Moxa UC-8481-LX [7/90] Additional information about jffs2 is available on the following websites

Moxa UC-8481-LX [7/90] Additional information about jffs2 is available on the following websites
UC-8410/8416/8418/8430 Introduction
1-3
and then enable services and daemons. During this 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, providing a “safe” zone.
For more information about memory map and programming, refer to Chapter 5, Programmers Guide.
Journaling Flash File System (JFFS2)
The User Root File System 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, 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 (which
enhances 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:
Targets the Flash ROM directly
Robustness
Consistency across power failures
No integrity scan (fsck) is required at boot time after normal or abnormal shutdown
Explicit wear leveling
Transparent 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 after 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 on the following websites:
http://sources.redhat.com/jffs2/jffs2.pdf
http://developer.axis.com/software/jffs/
http://www.linux-mtd.infradead.org/
Software Features
Linux
Kernel Version: 2.6.23
Protocol Stack:
TCP, UDP, IPv4, SNMP V1, ICMP, ARP, HTTP, CHAP, PAP, SSH 1.0/2.0, SSL, DHCP, NTP, NFS,
Telnet, FTP, PPP, PPPoE, OpenVPN
File System: JFFS2, NFS, Ext2, Ext3
System Utilities: bash, busybox, tinylogin, telnet, ftp, ssh, scp
telnetd: telnet Server daemon
ftpd: FTP server daemon
sshd: secure shell server
Apache: web server daemon, supporting PHP and XML

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