This file describes how to create a bootable SD card for the TS-7800, TS-7350, 
TS-7370, or TS-7390, and how to restore the on-board flash to factory default 
for boards that have on-board flash.  Files in this directory:
- 512mbsd-latest.dd.bz2                       SD card image
- initrd-busybox-rootfs-latest.dd             initial ramdisk partition image
- kernel-image-latest.dd                      kernel image
- flash-mbr.dd                                MBR image for the on-board flash
- sd-mbr.dd                                   MBR image for the SD card

CREATING A BOOTABLE SD CARD FROM A TS IMAGE

Image files are found in 
ftp://ftp.embeddedarm.com/ts-arm-sbc/ts-7xxx-linux/binaries/ts-images/ where 
7xxx is the board you are using.  512mbsd-latest.dd.bz2 is the image with the 
most recent software load.  Copy the image to your Linux PC and unzip it.  Put 
your new SD card in the PC.  The SD card can be 512MB or any larger size, 
including SDHC cards.  Then use the dd command to write the image to the SD 
card, for example:

dd if=512mbsd-latest.dd of=/dev/sda

This assumes /dev/sda is the device node for your SD card.  Make sure you write 
to the card itself and not to a partition on an already formatted card.

The bootable SD card has four partitions.  Partition 1 is a VFAT partition 
which is normally empty.  (On 2GB cards from the factory, this partiton 
contains Eclipse tools and documentation.)  Partition 2 contains a raw kernel 
image.  Partition 3 contains the initial ramdisk.  Partition 4 contains the 
Debian root file system.  After writing your SD card with the image, if your 
card is larger than 512MB you can use fdisk to resize partition 4.

It is important to understand that as part of the boot process, the SBC looks 
at the MBR in the first 512 bytes of the SD card for boot code.  So, if you try 
to create an SD card from scratch by creating partitions and copying the 
kernel, initrd, and Debian filesystem to the right partitions, it will not be 
bootable.

If you have changed the initial ramdisk or kernel on your bootable SD card and 
you would like to restore it, you can do so without rewriting the entire card, 
for example:

dd if=kernel-image-latest.dd of=/dev/sda2
dd if=initrd-busybox-rootfs-latest.dd of=/dev/sda3

RESTORING THE FLASH FROM SD CARD

To restore the on-board flash on a TS-7800 or TS-7390 to the factory default, 
create a bootable SD card as described above, install jumper 1 on the board, 
boot to the SD card, and execute the createmtdroot command.

The TS-7350 and TS-7370 do not have on-board NAND flash, so this does not apply 
to them.  The TS-7800 and TS-7390 have 512MB of on-board flash, and the 
partition scheme mirrors the SD card, except there is no VFAT partition.  
Partition 1 is the kernel image, partition 2 is the initial ramdisk, and 
partition 3 is the Debian file system.

The createmtdroot command copies the kernel and initrd to the flash, then 
erases the Debian file system and replaces it with whatever is mounted at 
/mnt/root -- typically the SD card Debian file system.

The createmtdboot command copies the kernel and initrd, but leaves the Debian 
file system intact.

Do not try to write directly to the flash using the dd command, as that will 
not cater to bad flash blocks.  To write a kernel image or initrd image to 
flash directly, use the mtdcopy command.