7 Replies Latest reply on Mar 13, 2019 8:46 PM by mp2100

    eMMC Flash Storage and microSD Card Boot on BeagleBone

    ninjatrent

      Hi BeagleBoard Community,

       

      I have a few questions with regards to the boot sequence of the BeagleBone Black Wireless and BeagleBone Blue.

       

      By default, Does the BeagleBone boot from the eMMC flash or from the image on the microSD card?

       

      Does the SD Boot button on the Beagle need to be depressed each time in order to boot from the microSD card?

       

      Is there support for microSD cards larger than 32GB?

       

      Thanks for your time.

       

      Trent

        • Re: eMMC Flash Storage and microSD Card Boot on BeagleBone
          mp2100

          Trent,

          When I read the beaglebone black documentation, it was my understanding that the boot button had to be pressed every time you wanted to use the SD card to be the boot device.  That has not been my experience though.  I have been booting from the SD card because it has the latest operating system.  (I haven't bothered burning it to the eMMC chip).  I had to press the boot button the first time I wanted to use the SD card.  After that, it always booted from the SD card, without me pressing the boot button.  It seems like it's a latching button.

           

          I was thinking I should try removing the SD card, and seeing if that stopped the latching.  But it's on my long list of mysteries to solve.

           

          Allen

          2 of 2 people found this helpful
            • Re: eMMC Flash Storage and microSD Card Boot on BeagleBone
              ninjatrent

              Hi Allen,

               

              It seems like the eMMC boots without the sd to an outdated iot image that was previously installed. I origally flashed the eMMC on both my Black Wireless and Blue with the beagleboard debian iot image. When booting from the microSD, I've always held the sd boot button. I didn't know if it was possible to boot from sd without holding the button down.

              Trent

                • Re: eMMC Flash Storage and microSD Card Boot on BeagleBone
                  mp2100

                  In case anyone really wanted to know the answer, I ran some tests today.  Yes, the Boot button (which lets you boot from the SD card instead of the on-board eMMC memory) is "latching".  (All this was done with $sudo shutdown now) More latching that I expected:

                   

                  -boot with no SD card                                                   -boots from eMMC (of course)

                  -SD card, hold Boot button briefly while power it up     -boots from SD card

                  -power down, then up,don't hold Boot button               -boots from SD card  (so it's latching)

                   

                  Then I immediately tried this:

                  -then remove SD card, power on                      -boots from eMMC (of course)

                  -power down, then up, don't hold Boot button  -still latched from previous, boots from SD card

                  much to my surprise, it latches even after having a reboot with the SD card removed.

                   

                  As an aside, all this rebooting showed me that the eMMC  memory is much faster than the SD card access.  I'm using the clever USB/ethernet connection to 192.168.7.2, and Cloud9 IDE and other apache pages display much faster when using the eMMC.

                  2 of 2 people found this helpful
                    • Re: eMMC Flash Storage and microSD Card Boot on BeagleBone
                      ninjatrent

                      Hi Allen,

                       

                      Thank you for for testing this. The boot procedure was a bit confusing at first but you have clarified how the BeagleBone is handling the the microSD.

                      So I've made the error of holding the boot button every time I wanted to run the image from the microSD.

                      1 of 1 people found this helpful
                      • Re: eMMC Flash Storage and microSD Card Boot on BeagleBone
                        shubham1997

                        Hi Allen,

                        1. Please let me the which image did you flashed and did you flashed using external power source?2. If now Beaglebone black is flashed using SD card and as you say it boots everytime you power it on with SD card inserted, can use use the SD card for storage? If yes then please let me know how.

                        3. Can you provide the documentation or its link you reffered?

                        4. If you know how to execute a specific custom program eg. Pattern of LED lights on GPIO once Beaglebone boots, just like Arduino. How can we do that?

                         

                        Thanks

                          • Re: eMMC Flash Storage and microSD Card Boot on BeagleBone
                            mp2100

                            Hmmm, good questions.  I should document my testing more thoroughly.

                             

                            For which image, I used the newest image from beagleboard:

                                 BeagleBoard.org - latest-images

                                 At this time the latest is named    Debian 9.5 2018-10-07 4GB SD LXQT 

                             

                            I did not use the external power source, I connected the BBB using a USB cable to my Linux laptop, and used the included Cloud9 interface to communicate with the BBB (web browser at 192.168.7.2:3000)

                             

                            I did use a 16 GB SD card with the 4 GB image from beagleboard.org.  I expanded the image so I could use the full 16 GB, so yes, that gives me more storage.  But is your question about using the SD card as external storage instead of a boot device?  If yes, then I would answer that I'd put a USB flash drive into the BBB USB port for that purpose.

                             

                            For automatically executing a script to illuminate a pattern of LEDs, one answer for the BBB is to use the node.js feature built into the cloud9 IDE.  There is an autorun folder, and when you copy a node program into there, it will run at boot up.  Wire the LEDs to the plentiful GPIO on the beaglebone, test your node.js program, and copy it there when ready.

                             

                            1 of 1 people found this helpful