Firmware Images
===============

The OpenWrt build for Horst generates several images in directory
trunk_rootdir/bin/ixp4xx. I use

	openwrt-ixdpg425-zImage			(zImage partition)
	openwrt-ixp4xx-generic-squashfs.img	(rootfs partition)

These two images were made available to an tftp server.



Partitioning and Flashing
=========================
Using the fis tool within Redboot, on Horst I deleted all partitions
between (i.e. not including!) the partitions named RedBoot' and
'RedBoot config'

Then I flashed the above mentioned files using these RedBoot commands:

	load -r -b %{FREEMEMLO}  openwrt-ixdpg425-zImage
	fis create zImage

	load -r -b %{FREEMEMLO}  openwrt-ixp4xx-generic-squashfs.img
	fis create rootfs


This is how the partition layout looks like on my Horst:

	RedBoot> fis list
	Name              FLASH addr  Mem addr    Length      Entry point
	<Not a string: 0x3FFF300> 
	                  0x28011301  0x00696E66  0x6F5F636F  0x6E736F6C
	RedBoot           0x50000000  0x0013A400  0x00080000  0x0013A400
	nvram             0x50080000  0x00800000  0x00040000  0x00800000
	zImage            0x500C0000  0x00026400  0x00100000  0x00026400
	rootfs            0x501C0000  0x00026400  0x007A0000  0x00026400
	RedBoot config    0x50FC0000  0x50FC0000  0x00001000  0x00000000
	FIS directory     0x50FE0000  0x50FE0000  0x00020000  0x00000000
	                  0x5F736372  0x69707400  0x00000000  0x0411010C


Note that on the first boot after flashing, OpenWrt automatically allocates
a jffs2 file system in the free space between the 'rootfs' and the
'RedBoot config' partition.

This jffs2 file system is made to overlay (merge with) the readonly
squashfs file system. This is implemented by using an 'overlayfs' file
system, which drives both the squashfs and the jffs2 file systems.

This way the jffs2 file system captures all changes made to the root file
system.

overlayfs is similar to UnionFS. Learn from UnionFS:
http://en.wikipedia.org/wiki/UnionFS

Advantages of this approach:
* The initial root file system (squashfs) is highly compressed (higher than jffs2)
* Any changes to the initial system can be easily saved or identified by looking
  at the content of the jffs2 file system. Very usefull when reflashing/upgrading.



Fconfig settings
================

These are the fconfig settings I use:

	RedBoot> fconfig -l
	Run script at boot: true
	Boot script:
	.. fis load zImage
	.. exec -c "console=ttyS0,57600n8 console=ttyS0 rootfstype=squashfs,jffs2 root=/dev/mtdblock3 redboot.directory=127"

	Boot script timeout (1000ms resolution): 3
	Use BOOTP for network configuration: false
	Gateway IP address: 0.0.0.0
	Local IP address: 192.168.0.23
	Local IP address mask: 255.255.255.0
	Default server IP address: 192.168.0.9
	Console baud rate: 57600
	GDB connection port: 9000
	Force console for special debug messages: false
	Network debug at boot time: false
	Default network device: npe_eth0
	Network hardware address [MAC] for NPE eth0: 0xAA:0xCC:0xCC:0xDD:0xEE:0xFE
	Network hardware address [MAC] for NPE eth1: 0xAA:0xBB:0xCC:0xDD:0xEE:0xFF  
	serial_nr: abcdef012345