Moxa Technologies THINKCORE W311 User manual

ThinkCore W311/321/341 Linux User’s Manual
Second Edition, March 2007
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ThinkCore W311/321/341 Linux User’s Manual
The software described in this manual is furnished under a license agreement and may be used only in
accordance with the terms of that agreement.
Copyright Notice
Copyright ©2007 Moxa Systems Co., Ltd.
All rights reserved.
Reproduction without permission is prohibited.
Trademarks
MOXA is a registered trademark of The Moxa Group.
All other trademarks or registered marks in this manual belong to their respective manufacturers.
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Information in this document is subject to change without notice and does not represent a commitment on the
part of MOXA.
MOXA provides this document “as is,” without warranty of any kind, either expressed or implied, including, but
not limited to, its particular purpose. MOXA reserves the right to make improvements and/or changes to this
manual, or to the products and/or the programs described in this manual, at any time.
Information provided in this manual is intended to be accurate and reliable. However, MOXA assumes no
responsibility for its use, or for any infringements on the rights of third parties that may result from its use.
This product might include unintentional technical or typographical errors. Changes are periodically made to the
information herein to correct such errors, and these changes are incorporated into new editions of the
publication.

Table of Contents
Chapter 1 Introduction..................................................................................................1-1
Overview.................................................................................................................................. 1-2
Software Architecture .............................................................................................................. 1-2
Journaling Flash File System (JFFS2)........................................................................ 1-3
Software Package....................................................................................................... 1-4
Chapter 2 Getting Started.............................................................................................2-1
Powering on the W311/321/341............................................................................................... 2-2
Connecting the W311/321/341 to a PC.................................................................................... 2-2
Serial Console ............................................................................................................ 2-2
Telnet Console............................................................................................................ 2-3
SSH Console .............................................................................................................. 2-4
Configuring the Ethernet Interface .......................................................................................... 2-5
Modifying Network Settings with the Serial Console................................................ 2-5
Modifying Network Settings over the Network ......................................................... 2-6
Configuring the WLAN........................................................................................................... 2-6
IEEE802.11a/b/g ........................................................................................................ 2-6
Using WPA_SUPPLICANT to Support WPA and WPA2.......................................................2-11
SD Slot and USB for Storage Expansion................................................................................2-11
Test Program—Developing Hello.c....................................................................................... 2-13
Installing the Tool Chain (Linux)............................................................................. 2-13
Checking the Flash Memory Space.......................................................................... 2-13
Compiling Hello.c .................................................................................................... 2-14
Uploading and Running the “Hello” Program.......................................................... 2-15
Developing Your First Application ........................................................................................ 2-15
Testing Environment ................................................................................................ 2-16
Compiling tcps2.c..................................................................................................... 2-17
Uploading and Running the “tcps2-release” Program.............................................. 2-18
Testing Procedure Summary .................................................................................... 2-20
Chapter 3 Managing Embedded Linux ........................................................................3-1
System Version Information..................................................................................................... 3-2
System Image Backup.............................................................................................................. 3-2
Upgrading the Firmware............................................................................................. 3-2
Loading Factory Defaults........................................................................................... 3-5
Backing Up the User Directory.................................................................................. 3-5
Deploying the User Directory toAdditional W311/321/341 Units ............................ 3-6
Enabling and Disabling Daemons............................................................................................ 3-6
Setting the Run-Level.............................................................................................................. 3-8
Adjusting the System Time...................................................................................................... 3-9
Setting the Time Manually ......................................................................................... 3-9
NTP Client................................................................................................................ 3-10
Updating the Time Automatically............................................................................. 3-10
Cron—Daemon to Execute Scheduled Commands ................................................................3-11

Chapter 4 Managing Communications........................................................................4-1
Telnet / FTP ............................................................................................................................. 4-2
DNS ......................................................................................................................................... 4-2
Web Service—Apache............................................................................................................. 4-2
Installing PHP for Apache Web Server.................................................................................... 4-4
IPTABLES............................................................................................................................... 4-7
NAT.........................................................................................................................................4-11
NAT Example........................................................................................................... 4-11
Enabling NAT at Bootup.......................................................................................... 4-12
Dial-up Service—PPP............................................................................................................ 4-12
PPPoE.................................................................................................................................... 4-15
NFS (Network File System)................................................................................................... 4-17
Setting up the W311/321/341 as an NFS Client....................................................... 4-18
Mail........................................................................................................................................ 4-18
SNMP .................................................................................................................................... 4-18
OpenVPN............................................................................................................................... 4-27
Chapter 5 Tool Chains for Application Development.................................................5-1
Linux Tool Chain..................................................................................................................... 5-2
Steps for Installing the Linux Tool Chain................................................................... 5-2
Compilation for Applications..................................................................................... 5-2
On-Line Debugging with GDB.................................................................................. 5-3
Windows Tool Chain................................................................................................................ 5-4
System Requirements for Windows Tool Chain......................................................... 5-4
Steps for Installing Windows Tool Chain................................................................... 5-4
Using the BASH Shell................................................................................................ 5-9
Compilation for Applications................................................................................... 5-10
On-Line Debugging with Insight.............................................................................. 5-12
Chapter 6 Programmer’s Guide....................................................................................6-1
Flash Memory Map.................................................................................................................. 6-2
Device API............................................................................................................................... 6-2
RTC (Real Time Clock)...........................................................................................................6-2
Buzzer...................................................................................................................................... 6-3
WDT (Watch Dog Timer) ........................................................................................................ 6-3
UART....................................................................................................................................... 6-7
DO ........................................................................................................................................... 6-8
Chapter 7 Software Lock...............................................................................................7-1
Chapter 8 UC Finder......................................................................................................8-1
Windows UC Finder................................................................................................................ 8-2
Installing the Software................................................................................................ 8-2
Broadcast Search........................................................................................................ 8-3
Linux ucfinder.......................................................................................................................... 8-4

Appendix A System Commands.....................................................................................A-1
busybox (V0.60.4): Linux normal command utility collection............................................... A-1
File manager.............................................................................................................. A-1
Editor......................................................................................................................... A-1
Network..................................................................................................................... A-1
Process....................................................................................................................... A-2
Other.......................................................................................................................... A-2
MOXA special utilities.............................................................................................. A-2
Appendix B Service Information.....................................................................................B-1
MOXA Internet Services..........................................................................................................B-2
Problem Report Form ..............................................................................................................B-3
Product Return Procedure........................................................................................................B-4

1
1
Chapter 1 Introduction
The MOXAThinkCore W311/321/341 are RISC-based ready-to-run wireless embedded computers
with 802.11a/b/g WLAN, one 10/100 Mbps Ethernet port, an internal SD socket, 1/2/4
RS-232/422/485 serial ports, two USB 2.0 hosts, one relay output channel, and pre-installed Linux
operating system. The W311/321/341 offer high performance communication and unlimited
storage in a super compact, palm-size ARM9 box. The ThinkCore W300 Series is the right
solution for embedded applications that are used in hard-to-wire environments and that require a
large amount of memory, but that must be housed in a small space without sacrificing
performance.
The following topics are covered in this chapter:
Overview
Software Architecture
¾Journaling Flash File System (JFFS2)
¾Software Package

ThinkCore W311/321/341 Linux User’s Manual Introduction
1-2
Overview
The ThinkCore W311/321/341 wireless embedded computers support 802.11a/b/g wireless LANs
with data encryption functions, including the common WEP and powerful WPA and WPA2, to
establish a secure transmission tunnel over a WLAN.
ThinkCore W300 Series Embedded Computers use a MOXA ART 192 Mhz RISC CPU. Unlike
the X86 CPU, which uses a CISC design, the RISC architecture and modern semiconductor
technology provide these embedded computers with a powerful computing engine and
communication functions, but without generating a lot of heat. A 16 MB NOR Flash ROM and
on-board SDRAM (64 MB for W341 and 32 MB for W311/321) give you enough memory to
install your application software directly on the embedded computer. In addition, dual LAN ports
are built right into the RISC CPU. This network capability, in combination with the ability to
control serial devices, makes the ThinkCore W300 Series ideal as communication platforms for
data acquisition and industrial control applications.
The pre-installed Linux operating system (OS) provides an open software operating system for
your software program development. Software written for desktop PCs can be easily ported to the
computer with a GNU cross compiler, without needing to modify the source code. The OS, device
drivers (e.g., serial and buzzer control), and your own applications, can all be stored in the NOR
Flash memory.
Software Architecture
The Linux operating system that is pre-installed in the W311/321/341 follows the standard Linux
architecture, making it easy to accept programs that follow the POSIX standard. Program porting
is done with the GNU Tool Chain provided by MOXA. In addition to Standard POSIX APIs,
device drivers for the USB storage, buzzer and Network controls, and UART are also included in
the Linux OS.
AP
API
Protocol
Stack
Device
Driver
Microkernel
User Application Daemon (Apache, Telnet, FTPD, SNMP)
Application Interface (POSIX, Socket, Secure Socket)
TCP, IP, UDP, CMP, ARP, HTTP, SNMP, SMTP
PCMCIA, CF, WLAN, USB, UART, RTC, LCM, Keypad
Memory control, Schedule, Process
RS-232/422/485, Ethernet, PCMCIA, CompactFlash, USB
File
System
Hardware
OS Kernel
The W311/321/341’s built-in Flash ROM is partitioned into Boot Loader, Linux Kernel, Root
File System, and User directory partitions.
In order to prevent user applications from crashing the Root File System, the W311/321/341 use a
specially designed Root File System with Protected Configuration for emergency use. This
Root File System comes with serial and Ethernet communication capability for users to load the

ThinkCore W311/321/341 Linux User’s Manual Introduction
1-3
Factory Default Image file. The user directory saves the user’s settings and application.
To improve system reliability, the W311/321/341 have a built-in mechanism that prevents the
system from crashing. When the Linux kernel boots up, the kernel will mount the root file system
for read only, and then enable services and daemons. At the same time, the kernel will start
searching for system configuration parameters via rc or inittab.
Normally, the kernel uses the Root File System to boot up the system. The Root File System is
protected, and cannot be changed by the user. This type of setup creates a “safe” zone.
For more information about the memory map and programming, refer to Chapter 6, Programmer’s
Guide.
Journaling Flash File System (JFFS2)
The Root File System and User directory in the flash memory is formatted with the Journaling
Flash File System (JFFS2). The formatting process places a compressed file system in the flash
memory. This operation is transparent to the user.
The Journaling Flash File System (JFFS2), which was developed by Axis Communications in
Sweden, puts a file system directly on the flash, instead of emulating a block device. It is designed
for use on flash-ROM chips and recognizes the special write requirements of a flash-ROM chip.
JFFS2 implements wear-leveling to extend the life of the flash disk, and stores the flash directory
structure in the RAM. A log-structured file system is maintained at all times. The system is always
consistent, even if it encounters crashes or improper power-downs, and does not require fsck (file
system check) on boot-up.
JFFS2 is the newest version of JFFS. It provides improved wear-leveling and garbage-collection
performance, improved RAM footprint and response to system-memory pressure, improved
concurrency and support for suspending flash erases, marking of bad sectors with continued use of
the remaining good sectors (enhancing the write-life of the devices), native data compression
inside the file system design, and support for hard links.
The key features of JFFS2 are:
yTargets the Flash ROM Directly
yRobustness
yConsistency across power failures
yNo integrity scan (fsck) is required at boot time after normal or abnormal shutdown
yExplicit wear leveling
yTransparent compression
Although JFFS2 is a journaling file system, this does not preclude the loss of data. The file system
will remain in a consistent state across power failures and will always be mountable. However, if
the board is powered down during a write then the incomplete write will be rolled back on the next
boot, but writes that have already been completed will not be affected.
Additional information about JFFS2 is available at:
http://sources.redhat.com/jffs2/jffs2.pdf
http://developer.axis.com/software/jffs/
http://www.linux-mtd.infradead.org/

ThinkCore W311/321/341 Linux User’s Manual Introduction
1-4
Software Package
Boot Loader Moxa Boot Loader (v1.2)
Kernel Linux 2.6.9
Protocol Stack ARP, PPP, CHAP, PAP, IPv4, ICMP, TCP, UDP, DHCP, FTP, SNMP
V1/V3, HTTP, NTP, NFS, SMTP, SSH 1.0/2.0, SSL, Telnet, PPPoE,
OpenVPN
File System JFFS2, NFS, Ext2, Ext3, VFAT/FAT
OS shell command Bash
Busybox Linux normal command utility collection
Utilities
tinylogin login and user manager utility
telnet telnet client program
ftp FTP client program
smtpclient email utility
scp Secure file transfer Client Program
Daemons
pppd dial in/out over serial port daemon
snmpd snmpd agent daemon
telnetd telnet server daemon
inetd TCP server manager program
ftpd ftp server daemon
apache web server daemon
sshd secure shell server
openvpn virtual private network
openssl open SSL
Linux Tool Chain
Gcc (V3.3.2) C/C++ PC Cross Compiler
GDB (V5.3) Source Level Debug Server
Glibc (V2.2.5) POSIX standard C library
Windows Tool Chain
Gcc (V3.3.2) C/C++ PC Cross Compiler
Glibc(V2.2.5) POSIX standard C library
Insight (V6.1) Windows environment source level debug utility

2
2
Chapter 2 Getting Started
In this chapter, we explain how to connect the W311/321/341, how to turn on the power, how to
get started programming, and how to use the W311/321/341’s other functions.
The following topics are covered in this chapter:
Powering on the W311/321/341
Connecting the W311/321/341 to a PC
¾Serial Console
¾Telnet Console
¾SSH Console
Configuring the Ethernet Interface
¾Modifying Network Settings with the Serial Console
¾Modifying Network Settings over the Network
Configuring the WLAN
¾IEEE802.11a/b/g
Using WPA_SUPPLICANT to Support WPA and WPA2
SD Socket and USB for Storage Expansion
Test Program—Developing Hello.c
¾Installing the Tool Chain (Linux)
¾Checking the Flash Memory Space
¾Compiling Hello.c
¾Uploading and Running the “Hello” Program
Developing Your First Application
¾Testing Environment
¾Compiling tcps2.c
¾Uploading and Running the “tcps2-release” Program
¾Testing Procedure Summary