- Using a web browser, download the image file to the desktop computer. You should end up with a file of the form BBB-eMMC-flasher-distro-YYYY.MM.DD.img.xz.
- Check whether your desktop computer can open the .xz format file. If it cannot, then please see www.7-zip.org for an open-source file archiving tool, which is capable of extracting the .xz format—a lossless data compression format that uses the Lempel-Ziv-Markov Algorithm (LZMA).
- If the archive extraction is successful, the result will be a single file with the .img extension (SD image file) of the form BBB-eMMC-flasher-distro-YYYY.MM.DD.img.
- Under Windows, install “Win32 Disk Imager” from sourceforge.net/projects/win32diskimager/files/latest/download. Extract it to a folder that you can find again in the future, and execute Win32DiskImager.exe directly from within that folder. You will have to “elevate it” by right-clicking and choosing “Run as administrator”. Please note that there is a similar tool for Mac OS X called “Pi Filler”.
- Place a micro-SD card that has sufficient capacity (ideally 4GB+) into your computer’s SD card reader/writer and then start the Disk Imager tool. Once the disk imager software has started, it will not detect the SD card when it is inserted into the computer, so please insert the SD card first. A Class 10 Micro-SD card or greater is preferable.
- Using Win32 Disk Imager, write the .img file to your SD card (using its drive letter for the SD reader on your desktop). This will take some time (about 5–15 minutes), which varies according to card speed, writer speed, and the distribution used. See Figure 2.A1 below for a screen capture of Win32 Disk Imager in action. When you are done, you will have a micro-SD card that you can use to flash your BBB’s eMMC.
Figure 2.A1: The Win32 Disk Imager writing to the micro-SD card.
Desktop Linux Alternative
If you are not familiar with Linux then please ignore this section—it is here for reference. Here are the steps required to create the SD card image on Linux:
- Find the micro-SD Card device (for example, mine is sdd). Type the following:
- Download the flasher image file (get the URL from BeagleBoard.org/latest-images). For example:
$ wget http://debian.beagleboard.org/images/BBB-eMMC-flasher-debian-7.5-2014-05-14-2gb.img.xz
- Decompress the .xz file:
This gives you the image file: BBB*.img. Write the image to the memory card (please check that you have the correct SD card device—in my case it is /dev/sdd)
$ sudo dd if=./BBB*.img of=/dev/sdX
where BBB*.img is the full name of the image file—use the Tab key to autocomplete. /dev/sdX is your specific SD card reader device. It should take 5 to 10 minutes for this write to complete.
Flashing the BBB with the SD Card Image
At this point you should have a micro-SD card containing a “flasher” Linux image. Here are the steps to flash the eMMC:
- You should perform this process with only a single 5V 2A power supply plugged into the DC jack. Alternatively, you can use a USB adapter for power. Disconnect the Ethernet cable and remove any shields and USB peripherals.
- Power off your BBB by physically disconnecting the USB/power cable.
- Plug the micro-SD card into the BBB’s micro-SD card slot.
- Hold the Boot Button (S2) on the top right (near the SD card slot) and, while holding this button, insert the USB/power lead to connect the power. Keep holding the button until the LEDs start to flash. The blue on-board LEDs should light in sequence and then continue to flash for the next 5–25 minutes (depending on the distribution used and the speed of the SD card). The latest distribution flashes in a Cylon/Knightrider pattern.
- Wait until the LEDs stop blinking and all 4 LEDs are fully lit (the latest image then powers the board down). This process can take 5-25 minutes depending on the image used. If the flashing procedure fails—for example, no LEDs flash, or it keeps running for more than 45 minutes —then disconnect the power and try restarting the BBB with the S2 button pressed.
- Remove the micro-SD card. This is important, as you could end up flashing the eMMC again by accident.
- Finally, press the Power button (S3) to power up the board and you should have the latest image installed.