Add USB WIFI to your system

我也要试着在Q7上试验一下

转自http://hi.baidu.com/aokikyon/blog/item/1e16931e675de11440341753.html

 

编译Android操作系统（2）——添加Wifi支持

Rockie Cheng

Now,zd1211b无线网卡已可使用wpa_supplicant连接无线网络，下一步要让android能够识别无线网卡。

Android默认使用wifi.c加载无线网卡驱动模块，如果直接编译进内核需要做一定修改。

btw:需要内核支持wifi和dhcp

（1）build/target/board/idea6410/BoardConfig.mk
add

# Wifi related defines
BOARD_WPA_SUPPLICANT_DRIVER := WEXT

（2）external/wpa_supplicant/.config
# 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_PKCS12=y
CONFIG_SMARTCARD=y
CONFIG_WIRELESS_EXTENSION=y
CONFIG_CTRL_IFACE=y
CONFIG_DRIVER_WEXT=y

 

it seems there is a problem with driver_wext.c in eclar，so I got one from cupcake.

（3）hardware/libhardware_legacy/wifi/wifi.c
将驱动直接编译进内核

int wifi_load_driver()
{
    char driver_status[PROPERTY_VALUE_MAX];
    int count = 100; /* wait at most 20 seconds for completion */

LOGE("wifi driver loaded ！");

        return 0;
}

 

int wifi_unload_driver()
{
    int count = 20; /* wait at most 10 seconds for completion */
LOGE("wifi driver unloaded by rockie!");
return 0;

注意这个定义static const char IFACE_DIR[]           = "/data/system/wpa_supplicant";

（4）编译整个android系统，确认编译完bin目录中含有wpa_supplicant、wpa_cli

（5）修改init.rc文件
add

mkdir /data/misc/wifi 0770 system system
mkdir /data/misc/wifi/sockets 0770 system system
mkdir /data/system/wpa_supplicant 0770 system system
chmod 0660 /data/misc/wifi/wpa_supplicant.conf

add at the end

service wpa_supplicant /system/bin/wpa_supplicant -Dwext -iwlan0 -d -c /data/misc/wifi/wpa_supplicant.conf
#    user wifi
#    group wifi system
    socket wpa_eth0 dgram 0660 wifi system
    disabled
    oneshot

service dhcpcd /system/bin/dhcpcd -f /system/etc/dhcpcd/dhcpcd.conf -d wlan0
    disabled
    oneshot
   
on property:init.svc.wpa_supplicant=stopped
    stop dhcpcd

（6）添加system/etc/wifi/wpa_supplicant.conf
update_config=1
ctrl_interface=/data/system/wpa_supplicant //这个一定要和IFACE_DIR对应并保证目录权限
eapol_version=1
ap_scan=1
fast_reauth=1

（7）/system/etc/dhcpcd/dhcpcd.conf 文件内容

interface wlan0

option subnet_mask, routers, domain_name_servers

（8）boot and try

存在的问题是无法获取wifi的信号强度