the Properties dialog box, select the Driver tab.
Click the Update Driver button, then follow the instructions.
Very important: You must reboot your system to ensure that any driver updates have taken effect.
For more help, visit our Driver Support section for step-by-step videos on how to install drivers for every file type.