U-boot musb gadget support

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The code for musb gadget support is currently available on the omap3-dev-usb branch of the Beagle U-Boot git repository.

Current Status

  • Currently the code enables the Beagleboard to be recognized as a USB ACM modem, and provides a u-boot console over it. However some issues with initialization need to be solved (see Known bugs section).

Known bugs

  • Setting the stdint,stdout,stderr to be multi-io (have the u-boot console and serial and USB at the same time) gets stuck if a terminal like minicom isn't open on the USB ACM device.

Next steps

  • Fix the problem with multi-io

Getting the source code

Checkout the git source for the musb gadget support from the Beagle U-Boot git repository. Get it by:

git clone git://www.sakoman.net/git/u-boot-omap3.git
cd u-boot-omap3
git checkout --track -b omap3-dev-usb origin/omap3-dev-usb

Build (assuming Code Sourcery GCC 2007q3):

make CROSS_COMPILE=arm-none-linux-gnueabi- mrproper
make CROSS_COMPILE=arm-none-linux-gnueabi- omap3_beagle_config
make CROSS_COMPILE=arm-none-linux-gnueabi-

Getting started

  • Load your new u-boot.bin image into the board using any of the existing methods. If you have a beagle running already a working u-boot, you can load it by serial using the 'loady' command and minicom or 'sb' (be sure to have lszrz installed in your distro). Then erasing the u-boot in flash and reflashing the new image with the following commands:
nand unlock
nand erase 80000 160000
nand write.i 80000000 80000 160000
  • Reboot your board and keep the user button pressed while applying power (see Known bugs).
  • Attach a mini-b USB cable to the beagle. Your host should recognize an ACM CDC device (works out of the box on Linux and OS X).
  • If you want to have the u-boot console over USB use the following command:
setenv stdout usbtty; setenv stdin usbtty; setenv stderr usbtty
  • You can also use multi-io to have the console over serial and USB at the same time, but this has a bug documented in Known bugs:
setenv stdout usbtty,serial; setenv stdin usbtty,serial; setenv stderr usbtty,serial