flashing eMMC

I downloaded the eMMC flasher image (images_BBB-eMMC-flasher-debian-7.4-2014-04-23-2gb.img.xz), put on it on a micro SD card (using dd), and tried the “hold the boot button when powering on”. Firstly I’m pretty concerned at this point that there is no easy way to know if it is really booting off the micro SD card or the eMMC. I had to eventually hook up ethernet and ssh in to figure out it was indeed booting off the debian linux on the micro SD card.

The very vague instructions say that flashing is done when there is no LED activity, and they become solid. Very vague indeed. I have no idea why it is not getting flashed. I am doing the boot up sequence properly, it is indeed booting up off the micro SD, but all the lights are flashing randomly until about 30 seconds later when they all blink at the same time, and remain that way indefinitely. The vague instructions say 45 mins, not 30 seconds, and the lights should be all on but solid, not flashing.

Should I be able to ssh into the device when it is flashing? If not then it is clearly not even trying to flash.

If there was some documentation on how to check if the flashing is actually happening or perhaps some way to execute it.


If all of the LED’s are flashing together then I believe there was an error while flashing the eMMC. Check the md5 on your eMMC flasher download to make sure there was no corruption. Then try re-flashing the SD with the eMMC flasher image and re-flash the eMMC.

If you’ve got a display hooked up, the debian flasher has a custom desktop background that says you’ve booted the MMC flasher in pretty large text.

Unfortunately I have no display. I do have a lapdock with mini hdmi, but when I boot off USB for power, the default installed image would disable hdmi output. According to blog posts I found at that time, it was doing what it was supposed to, as the system would go into USB host mode and assume you won’t be needing the display. Since none of the procedure documents mentioned there would be any screen output during the process, I would assume there would be no output. If there was even a comment such as “you can verify the flashing is actually occurring by viewing on display …”. Thanks for the tip! It would have prevented me from bricking it :slight_smile:

I bricked the eMMC :). I discovered this by hooking up to the network, and SSHing in. It was clearly showing it was running Debian. So I rebooted without holding the boot button, it would also load into Debian. I thought perhaps it did upgrade the eMMC (because I did leave it for some time – 60 mins plus), and booting up without pressing the boot button would result in booting into Debian. But in reality it was booting always from micro SD, because a) when I ejected the micro SD card and powered on, it would not boot at all (only power LED would be lit), and b) I noticed the / and /boot was mounting off the micro SD card rather than the eMMC. I shortly concluded that the flashing went bad, as after mounting the two eMMC partitions, I realized they were empty (with the latter being unformatted). So it looks like during the initial power on to flash, it didn’t flash properly (aborted, etc), and it seems you only have 1 go at it, as subsequent boots of micro SD would simply boot up the system and not flash the system.

Anyways… I couldn’t find any way of flashing it from command line (no tools exist that I could find, etc). What I ended up doing was formatting the unformatted parition with EXT4, and then rsync to the eMMC the /boot and / off the micro SD card. Powered down, ejected the micro SD card, and booted up successfully into Debian from eMMC.

I guess I’ll blog about my issue so that its available online for others who run into the same problem.

I checked the MD5 and it checked out ok (I had used the bittorrent link to download). I 'dd’ed the micro SD card, and like the first time, would do a sync to ensure it completely imaged. Like I mentioned, I know it was booting off the card but simply not flashing the eMMC. Like my subsequent post pointed out, it did at least try at one point, as it corrupted the two partitions. The issue is, subsequent reboots off the micro SD card would not invoke the eMMC flashing, and there is no instructions anywhere on the procedure to “manually force” invoke the process. I ended up resolving it my manually rsyncing the filesystems over to eMMC.