Creating a bootable microSD card

The Overo board will boot directly from a properly prepared microSD card. This section will outline how to partition and format a bootable microSD card. In order to create a bootable microSD compatible with the OMAP3 boot ROM, the SDK automatically format the SD and save the necessary images in the correct partitions.

This example will show the steps for setting up a 2GB microSD card.

Verify your SD CARD is working

First insert your card into your development machine's flash card slot. You may need to use a microSD to SD card adaptor to fit your slot. You can use 'mount' or 'df' to see where the card mounts on your machine.

$ df
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/sda1            234521212  35058568 187549648  16% /
none                   1009920       372   1009548   1% /dev
none                   1014140      1940   1012200   1% /dev/shm
none                   1014140       124   1014016   1% /var/run
none                   1014140         0   1014140   0% /var/lock
none                   1014140         0   1014140   0% /lib/init/rw
                    
/dev/sdd1                39497      4916     34582  13% /media/boot
/dev/sdd2              1857948     93928   1669640   6% /media/rootfs

Set the correct options installer

The option (/dev/sdd) SD device could vary , and its depends on each PC and SD card. The option (/dev/ttyUSB0) Serial port for target communication allow the pc to have a console running on the target. The options Create and format the SD partitions (FAT and Ext3) , allow the SDK format the SD card and create two partitions A FAT partition: I'll have the bootloader , xloader and kernel images

A linux partition (Ext3) to 
  [*]   Create and format the SD partitions (FAT and Ext3)                           
                    Bootloader destination (Flash)  --->                                         
                    Kernel destination (SD)  --->                                                
                    File System destination (SD)  --->     

There are three files required on the first (FAT) partition to boot your Overo:

MLO:

the boot-loader loader - this small program is loaded into the OMAP3 processor's static RAM. It does some minimal configuration of system memory and io pins and then loads the second file.

u-boot.bin

the boot loader image 

At a minimum an embedded bootloader provides the following features:

• Initializing the hardware, especially the memory controller.
• Providing boot parameters for the Linux kernel.
• Starting the Linux kernel

uImage:

The linux kernel

You can build these yourself and download pre-built images. or use the SDK installer. It is important that these three files have precisely these names. , but the SDK installer automatically set those names.