I cannot flash BBB eMMC

Question

Hi all,

I am wroting down here these lines beacause I am quite confused, and maybe I am doing something wrong and I still don't know it.

I have a BBB revision A6. As far as I though, BBB boots from internal eMMC, and can not boot from SD, but

I doanloaded and Android image from here:

Beagleboard:Android - eLinux.org

The first thing it seems extrange for me is that eMMC is 2-GB while Android image is almost 4GB

I have used WIN32 disk imager to write the image in the SD card (I tried on winXP and win8), but when I try to flash the BBB I have no succes, I think I am following all the steps, unplug everything, plug SD card, hold down boot button (I have checked I am holding the write button) and power on while boot button is pressed, but nothing happens, 4 user LEDs are off. I have tried many times (about 20 times), I have changed the power supply, firstly that could be the problem, now I am using 5V 2.1A power supply, over the power connector.

But, what is even more extrange, is that if I power on the BBB with the SD card (with build-in Android image), and without presing any button, the BBB boots from SD card and starts Android, and If I power down, remove SD card and power on again, Angstrom distribution is still on BBB.

Has anyone seen this behave before?

Is it not posible flash this Android image because it is larger than eMMC?

So, if BBB can`t boot from SD, what I see when I power on the BBB with the SD card, is a wrong booting?

I am very confused and I really appreciate your help

Regards,

Miguel

Former Member · Accepted Answer

Ran Talbott wrote: 
 Interestingly, I accidentally discovered that I don't need to push the "user" switch during power-up to boot from SD. I believe this is because the SD cards have a uEnv.txt file in the small FAT partition that tells the on-board bootloader to use the SD partitions, instead of the MMC. 
 Actually you do need to push the button to boot from SD. What you're observing is the BBB booting u-boot from eMMC, that version of u-boot seeing the files on SD and giving those priority which is then able to re-direct part of the process to SD. If you delete either of the files MLO or u-boot.img from the first partition on the eMMC then it will not boot from SD unless you hold the button during power on. This two step process is fine as long as the u-Boot in eMMC and SD card are the same and the kernel on both eMMC and SD are the same, if they're different it can lead to all sorts of problems like booting the kernel from eMMC and using the filesystem from SD. This can mean you boot an Angstrom linux kernel from eMMC and then try to run Android from SD with predictable results.

rantalbott · Answer

My A6 just came in yesterday, but I'm assuming that it'll be able to boot from SD just like my A5s do.

Interestingly, I accidentally discovered that I don't need to push the "user" switch during power-up to boot from SD. I believe this is because the SD cards have a uEnv.txt file in the small FAT partition that tells the on-board bootloader to use the SD partitions, instead of the MMC.

You'll definitely have to put that Android image on an SD card, and run from there, because you're right:it can't be installed in the MMC because it's too big. If you try to install in the onboard, some directories will point tononexistent locations, and you may not even be able to boot

Ran

Former Member · Answer

The Android image from the site you reference is a stand-alone Android image for use booting from the SD card only .. it does not, and will not program the on-board eMMC as you desire. For that you will need to search for another "eMMC flasher" image with Android, not Angstrom Linux.

I cannot flash BBB eMMC

Top Replies