AM335X开发板+4G模块 调试小结

1、找到开发版配套资料中的linux内核源码包linux-3.2.0-Litev2.3-nand-2017-3-24.tar.gz

2、解压内核源码包，打开内核源码文件 option.c(路径为 drivers/usb/serial/option.c) 

3、在源码中找到 option_ids 数组，在数组中添加 Longsung 产品的 VID(0x1C9E)和 PID(0x9B3C) 

4、重新编译内核 ./build.sh （必须在ubuntu14.04版本下编译），更新开发板的内核。

5、修改开发版上gprs-connect-chat文件（路径为/etc/ppp/gprs-connect-chat）内容如下

TIMEOUT         15
ABORT           "DELAYED"
ABORT           "BUSY"
ABORT           "ERROR"
ABORT           "NO DIALTONE"
ABORT           "NO CARRIER"
TIMEOUT         40
''              \rAT
OK                ATS0=0
OK              ATE0V1
OK              AT+CGDCONT=1,"IP","ctnet"
OK              ATDT*99***1#
CONNECT         ''

注:插入不同运营商的卡，AT+CGDCONT=1,"IP","ctnet"最后一个参数不同，此为中国电信APN。 

6、修改拨号配置文件（/etc/ppp/peer/gprs）内容如下

# Usage: root>pppd call gprs
/dev/ttyUSB1
9600
crtscts
modem
#noauth
debug
nodetach
#hide-password
usepeerdns
noipdefault
defaultroute
0.0.0.0:0.0.0.0
ipcp-accept-local
ipcp-accept-remote
#lcp-echo-failure 12
#lcp-echo-interval 3
#noccp
#novj
#novjccomp
#persist
connect '/usr/sbin/chat -s -v -f /etc/ppp/gprs-connect-chat'

7、拨号使用以下指令（# pppd call gprs），断开网络使用以下指令（# killall pppd）

8、修改开发板Linux系统网络配置文件（interfaces），内容如下

# /etc/network/interfaces -- configuration file for ifup(8), ifdown(8)
 
# The loopback interface
auto lo
iface lo inet loopback

# Wireless interfaces
iface wlan0 inet dhcp
    wireless_mode managed
    wireless_essid any
    wpa-driver wext
    wpa-conf /etc/wpa_supplicant.conf

iface tiwlan0 inet dhcp
    wireless_mode managed
    wireless_essid any

iface atml0 inet dhcp

# Wired or wireless interfaces
auto eth0                                
#iface eth0 inet dhcp                    
#        pre-up /bin/grep -v -e "ip=[0-9]\+\.[0-9]\+\.[0-9]\+\.[0-9]\+" /proc/cm
iface eth0 inet static                                                          
address 192.168.1.4                                                            
gateway 192.168.1.1                                                             
netmask 255.255.255.0                                                           
dns-nameservers 114.114.114.114 223.5.5.5
                                                                               
#auto eth1                                                                       
#iface eth1 inet dhcp                                                           
iface eth1 inet static                                                          
address 10.10.80.15                                                             
gateway 10.10.80.1                                                              
netmask 255.0.0.0   

# Ethernet/RNDIS gadget (g_ether)
# ... or on host side, usbnet and random hwaddr
iface usb0 inet dhcp

# Bluetooth networking
iface bnep0 inet dhcp

9、修改开发板Linux系统开机启动脚本（S99sztenv），内容如下

#!/bin/sh
#
sleep 10s
echo start 4g call
pppd call gprs &
sleep 5s
echo configure route
route del default gw 192.168.1.1
route add default gw 10.64.64.64