I’m trying to flash Android into eMMC. I wrote an Angstrom image into an SD card. I booted BBB wtih that SD card. I create three partions on eMMC for Android via terminal in Angstrom. From this point, I’m not sure which files I must copy to eMMC’s boot and rootfs partitions. And I think I must modify some files because I used an image which runs on SD card (I think I must change mmcblk0 references to mmcblk1). Long story short:
- Which files I need to copy to eMMC’s which partitions?
- Which files should I modify for my image to run on eMMC? (mmcblk0 to mmcblk1 problem)
If you can help me, I’ll be grateful 
And sorry for my English
Hi Gerald. Thanks for the answer. But I’m not trying to boot Android from SD card. I’m trying to flash Android files into onboard eMMC. I want to boot Android without SD card.
Oh, I understand totally. But, the idea is to make sure the board is OK and functioning, so that is what I suggest going back to the factory image to make sure. Then work the Android issue. I don’t know of anyone that has flashed the eMMC with an Android image. everything i have seen so far is SD card booting only. But it should be possible.
Gerald
Hi Gerald,
Could you please tell us how this is possible as i also want to flash android or even ubuntu desktop on eMMC. b’coz i want to speed up the OS. I have ubuntu on sdCard but it is very slow.
The goal here is to make the sure hardware is good. Flash the factory image and make sure the board works.
Then flash whatever image you like over the factory image. If it does no work, then your image has issues.
Gerald
I’m not an expert but I think, If you want speed, you should use an SD cards like this:
http://www.samsung.com/uk/consumer/memory-cards-hdd-odd/memory-cards-accessories/micro-sd-plus-accessories/MB-MPAGA/EU?subsubtype=micro-sd-plus-accessories
or something which has min 30 mb/s read speed. I’m using the one in the link and my Beaglebone is working without a problem with TI’s Android image. Don’t waste your time trying to boot Beaglebone from eMMC. If you use a high speed SD card you’ll get better performance.
eMMC runs at 48MHZ.
uSD runs at 48MHz.
eMMC is 8bit.
uSD is 4bit.
Gerald
eMMC runs at 48MHZ.
uSD runs at 48MHz.
eMMC is 8bit.
uSD is 4bit.
Hi Gerald,
Based on the specs, you would think that eMMC would run faster, but it doesn’t. Run the following Linux command to test the speed of each device:
sudo hdparm –tT /dev/mmc0blk0p1
SDCard 21MB/s
eMMC 12MB/s
This doesn’t make sense, but perhaps there is something else going on.
Regards,
John
I agree.I suspect that the eMMC is actually set to 4bit in some of the kernels and there may be other issues going on as well…
Gerald
The device tree file for the BBB shows it in 8bit mode.
What I am thinking is that perhaps the low level block device driver in the kernel needs optimizing. That and it is not specific to the eMMC either. I have no proof here, I have just been noticing a trend with 21MB/s about the ceiling for storage speeds. Booting from USB also shows hdparm speeds max of 21MB/s( writes ) with reads at 10MB/s. The write / read speeds seems to be swapped when compared to an x86 Windows, or Linux system. So yeah, seems a bit fishy to me.
I got over 30MB/s read speed on freescale iMX6 with 8bit eMMC 4.4 spec @49.5M
And Joe Walsh has a Maserati that does 185 . . .
Does those platforms use the same exact drivers ?