Moxa Technologies UC-7420/7410 - Manual (Page 17)

UC-7420/7410 User’s Manual Introduction
1-12
Software Introduction
Software Architecture
The Linux operating system that is pre-installed in UC-7420/7410 follows the standard Linux
architecture, making it easy to port programs that follow the POSIX standard to UC-7420/7410.
Porting is done with the GNU Tool Chain provided by Moxa. In addition to the Standard POSIX
API, device drivers for the LCM, buzzer and Keypad controls, USB/CompactFlash mass storage,
UART, and Wireless LAN PCMCIA card are also included in the UC-7420/7410 Linux system.
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
UC-7420/7410’s Flash ROM is partitioned into Boot Loader, Linux Kernel, Mini Root File
System, and User Root File System partitions.
In order to prevent user applications from crashing the Root File System, UC-7420/7410 uses a
specially designed Mini File System with Protected Configuration for emergency use. This
Mini File System comes with serial and Ethernet communication capability for users to load the
Factory Default Image file. The Mini File System will only be activated if the boot loader fails to
load the User Root File System.
User AP
User Directory
(User Configuration)
Mini Root File System
Configuration
Linux Kernel & Root
HW
Boot Loader
To improve system reliability, UC-7420/7410 has a built-in mechanism that prevents the system
from crashing. The procedure is as follows.
When the Linux kernel boots up, the kernel will mount the root file system, and then enable