Frequently Asked Questions

The latest community generated FAQ is at http://elinux.org/BeagleBoardFAQ. Below are some answers to the top questions out of that FAQ.

General Questions

1. What is the BeagleBone?
   • A new BeagleBoard.org product targeting hardware expansion, easier cloning and being more affordable
   • Please visit the BeagleBone page for more details.
2. What is the BeagleBoard-xM?
   • A revision of the original BeagleBoard with extra MHz (1GHz), extra memory (currently 512MB), and an on-board USB hub with Ethernet
   • Please visit the xM product details page for more details on the BeagleBoard-xM

Getting support using IRC and the mailing list

1. What is the best way to get my question(s) answered?
   • Search the related websites and mailing list to see if anyone has already asked your question and gotten an answer.
   • Visit the IRC channel for interactive support from your fellow community members. Please be patient as this is an all volunteer effort and people might not be paying attention when you type your question. Try at a few different times of the day and be sure to stay logged in to see any responses. Being polite will help you. You don't need to ask if you can ask a question, just ask :). If you have a large amount of text to share, please use a tool like pastebin.
   • If you still cannot get an answer to your question, try posting it to the mailing list. There are many more people there, which means you should be even more polite and brief. Please give background on what you are trying to do as well as all pertinent information about what results you are seeing, but don't make people read your life's story to be able to help you, because they are not likely to answer if they must read a lot of extraneous information. It is best to follow typical guidelines for asking questions to hackers. Again, this is an all volunteer effort.
   • If you still aren't getting an answer and you really need support, it is suggested you begin shopping for a commercial operating system vendor that can provide you with system support. Please visit the TI Third Party Network and OMAP/Sitara/DaVinci/Integra Support and Training Resources. Feel free to make queries for paid support on the mailing list as well. If you are ready to begin a design with the OMAP35x, you may also contact TI for help in identifying third party design support, but please remember that the Beagle Board is not a TI-supported product and they may recommend that you purchase at TI EVM to be able to answer your queries.

USB related

1. Why doesn't my BeagleBoard or BeagleBoard-xM work when I power it over USB?
   • The first and primary reason is that the validation image shipped with the board today is based on a 2.6.32 kernel with a bug in the USB interrupt management. This bug has been fixed on newer kernels, but those kernels have not yet been added to the BeagleBoard's validation image. A patched version of the 2.6.39 kernel is currently being implemented to support BeagleBoard validation and this bug is expected to go away.
   • A secondary reason is that the default boot condition of the kernel is to power up peripheral interfaces like the EHCI-based USB host on the xM and DVI-D on both pre-xM and xM boards. The USB specification requires devices to power up under 100mA (~500mW) and the USB hub circuit on the BeagleBoard-xM may consume around 100mA itself. Modification is required to the kernel to avoid powering up this section of the board until sufficient current is confirmed by the software. In practice, most host machines will provide sufficient power, despite this violation of the specification. You should consider your power requirements before attempting to utilize USB to power your BeagleBoard or BeagleBoard-xM.
2. How can I get the OTG port working in host mode?
   • There is a jumper on the back of the board that you can blob some solder on or you can use a cable that has the pins shorted. You can read more about this in the System Reference Manual at http://beagleboard.org/hardware/design

Serial port related

1. Why am I not getting output or not able to type into the serial port?
   • For a non-xM board, buy the recommended serial adapter. Unlike earlier versions, the xM boards utilize a straight-through DB9 male-to-female serial cable.
   • Ensure that you are connecting:
     RX to pin 2
     TX to pin 3, and
     GND to pin 5.
   • Follow the steps outlined by the community FAQ and the system reference manual.
2. I built my own custom kernel but I don't see any boot messages?
   • You may be passing the wrong bootargs to the kernel. Linux kernels >= 2.6.36 are using ttyOn instead ttySn for the serials on OMAP, so set console=ttyO2,115200n8 in U-boot.

Software

1. Is BeagleBoard.org Linux only?
   • Beagle Board as such is not associated to Linux only.
   • BeagleBoard.org gives links and pointers (including source) for data related to Beagle. If someone has done good work on Beagle with a propriety OS, we will give links to their site from BeagleBoard.org, it’s left to them if they want to open their source or not.
2. What software can be downloaded directly from BeagleBoard.org?
   • Software is not generally hosted directly on BeagleBoard.org. Instead, a diagnostic image is hosted on http://code.google.com/p/beagleboard and pointers are given to projects that provide additional Beagle software via the projects page.
   • The kernel at http://code.google.com/p/beagleboard is called "diagnostic" because this kernel is just used as reference to check out the board. New development should be done against the linux-omap git tree kernel.
3. I built my own kernel from mainline, but a particular function doesn't seem to work, what do I do?
   • There are certain patches required to make the kernel aware of different types of boards and configure the chips properly. Some of these patches are not merged into mainline for various reasons. These patches are automatically applied when you build a kernel for beagleboard with OpenEmbedded. You can use quilt to apply these patches to your kernel .
4. Can I do feature X with my beagleboard on Linux?
   • Yes, you could possibly do anything you would normally to with a regular Linux system. The BeagleBoard is just like a any other machine.

Miscellaneous

1. Why is there no Ethernet port?
   • Because it can be easily added via USB, but that has now been done on the xM boards for a small additional increase in cost.
2. How do I connect a keyboard and mouse?
   
   • If you are attempting to do so via the OTG port, be certain that you are using a mini- A to standard-A USB adapter. Mini-B adapters will not work without additional hardware modifications. Recommended peripherals can be found on the product details page.
   • It is also necessary to build support for USB OTG host mode into your kernel.
   • The port can only supply 100mA, so you might need a powered hub for power-hungry keyboards and mice
3. What do I need to do to get my software running on a BeagleBoard-xM rev C?
   • The revision ID on the board and the control signal for powering the USB hub on the board changed between xM rev B and xM rev C. Older versions of x-loader/MLO, u-boot and the Linux kernel did not properly utilize the revision ID settings on the board, so xM rev B boards didn't actually include settings different than xM rev A to work-around the issue. On xM rev C, with the USB hub changes on the board, it became necessary to no longer use this work-around and to actually change the board revision ID. This causes older software to break. There is a bit more discussion on this on the mailing list.
   • If you utilize the latest mainline x-loader ( gitorious.org/x-loader ) and u-boot ( git.denx.de/?p=u-boot.git ), including the variations shipped on the microSD card on the board (available at circuitco.com/support ), the revision will be properly detected.
   • The mainline kernel does not yet include the patch required to utilize the proper polarity for the USB hub power enable. You can take a look at this candidate patch for an idea of what to fix and potentially apply this patch to your kernel. If you assemble an image of Angstrom using Narcissus, you'll get a working kernel using the sources in Open Embedded.