In order to boot the AXP using the xmodem interface when the board fails
to boot and reaches the "trying uart" option in the BootROM, you need to
follow the follwing steps:

	- Start the minicom and make sure the you can see the BootROM printings
	  that end with the line "BootROM: Trying UART"
	- At this stage the board is ready to get a pattern that instructs it 
	  what to do (either start Xmodem or go into a debug shell).
	- To star the Xmodem simply send the "Xmodem_boot_pattern.bin" as ascii
	  (Ctrl+A then s, then select ascii).
	- After sending the file, you should start seeing strange characters on
	  the screen printed once in a second. These are the Xmodem NACKs.
	- This means that you are ready to send the new u-boot with Xmodem (which
	  needs to be with checksum packets and not crc-16 that is used in default
	  Xmodem in minicom).
	- Compile the sx-at91.c file (or you can use my pre-built).
	- Add this binary to the minicom transfer protocols (see instructions in
	  the file sx-at-91.c header). The newly added file should look like:
		| J  sx-at91    <path to sx-at91 file> <serial port> Y    U    N       N       N    |
	  example:
		| J  sx-at91    /home/tawfik/temp/x/sx-at91 /dev/ttyS1 Y    U    N       N       N    |
	- Please note that you need to use the correct path and "tty" device. In my
	  example I have the board connected to /dev/ttyS1.
	- Start the Xmodem transfer through sending the uart boot file
	 (u-boot-2009.08-2.3.2-uart.bin) and selecting the sx-at91 protocol (Ctrl+a
	 then s, select ax-at91)
	- When the transfer finishes, press any key to go back and the u-boot
	  should be loaded.