OMAP Wireless Connectivity AM335x Preparing SD Card

Introduction

The Linux SD card provided with a Sitara AMx EVM may be re-created from the Sitara Linux SDK. This guide describes the process for creating an SD card which be loaded with all the system collateral needed to boot and run a Linux system on the EVM.

The card will have a small (~70M) bootable DOS partition for system binaries (x-loader, u-boot, uImage), and an ext3 partition (~1G) for a Linux root file system. <bg> <bg>

Partition Name	Type	OS	Contents
boot	FAT32	Windows/Linux	Out of Box Demo; windows_user.htm
rootfs	EXT3	Linux	Root File System

Hardware Assumptions

• Linux host machine with available USB ports for an SD card reader (virtual machines work well).
• USB SD card reader
• SD card (at least 4G recommended)

Software Assumptions

• Linux system binaries (x-loader, u-boot, uImage).
• Linux embedded system root filesystem

Preparing an SD Card

The EVM box contains an SD card that is ready-to-use, provided with the up-to-date software for running WLAN and BT demos. However, whenever software upgrade is required, the SD card must be upgraded according to the instructions provided in this section.
To prepare an SD card suitable to boot from, you need to have the following files:

• MLO - addition for u-boot to load from SD card
• u-boot.img - u-boot Linux loader binary
• uImage - image of Linux kernel to be loaded by u-boot
• root file system that will be mounted by board

Steps to be followed to generate a bootable SD card:

1. Enter the SD and check what is the name Linux system provided to the "new device". For example: in Ubuntu distribution running 'sudo fdisk -l' will detail the device-names provided to each disk by the system. Assume that the inserted card got the name /dev/sdc.
2. Partitioning The following procedure would format and partition the SD card with the following partitions:

• make first partition as FAT with label 'boot'
• make second partition as ext3 with label 'rootfs'

The "mkcard-v0.3.sh" shell script can be obtaind from <this> link

sudo umount /dev/sdc1
sudo umount /dev/sdc2
sudo sh ~/mkcard-v0.3.sh /dev/sdc

3. Coping files

• First partion will contain boot files: MLO, u-boot and uImage. The order of the files being copied is significant:

mount /dev/sdc1 /mnt
cp MLO /mnt/MLO
cp u-boot.img /mnt/u-boot.img
cp uImage /mnt/uImage
umount /dev/sdc1

• Second partion will contain root file system to be mounted by Linux on a board:

mount /dev/sdc2 /mnt
sudo tar zxvf some-rootfs.tar.gz -C /mnt
chmod 755 /mnt
umount /dev/sdc2

Now the SD card is ready.