boot sequence on beagleboard-xM?

I understand this is different from the rev C board, but the manual is a bit vague about what actually happens.

Can anyone please point me to some documentation, and/or answer the following:

  • There is no flashable memory on the xM, the boot ROM is fixed forever ?
  • What does the boot ROM have on it? Xloader, Uboot or something lower level?
  • how can I get to a Uboot prompt? The manual says ‘hit a key’. Which key? Any key? it does not work for me.
  • Is it possible to boot from USB as it was on the rev. C, or is SD/MMC the only option?

I would like to boot from a USB memory stick, so if anyone has done that I would be very interested to hear about it.

See below.

Gerald

I understand this is different from the rev C board, but the manual is a bit vague about what actually happens.

Can anyone please point me to some documentation, and/or answer the following:

  • There is no flashable memory on the xM, the boot ROM is fixed forever ?

Fixed forever.

  • What does the boot ROM have on it?

Code specific to the ability to load xloader.

Xloader, Uboot or something lower level?

It loads xloader in the cse of the -xM from the SD card. xloder laods Uboot.

  • how can I get to a Uboot prompt?

Remove the image kernel from the SD card or hit the enter on the keyboard conencted to the serial port before it loads the kernel.

The manual says ‘hit a key’. Which key? Any key? it does not work for me.

Any key will work, but just use the enter key. Just make sure you don’t wait too late. Otherwise you will miss it. experiment with the amount of delay works for you based on how quickly you can get tot he keybaord once you decide to hit the key.

  • Is it possible to boot from USB as it was on the rev. C, or is SD/MMC the only option?

You can only boot form SD or the serial port.

I would like to boot from a USB memory stick, so if anyone has done that I would be very interested to hear about it.

Sorry. No can do. ROM does not support memory stick loading.

Gerald,

thank you very much, that is a great help.

I think the reason I can’t get the boot prompt is because I do not have the keyboard on the serial port. I have it on a USB port. That works fine with Linux, but I guess it is not recognised until Linux boots, and so is no good at boot time.

(I am using the serial port to receive data from a laser rangefinder, and using USB mouse and keyboard, and ssh over the ethernet to drive the BB)

The xM setup does seem rather less flexible than the the C board, though. I guess there is a reason behind that.

cheers

Gareth

If you want a terminal output and control, then yes it has to be connected to the serial port. UNtill LInux comes up ther USB ports do not work.

As to flexability versus the BeagleBoard., both boards work the same in this regard.

Gerald

Some of the documentation says that USB is is in the boot sequence, e.g. Illustration 2 of Introduction to BeagleBoard http://www.teslabs.com/wp-content/uploads/2010/02/beagleboard.pdf Is that an even older version of BB?

thanks again

Gareth

hi all
beagle board xm rev c with linux kernel 3.4.0 running (sd boot)

arm9-mini2440.blogspot.in
http://www.youtube.com/watch?v=zJVJ9gXj3Wk&feature=plcp

working on bsp for lcd on same kernel.
For any queries reply me.

best wishes
Phanirajkiran.
Embedded Software Labs – Hyderabad .
mprk@embeddedsoftwarelabs.com
India.

That is USB client. NOT USB Host, which is required for a Thumbdrive. Client mode only is supported.

Gerald