Setup sdcard for beagleboard xm

SD card setup

(For a BeagleBoard xM specific step-by-step guide to setting up your SD card and installing Angstrom, click here->http://www.slimlogic.co.uk/2011/05/omap3-sd-booting/ )

Now we want to use an SD card to install some GNU/Linux distro in it and get more space for our stuff. You can use either an SD or SDHC card. In the latter case of course take care that your PC card reader also supports SDHC. You should know that you are not dealing with an x86 processor, this is a completely different architecture called ARM, so don't even try to install a normal distro here.

Since the steps for getting this to work are already written down in the wikis, I'll copy the information, pointing out some extra things you should take care of.

First of all, we want to set up the SD card to be used as a boot disk, let's plug it into our PC card reader and see what the wiki page says:

MMC boot format

In order to create a bootable SD/MMC card under Linux compatible with OMAP3 boot ROM, you have to set a special geometry in the partition table. There are two ways of doing this, with a script or, through the fdisk "Expert mode".

Formatting the SD card via the mkcard.txt script

Download mkcard.txt from here.
http://www.slimlogic.co.uk/2011/05/omap3-sd-booting/

$ chmod +x mkcard.txt
$ sudo ./mkcard.txt /dev/sdx, Where x is the letter of the card. You can find this by inserting your card and then running dmesg | tail. You should see the messages about the device being mounted in the log. Mine mounts as sdc.
Once run, your card should be formatted.

Formatting the SD card via fdisk "Expert mode"

First, lets clear the partition table:

================================================================================
$ sudo fdisk /dev/sdb

Command (m for help): o
Building a new DOS disklabel. Changes will remain in memory only,
until you decide to write them. After that, of course, the previous
content won't be recoverable.

Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
================================================================================
Print card info:

================================================================================
Command (m for help): p

Disk /dev/sdb: 128 MB, 128450560 bytes
....
================================================================================
Note card size in bytes. Needed later below.

Then go into "Expert mode":

================================================================================
Command (m for help): x
================================================================================
Now we want to set the geometry to 255 heads, 63 sectors and calculate the number of cylinders required for the particular SD/MMC card:

================================================================================
Expert command (m for help): h
Number of heads (1-256, default 4): 255

Expert command (m for help): s
Number of sectors (1-63, default 62): 63
Warning: setting sector offset for DOS compatiblity
================================================================================
NOTE: Be especially careful in the next step. First calculate the number of cylinders as follows:

B = Card size in bytes (you got it before, in the second step when you printed the info out)
C = Number of cylinders
C=B/255/63/512
When you get the number, you round it DOWN. Thus, if you got 108.8 you'll be using 108 cylinders.

================================================================================
Expert command (m for help): c
Number of cylinders (1-1048576, default 1011): 15
================================================================================
In this case 128MB card is used (reported as 128450560 bytes by fdisk above), thus 128450560 / 255 / 63 / 512 = 15.6 rounded down to 15 cylinders. Numbers there are 255 heads, 63 sectors, 512 bytes per sector.

So far so good, now we wanna create two partitions. One for the boot image, one for our distro. Let's check what another wiki page has to say about it:

Linux boot disk format

Create the FAT32 partition for booting and transferring files from Windows. Mark it as bootable.

================================================================================
Expert command (m for help): r
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-245, default 1): (press Enter)
Using default value 1
Last cylinder or +size or +sizeM or +sizeK (1-245, default 245): +50

Command (m for help): t
Selected partition 1
Hex code (type L to list codes): c
Changed system type of partition 1 to c (W95 FAT32 (LBA))

Command (m for help): a
Partition number (1-4): 1
================================================================================
Create the Linux partition for the root file system.

================================================================================
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 2
First cylinder (52-245, default 52): (press Enter)
Using default value 52
Last cylinder or +size or +sizeM or +sizeK (52-245, default 245):(press Enter)
Using default value 245
================================================================================
Print and save the new partition records.

================================================================================
Command (m for help): p

Disk /dev/sdc: 2021 MB, 2021654528 bytes
255 heads, 63 sectors/track, 245 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/sdc1 * 1 51 409626 c W95 FAT32 (LBA)
/dev/sdc2 52 245 1558305 83 Linux

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error 16: Device or resource busy. The kernel still uses the old table. The new table will be used at the next reboot.

WARNING: If you have created or modified any DOS 6.x partitions, please see the fdisk manual page for additional information.
Syncing disks.
================================================================================
Now we got both partitions, next step is formatting them.

NOTE: If the partitions (/dev/sdc1 and /dev/sdc2) does not exist, you should unplug the card and plug it back in. Linux will now be able to detect the new partitions.

================================================================================
$ sudo mkfs.msdos -F 32 /dev/sdc1 -n LABEL
mkfs.msdos 2.11 (12 Mar 2005)

$ sudo mkfs.ext3 /dev/sdc2
mke2fs 1.40-WIP (14-Nov-2006)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
195072 inodes, 389576 blocks
19478 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=402653184
12 block groups
32768 blocks per group, 32768 fragments per group
16256 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912

Writing inode tables: done
Creating journal (8192 blocks): done
Writing superblocks and filesystem accounting information:
================================================================================
All done!

NOTE: For convenience, you can add the -L option to the mkfs.ext3 command to assign a volume label to the new ext3 filesystem. If you do that, the new (automatic) mount point under /media when you insert that SD card into some Linux hosts will be based on that label. If there's no label, the new mount point will most likely be a long hex string, so assigning a label makes manual mounting on the host more convenient.

#! /bin/sh
# mkcard.sh v0.5
# (c) Copyright 2009 Graeme Gregory <dp@xora.org.uk>
# Licensed under terms of GPLv2
#
# Parts of the procudure base on the work of Denys Dmytriyenko
# http://wiki.omap.com/index.php/MMC_Boot_Format

export LC_ALL=C

if [ $# -ne 1 ]; then
echo "Usage: $0 <drive>"
exit 1;
fi

DRIVE=$1

dd if=/dev/zero of=$DRIVE bs=1024 count=1024

SIZE=`fdisk -l $DRIVE | grep Disk | grep bytes | awk '{print $5}'`

echo DISK SIZE - $SIZE bytes

CYLINDERS=`echo $SIZE/255/63/512 | bc`

echo CYLINDERS - $CYLINDERS

{
echo ,9,0x0C,*
echo ,,,-
} | sfdisk -D -H 255 -S 63 -C $CYLINDERS $DRIVE

sleep 1


if [ -x `which kpartx` ]; then
kpartx -a ${DRIVE}
fi

# handle various device names.
# note something like fdisk -l /dev/loop0 | egrep -E '^/dev' | cut -d' ' -f1
# won't work due to https://bugzilla.redhat.com/show_bug.cgi?id=649572

PARTITION1=${DRIVE}1
if [ ! -b ${PARTITION1} ]; then
PARTITION1=${DRIVE}p1
fi

DRIVE_NAME=`basename $DRIVE`
DEV_DIR=`dirname $DRIVE`

if [ ! -b ${PARTITION1} ]; then
PARTITION1=$DEV_DIR/mapper/${DRIVE_NAME}p1
fi

PARTITION2=${DRIVE}2
if [ ! -b ${PARTITION2} ]; then
PARTITION2=${DRIVE}p2
fi
if [ ! -b ${PARTITION2} ]; then
PARTITION2=$DEV_DIR/mapper/${DRIVE_NAME}p2
fi


# now make partitions.
if [ -b ${PARTITION1} ]; then
umount ${PARTITION1}
mkfs.vfat -F 32 -n "boot" ${PARTITION1}
else
echo "Cant find boot partition in /dev"
fi

if [ -b ${PARITION2} ]; then
umount ${PARTITION2}
mke2fs -j -L "Angstrom" ${PARTITION2}
else
echo "Cant find rootfs partition in /dev"
fi

To run this script you will require to run it as root. On Ubuntu or other linux with sudo setup run the script as

sudo sh omap3-mkcard.sh /dev/sdX

replacing sdX with the base device name of your SD card device.

If your running a distribution without sudo setup then become root then run the script as

su -
sh omap3-mkcard.sh /dev/sdX