Flash disk cloning

SMR Flash Disk Cloning

New in 2011 version

In order to support both VIA Nehemiah and Intel Atom based platforms two kernels must be included in the smr flash image.

• 2.6.32.20-rtai supports multicore systems and hyperthreading
• 2.6.32.20-rtai-up supports single core systems and is optimized to the Via processors

A new clone script called multiclone must be used when this image is flashed. The script is in the root folder of rt15.

Flash cloning procedure on rt15

Via processors using CF-card flash-disks:

• Log in as root (If you don't know the password abort immediately)
• Insert the CF-card in the reader in the front of rt15.
• Check the device name the card is given: tail /var/log/messages. Usually it is /dev/sdb.
• Go to the image folder: cd image
• Locate the image you would like to burn (usually the newest one), for instance: flash-2011-01-01.tgz
• Start the procedure:

root@rt15:~# ../multiclone flash-2011-01-01.tgz /dev/sdb via

NB: Note the two dots in front of multiclone

The procedure for cloning Intel Atom images is the same, except atom must be stated last in stead of via as in:

root@rt15:~# ../multiclone flash-2011-01-01.tgz /dev/sdb atom

Old description

Some of the SMR's now have solid-state flash memory disks, instead of the laptop, 2.5" disks used on older models.

This wiki page contains some notes describing how to write a bootable flash disk image (Slackware Linux) to a memory card. It assumes a Linux PC with USB flash card reader/writer, available as /dev/sda.

The commands below is implemented in this script Clone script. Usage:

clone <from_file.tar.gz> <to device>

<to device> can be both the USB bus (/dev/sdx) or a IDE device (/dev/hdx)

The script will place a file .cloned-at on the Flash Disk with time information for the cloning.

If you put the Flash Disk on the IDE bus and the computer will not boot (LILO - Timestamp mismatch) then the MBR on the Flash Disk must be erased as follows:

dd if=/dev/zero of=/dev/hdx bs=1 count=512

Writing an image

Format the disk, with one large Linux partition:

sfdisk -L /dev/sda <<EOF
,,L,*
EOF

Create a filesystem:

mke2fs /dev/sda1 -L /

Mount the new, empty partition:

mkdir -p /tmp/u
mount /dev/sda1 /tmp/u

Write a previously created image from flash.tar.gz

zcat flash.tar.gz |
tar --extract --file - --directory /tmp/u --preserve-permissions

Create a patched lilo.conf, so that we can run LILO with the flash card mounted via USB. (This won't be necessary if the image written above already contains such a file.)

patch -o /tmp/u/etc/lilo_usb.conf /tmp/u/etc/lilo.conf <<EOF
*** /tmp/u/etc/lilo.conf        Tue Nov  4 21:34:44 2003
--- lilo_usb.conf       Thu Dec 11 11:50:55 2003
***************
*** 4,6 ****
  # Start LILO global section
! boot = /dev/hda
  message = /boot/boot_message.txt
--- 4,7 ----
  # Start LILO global section
! boot = /dev/sda
! disk = /dev/sda bios=0x80
  message = /boot/boot_message.txt
EOF

Run LILO:

chroot /tmp/u lilo -v -C /etc/lilo_usb.conf

All done:

umount /dev/sda1
eject /dev/sda

Reading an image

Mount as above:

mkdir -p /tmp/u
mount /dev/sda1 /tmp/u

Read the partition:

tar --create --file - --directory /tmp/u --one-file-system --exclude lost+found . |
gzip > flash.tar.gz

or

tar -zcf - -C /tmp/u --one-file-system --exclude lost+found . > flash.tar.gz

All done:

umount /dev/sda1
eject /dev/sda