Talk:BeagleBone Black Extracting eMMC contents

with some BBB's we have no problem restoring an older angstrom image with dd (Angstrom image uncompressed is 2.1GB) . Image was creating with dd from running system.However,, anyone know why even using this script that some fail with "dd: writing '/dev/mmcblk1': No space left on device" . Yes, the image is compressed as well. Is the only option to recreate the iamge and bring the image down to < 2 GB ? Its just odd that it restores the image on some devices w/out issue.

Jeddonix (talk)

You need to try to keep the format of the eMMC under 2GB to make sure you can replicate it. As long as that is true, the error should be harmless.

Jkridner (talk)

Thank you. Worked beautifully. And so simple!

PaulRyan (talk)

I have tried this procedure but my Beaglebone Black (BBB) does not boot from the microSD, just from the on-board eMMC. I have limited experience with Linux-based systems and so i am sure I am doing, or not, something simple. I am using a rev A5C BBB with a 4GB FAT32 micrSD. Any pointers will be gratefully received. JohnG

Jgainsborough (talk)

I'm having the same issue as jgainsborough.

I formatted a 4GB SDHC as FAT32, extracted the zip to it, inserted into powered-off BBB, held down USER/BOOT applied power, and waited. Never saw any lights other than the power light. Have tried many times, holding down USER/BOOT for as long as 30 seconds.

Have tried with USB and with power supply. Same behavior. Board boots runs fine from internal memory.

Michael.f.ellis (talk)

The page neglects to mention that the partition on the SD must be marked active in order to be booted from when you hold down the USER/BOOT button.

SaintGimp (talk)

You can mark an SD partition active by following: http://www.kozio.com/blog/how-do-i-make-an-sd-card-partition-active-under-windows-7

Jhassell (talk)

I had to hold down the S2 (USER/BOOT) button near the microSD card, while applying power to the board (by plugging in USB cable) in order to boot this firmware and extract the eMMC image. Pressing RESET while holding the S2 button did not work. After several seconds, I released the S2 button and then the LEDs started blinking. It seems the boot sequence doesn't proceed while S2 is being held down.

Edit: A further test shows that holding the S2 button for too long (15+ seconds) causes the board to turn off.

Note: I just formatted the card with FAT32 and copied the files to it. I did NOT mark the partition as 'active', but DID have to hold down the S2 button when applying power.

PausingReality (talk)

Wish I'd noticed all these comments earlier. When in doubt, you might drop a note to http://beagleboard.org/discuss.

Jkridner (talk)

First, thanks for this incredibly useful tool - I use it all the time! I recently got some Rev. C boards from Element14 and the tool stopped working. It appears to be a change in the U-Boot.img on the EMMC. If you are having this problem and save-emmc isn't loading automatically when you insert the SD card you may be able to work around it by mounting the card and creating a directory called 'dtbs' and copying the file named am335x-boneblack.dtb into that directory.

More detail can be found here: http://www.element14.com/community/message/136214/l/re-bbb-s2-user-boot-button-not-working-on-element14-board

I learned a lot about this process here: https://www.marshut.net/irqnmm/changing-bbb-boot-default-from-emmc-to-usd.html

Kanoa (talk)

Interesting, I just got the Element 14 Rev C board and didn't see this problem. I did have to use the barrel jack though, and had the other issues I mentioned.

Cwshep (talk)

I think in this case you are using the S2 button to boot completely off the SD card and thereby getting a consistent U-Boot image. I'm just sticking the card in an powering up the board, which relies on the U-Boot image loaded on the eMMC. There's not a strong reason to do that except that booting without S2 is simpler and does not require using the barrel jack.

Kanoa (talk)

Ah, got it; thanks for the clarification -- I didn't realize you could bypass the S2 and barrel by doing it this way. This is handy :)

Cwshep (talk)

Hello, and thank you for this awesome tool!

I've successfully captured several .img files, which worked very well, and I've made the edits to autorun.sh to place these images back onto the emmc of a beaglebone.

The process of copying the image back to the emmc seems to go well, the light pattern matches what I see when copying an image from EMMC to SD: LED USR0 blinks for about 5 minutes, and then stops. I power off, and boot the system

Things seemed to work ok at first, most of my changes are intact....however, some things are not. A few files (/etc/hostname, /etc/hosts, and so on) are missing. I noted on further investigation that the filesystem is mounted read only, so there seems to be something wrong with the volume on the EMMC

Any idea what would cause this? Maybe just an improper shutdown before I captured the image?

Andris (talk)

I noticed that my images were only 2GB (see above comment). Can you verify you captured full images? Also, you can try dd'ing the captured image over to another sd card and mounting the partitions in linux to take a look at what you actually captured.

Cwshep (talk)

I'm working with BeagleBone Black Rev B6 (Debian) for work.

I would like to make an image of the emmc so I can duplicate the entire project with ease.

I've read multiple pages online describing the process of formatting an SD card, putting it into the BBB whilst powered off, and holding S2 when the board is powered on.

When I do this, the USER LED's do not turn on at all.

I've read this can be caused by not having enough power to the board.

I have tried a number of things to see what the issue:

* I've tested multiple boards (All BBB Rev B6)
* 2 different USB Cables
* 3 different USB ports
* 2 different 5v 1.2a power supplies
* Formatted my 16G SD Card (Came with the BBB) to FAT32 Partition, marked as active
* Copied over the files from the download as instructed
* Different combinations of holding the S2 button upon power on, pressing the reset button, etc etc

I believe that I can make an image of the OS and all the files on the BBB with the dd command, so that is what I will resort to. I will be preparing some 50+ of these BBB's in the coming month, and I would like a very easy and streamlined way of doing all this.

Thanks for the help

Cjohnweb (talk)

Further information:

* I am able to mount and read the SD card from within the OS on the BBB.

Question:

* When I am told that the SD card needs to be FAT formatted, is FAT32 sufficient for this? Or should I be using something like FAT16?

Cjohnweb (talk)

@Cjohnweb -- FAT32 worked for me (formatted from a Windows 7 virtual machine).

Initially, I had many failed attempts when I tried to extract the eMMC image. I tried different types of FAT file systems, using different OS's to perform the format, marking the card as 'active' or 'bootable', copying the files to the card in a specific order (so the MLO and u-boot.img files were first in the file allocation table), all to no avail. Eventually, I discovered you have to hold the S2 button while power is applied, and then release the button a few seconds later. Holding the S2 button and pressing RESET did NOT work for me. Holding the S2 button for too long also does not work (the board just turns off).

It all seems painfully simple in hindsight, but when I first read this Wiki article it didn't say anything about the S2 button, and nothing I tried worked. Even when I was holding the S2 button, I was just pressing RESET, which also doesn't work.

Hopefully this helps!

PausingReality (talk)