=================
 Files Included:
=================
./binaries/ts-scripts/linuxrc-mtdroot-readonly
   -- The linuxrc script that will boot automatically to MTD filesystem as readonly

./binaries/ts-scripts/linuxrc-sdroot-readonly
   -- The linuxrc script that will boot automatically to SD filesystem as readonly

./binaries/ts-kernels/Image-oct102010-readonly
   -- The raw Linux kernel image with unionfs symbols compiled 

./binaries/ts-images/512mbsd-oct102008-readonly.dd.bz2
   -- The full 512MB SD card image with all readonly components included

./binaries/ts-images/initrd-busybox-rootfs-oct102008-readonly.dd
   -- The initial ramdisk (initrd) image with linuxrc*readonly and unionfs.ko module

./binaries/ts-images/kernel-image-oct102008-readonly.dd
   -- The raw Linux kernel image with unionfs symbols compiled 

./distributions/initrd-busybox-rootfs-oct102007-readonly.tar.gz
   -- The initial ramdisk (initrd) filesystem with linuxrc*readonly and unionfs.ko module

./docs/ts-7800-readonly-readme.txt
   -- This readme

=================
Introduction
=================
The readonly image is provided in hopes that it will be of use to our
customers.  In order to make the TS-7800 even more robust against power
outages and filesystem corruption, a readonly filesystem can be used.
Please see our whitepaper entitled "Preventing Filesystem Corruption in
Embedded Linux" which can be found here:
	
	http://www.embeddedarm.com/about/resource.php?item=459

Creating this image was a matter of adapting the TS-7350 Read-Only Guide
to fit the crosstool/kernel of the TS-7800.  If you would like to try
and reproduce compiling unionfs support on your own board (for fun?),
use the following two guides:

	1.) "TS-73XX Read-Only Debian"
	   -- http://www.embeddedarm.com/about/resource.php?item=466
	2.) "TS-7800 Kernel Compile Guide"
	   -- http://www.embeddedarm.com/about/resource.php?item=412

=================
Usage:
=================
There are three major components to making your system
readonly:

	1.) The unionfs.ko module (unionfs.ko)
	2.) The kernel in which unionfs.ko was compiled against (readonly-Image.dd)
	3.) The linuxrc-mtdroot-readonly and/or linuxrc-sdroot-readonly files (readonly-initrd.tar.gz)

If you would like to boot from NAND flash, you will need to first boot
from SD card (512mb-ts7800-readonly.dd) and then issue the 'createmtdboot'
command to copy the initrd and kernel to the onboard NAND flash.  Remove
the SD card, boot to NAND flash, and create a symlink with the command:

	ln -sf linuxrc-mtdroot-readonly linuxrc; save

If you would like to boot from SD card, simply boot to the SD card and create a symlink with the command:

	ln -sf linuxrc-sdroot-readonly linuxrc; save

Now, when you boot the TS-7800, it will automatically boot to either the
MTD root or SD root, depending on what you setup from above, and it will
be readonly.  None of the changes you apply to the filesystem will be
persistant on restart.  Here is an example dialog of the bootup sequence:

	>> TS-BOOTROM - built Dec  4 2008
        >> Copyright (c) 2008, Technologic Systems
        >> Booting from onboard NAND flash...
        .
        .
        .
        .
        >> Booting to MTD (Read-Only)...

Please refer to the following guide for
more information:
	
	http://www.embeddedarm.com/about/resource.php?item=459

=================
Document Info
=================
Engineer: Derek Hildreth
Date: June 10, 2010
Comments:
   Initial release of ts-7800-readonly-readme on FTP site