3G模块信息： 中兴的MF626模块，生产厂家ID为 0x19d2，设备ID为 0x0031 。

二、配置内核：

DeviceDrivers---→

USBsupport---→

<*>USB SerialConverter support--→

[*]USBGeneric Serial Driver 

<*>USBdriver for GSM and CDMA modems

DeviceDrivers--→

Network devicesupport---→

<*> PPP (point-to-point protocol) support   
        [*]   PPP multilink support (EXPERIMENTAL)    
        <*>   PPP support for async serial ports      
        <*>   PPP support for sync tty ports          
      <*>   PPP Deflate compression               

 <*>   PPP BSD-Compress compression 

添加设备ID（如果有就不用添加）：

vim drivers/usb/serial/option.c

#define ZTE_VENDOR_ID               0x19d2m drivers/usb/serial/option.c

#define ZTE_PRODUCT_MF626           0x0031

编译内核，下载到开发板重新启动，注意如果用不是ubifs文件系统，记得在启动时把ubifs文件系统挂在上，应为后面使用usb_modeswitch工具时必须挂在ubifs文件系统。

三、制作usb转串口工具

因为我们的3G模块是插在usb串口上的，所以需要制作usb转串口工具

mkdir usb-modeswitch

cd  usb-modeswitch

wget http://pkgs.fedoraproject.org/repo/pkgs/libusb1/libusb-1.0.0.tar.bz2/df2447c23750ef2b4a314200feacc2ee/libusb-1.0.0.tar.bz2

wgethttp://jaist.dl.sourceforge.net/project/libusb/libusb-compat-0.1/libusb-compat-0.1.5/libusb-compat-0.1.5.tar.bz2

wgethttp://pkgs.fedoraproject.org/repo/pkgs/usb_modeswitch/usb-modeswitch-1.2.4.tar.bz2/dbd4ce7966d7b4a5a0604a8280f7164d/usb-modeswitch-1.2.4.tar.bz2

wgethttp://www.draisberghof.de/usb_modeswitch/usb-modeswitch-data-20130607.tar.bz2

以上这些下载地址如果有失效的，搜索相应的文件下载，即可下载再解压即可。

tar xjf libusb-1.0.0.tar.bz2 
tar xjf libusb-compat-0.1.5.tar.bz2 

tar xjf  usb-modeswitch-1.2.4.tar.bz2 

tar xjf usb-modeswitch-data-20130607.tar.bz2

重新编译libusb-1.0.0

[skyyang@centos6 usbmodeswitch]$ cd libusb-1.0.0

[skyyang@centos6libusb-1.0.0]$exportCC=/opt/buildroot-2012.08/arm920t/usr/bin/arm-linux-gcc

[skyyang@centos6libusb-1.0.0]$exportCXX=/opt/buildroot-2012.08/arm920t/usr/bin/arm-linux-g++

[skyyang@centos6 libusb-1.0.0]$export AR=/opt/buildroot-2012.08/arm920t/usr/bin/arm-linux-ar

[skyyang@centos6 libusb-1.0.0]$export AS=/opt/buildroot-2012.08/arm920t/usr/bin/arm-linux-as

[skyyang@centos6 libusb-1.0.0]$export LD=/opt/buildroot-2012.08/arm920t/usr/bin/arm-linux-ld

[skyyang@centos6libusb-1.0.0]$exportSTRIP=/opt/buildroot-2012.08/arm920t/usr/bin/arm-linux-strip

[skyyang@centos6libusb-1.0.0]$exportRANLIB=/opt/buildroot-2012.08/arm920t/usr/bin/arm-linux-ranlib

[skyyang@centos6libusb-1.0.0]$exportnm=/opt/buildroot-2012.08/arm920t/usr/bin/arm-linux-nm

[skyyang@centos6libusb-1.0.0]$./configureCC=/opt/buildroot-2012.08/arm920t/usr/bin/arm-linux-gcc--prefix=/home/skyyang/systools/usbmodeswitch/install --disable-shared--enable-static --build=arm --host=arm-linux

[skyyang@centos6libusb-1.0.0]$make

[skyyang@centos6libusb-1.0.0]$makeinstall

重新编译libusb-compat-0.1.5

[skyyang@centos6 libusb-1.0.0]$cd ../libusb-compat-0.1.5

[skyyang@centos6libusb-compat-0.1.5]$./configureCC=/opt/buildroot-2012.08/arm920t/usr/bin/arm-linux-gcc--prefix=/home/skyyang/systools/usbmodeswitch/install --disable-shared --enable-static--build=arm --host=arm-linux

PKG_CONFIG_PATH=/home/skyyang/systools/usbmodeswitch/libusb-1.0.0

[skyyang@centos6libusb-1.0.0]$make

[skyyang@centos6libusb-1.0.0]$make install

[skyyang@centos6 usbmodeswitch]$ cdusb-modeswitch-1.2.4

[skyyang@centos6usb-modeswitch-1.2.4]$exportCFLAGS="-I/home/skyyang/systools/usbmodeswitch/install/include"

[skyyang@centos6usb-modeswitch-1.2.4]$exportLDFLAGS="-L/home/skyyang/systools/usbmodeswitch/install/lib" 

[skyyang@centos6 usb-modeswitch-1.2.4]$sed -i -e "s|^CC.*|CC          =/opt/buildroot-2012.08/arm920t/usr/bin/arm-linux-gcc|g" Makefile

[skyyang@centos6 usb-modeswitch-1.2.4]$sed -i -e "s|^CFLAGS.*|CFLAGS     += -Wall -I../install/include -static|g" Makefile

[skyyang@centos6 usb-modeswitch-1.2.4]$sed -i -e "s|^LIBS.*|LIBS        =-L../install/lib/ -l usb -l usb-1.0 -l pthread|g" Makefile

[skyyang@centos6 usb-modeswitch-1.2.4]$make

/opt/buildroot-2012.08/arm920t/usr/bin/arm-linux-gcc-o usb_modeswitch usb_modeswitch.c-I/home/skyyang/systools/usbmodeswitch/install/include -Wall-I../install/include -static -L../install/lib/ -l usb -l usb-1.0 -l pthread-L/home/skyyang/systools/usbmodeswitch/install/lib

[skyyang@centos6 usb-modeswitch-1.2.4]$ls

ChangeLog dispatcher.c  Makefile                   make_string.tcl  usb_modeswitch    usb_modeswitch.c     usb_modeswitch.h   usb_modeswitch.tcl

COPYING   jim          make_static_dispatcher.sh README           usb_modeswitch.1  usb_modeswitch.conf  usb_modeswitch.sh

然后将生成的可执行文件 usb_modeswitch 下载到开发板上，插上3G模块：

四、添加必要配置文件：

首先添加zte_mf626.conf配置文件：

vim /apps/etc/ppp/zte_mf626.conf

# ZTE devices
#


DefaultVendor=   0x19d2
DefaultProduct=  0x2000


TargetVendor=   0x19d2
TargetProductList="0001,0002,0015,0016,0017,0031,0037,0052,0055,0063,0064,0066,0091,0108,0117,0128,0157


MessageContent="5553424312345678000000000000061e000000000000000000000000000000"
MessageContent2="5553424312345679000000000000061b000000020000000000000000000000"
MessageContent3="55534243123456702000000080000c85010101180101010101000000000000"


NeedResponse=1

下面三个是拨号上网需要的配置文件：

[root@root /]# vim etc/ppp/peers/wcdma-chat-connect


BORT "BUSY"
ABORT "NO CARRIER"
ABORT "NO DIALTONE"
ABORT "ERROR"
ABORT "NO ANSWER"
TIMEOUT 120
"" AT
OK \rATZ
OK \rAT+CGDCONT=1,"IP","3gnet",,0,0
OK-AT-OK ATDT*99#
CONNECT \d\c

[root@root /]# vim etc/ppp/peers/wcdma


s is pppd script for China liantong
# Usage: root>pppd call cdma


hide-password


noauth
connect '/usr/sbin/chat -s -v -f /etc/ppp/peers/wcdma-chat-connect'
disconnect '/usr/sbin/chat -s -v -f /etc/ppp/peers/wcdma-chat-disconnect'


debug
/dev/ttyUSB2
115200
defaultroute


noipdefault
novj
novjccomp
noccp


ipcp-accept-local
ipcp-accept-remote


local
lock


dump
nodetach


user"card"

[root@root /]# vim etc/ppp/peers/wcdma-chat-disconnect


BORT "ERROR"
ABORT "NO DIALTONE"
SAY "INSending break to the modem\n"
""\k"
""+++ATH"
SAY "\nGood bye\n"

挂在ubifs文件系统

[root@root /]#mount -t usbfs usbfs /proc/bus/usb/

[root@root /]# lsusb
Bus 001 Device 001: ID 1d6b:0001
Bus 001 Device 002: ID 05e3:0606
Bus 001 Device 006: ID 19d2:0031

usb转串口命令：
[root@root /]# ./usb_modeswitch -c /apps/etc/ppp/zte_mf626.conf 


Looking for target devices ...
 No devices in target mode or class found
Looking for default devices ...
   found matching product ID
   adding device
 Found device in default mode, class or configuration (1)
Accessing device 003 on bus 001 ...
Getting the current device configuration ...
 OK, got current device configuration (1)
Using interface number 0
Using endpoints 0x01 (out) and 0x81 (in)
Inquiring device details; driver will be detached ...
Looking for active driver ...
 OK, driver found; name unknown, limitation of libusb1
 OK, driver "unkown" detached


SCSI inquiry data (for identification)
-------------------------
  Vendor String: ZTE     
   Model String: USB SCSI CD-ROM 
Revision String: 2.31
-------------------------


USB description data (for identification)
-------------------------
Manufacturer: ZTE,Incorporated
     Product: ZTE CDMA Technologies MSM
  Serial No.: 1234567890ABCDEF
-------------------------
Setting up communication with interface 0
Using endpoint 0x01 for message sending ...
Trying to send message 1 to endpoint 0x01 ...
 OK, message successfully sent
Reading the response to message 1 (CSW) ...
 OK, response successfully read (13 bytes).
Trying to send message 2 to endpoint 0x01 ...
 OK, message successfully sent
Reading the response to message 2 (CSW) ...
 OK, response successfully read (13 bytes).
Trying to send message 3 to endpoint 0x01 ...
 OK, message successfully sent
Reading the response to message 3 (CSW) ...
 OK, response successfully read (0 bytes).
Resetting response endpoint 0x81
Resetting message endpoint 0x01
 Device is gone, skipping any further commands
-> Run lsusb to note any changes. Bye.

成功后/dev目录会有：

[root@root /]# ls /dev/ttyUSB
ttyUSB0  ttyUSB1  ttyUSB2

[root@root /]# microcom  -s 115200 /dev/ttyUSB1
at
OK

后面的收发短信、打电话和拨号过程和前面GPRS模块完全一样。