root/openembedded/zipitZ2BBfiles/fatroot/README-sdcard

To boot from the SD card, a "backflip" is needed 
to be done.  The Zipit Z2 will boot look for, and
run, the z2script.sh.  Manipulation of resident
environment is done, then a HUP is sent to the
init process to force a reboot onto our new rootfs.

You must prepare the SD card for booting OE (OpenEmbedded)
on the Z2. First, you need a media reader working on
your host computer (this development box). You will
need to know what the device is that is found when you
insert the SD card into the media reader.

The way to do this is to login as root, then tail the 
/var/log/messages file, then repeatedly insert and remove
the card, you shoud see something like this:

========= looking at messages ===============
[root@jtag OE-projects]# tail -f -n 0 /var/log/messages
Jan 25 11:04:35 jtag kernel: SCSI device sdh: 1984000 512-byte hdwr sectors (1016 MB)
Jan 25 11:04:35 jtag kernel: sdh: Write Protect is off
Jan 25 11:04:35 jtag kernel: sdh: assuming drive cache: write through
Jan 25 11:04:35 jtag kernel: SCSI device sdh: 1984000 512-byte hdwr sectors (1016 MB)
Jan 25 11:04:35 jtag kernel: sdh: Write Protect is off
Jan 25 11:04:35 jtag kernel: sdh: assuming drive cache: write through
Jan 25 11:04:35 jtag kernel:  sdh: sdh1
Jan 25 11:04:35 jtag kernel: SCSI device sdh: 1984000 512-byte hdwr sectors (1016 MB)
Jan 25 11:04:35 jtag kernel: sdh: Write Protect is off
Jan 25 11:04:35 jtag kernel: sdh: assuming drive cache: write through
Jan 25 11:04:35 jtag kernel: SCSI device sdh: 1984000 512-byte hdwr sectors (1016 MB)
Jan 25 11:04:35 jtag kernel: sdh: Write Protect is off
Jan 25 11:04:35 jtag kernel: sdh: assuming drive cache: write through
Jan 25 11:04:35 jtag kernel:  sdh: sdh1
Jan 25 11:04:35 jtag kernel: SCSI device sdh: 1984000 512-byte hdwr sectors (1016 MB)
Jan 25 11:04:35 jtag kernel: sdh: Write Protect is off
Jan 25 11:04:35 jtag kernel: sdh: assuming drive cache: write through
Jan 25 11:04:35 jtag kernel: SCSI device sdh: 1984000 512-byte hdwr sectors (1016 MB)
Jan 25 11:04:35 jtag kernel: sdh: Write Protect is off
Jan 25 11:04:35 jtag kernel: sdh: assuming drive cache: write through
Jan 25 11:04:35 jtag kernel:  sdh: sdh1
============== snip =========================



As you can see from the above log, with my media
reader, my Linux system sees the SD card as /dev/sdh?
To verify that this is correct, get a list of the
partitions on that suspected card:

========= checking partition table ==========
[root@jtag OE-projects]# fdisk -l /dev/sdh

Disk /dev/sdh: 1015 MB, 1015808000 bytes
32 heads, 63 sectors/track, 984 cylinders
Units = cylinders of 2016 * 512 = 1032192 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sdh1               1         984      991840+   6  FAT16
============== snip =========================



Ok, that is a 1Gig SD (991K) card and it is a FAT16 partition.
That does look like the correct device.  If unsure, just
pop the SD card out of the reader and try the fdisk
command again and you should now get an error message.


Next, edit the prepSDcard.pl script and change:
my $DEVICE = "/dev/sdX";

To what your card is, in my case 'sdh':
my $DEVICE = "/dev/sdh";


The prepSDcard.pl script will do the work for you of
getting a card ready to use to boot Linux on the Zipit Z2.
This script also can be used as a development tool to
update the ext3 partition contents as you go along.


To make a bootable Linux system for the Zipit Z2, have
the fatroot.zip file and the Linux image tarball on
your system, then:

./prepSDcard.pl --partitions --fatroot=zipitZ2BBfiles/fatroot/fatroot.zip --tarball=tmp.zipitZ2/deploy/images/base-image-zipit2.tar

That is all one line. It will partition the card,
format the vfat and ext3 filesystems on the card, then,
will populate the card with the data needed.  Once it
declares "Success", simply put the card in the Z2 and
power it on. The first time you may have to wait a 
minute or two for the firstime configuration to finish.

Subsequent use of the script to replace the ext3 filesystem
contents would be something like this:

./prepSDcard.pl --tarball=tmp.zipitZ2/deploy/images/base-image-zipit2.rootfs.tar

Don't worry, if you have the DEVICE named correctly, then
all should proceed correctly. The script does a number of
checkpoints to avoid problems or to catch errors.

Enjoy! :-)