Issue booting from SD om BBB while no problem on BBG, KERNEL 4.1.21-bone-rt-r20

Hello all,

I am struggling with booting the BBB REVC from 4GB class 10 uSD flashed with the image 4.1.21-bone-rt-r20 and u-boot image from branch v2016.07-rc2( I have followed all the steps from R.Nelson eewiki). when I press the S2 button and plug the 5V barrel supply I can see on my serial console CCCCCC while I was expecting at start to see all the 4 LEDS lighing on.
I used the same uSD card and try it on the BBG, the board boots without even pressing the S2 button.

Its there sometime I need to setup in the u-boot in order to correctly boot off uSD? I am wondering why I have no problem with the BBG? As I know they use the same ARM Core?

Thanks in advance for your answer.


Below the boot message on BBG without even pressing S2

[ 0.000000] Booting Linux on physical CPU 0x0
[ 0.000000] Initializing cgroup subsys cpuset
[ 0.000000] Initializing cgroup subsys cpu
[ 0.000000] Initializing cgroup subsys cpuacct
[ 0.000000] Linux version 4.1.21-bone-rt-r20 (beninio@mppdev) (gcc version 4.9.4 20151028 (prerelease) (Linaro GCC 4.9-2016.02) ) #3 Wed May 25 13:55:22 CEST 2016
[ 0.000000] CPU: ARMv7 Processor [413fc082] revision 2 (ARMv7), cr=50c5387d
[ 0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache
[ 0.000000] Machine model: TI AM335x BeagleBone Green
[ 0.000000] cma: Reserved 24 MiB at 0x9e800000
[ 0.000000] Memory policy: Data cache writeback
[ 0.000000] On node 0 totalpages: 131072
[ 0.000000] free_area_init_node: node 0, pgdat c0ab0d7c, node_mem_map de36d000
[ 0.000000] Normal zone: 1152 pages used for memmap
[ 0.000000] Normal zone: 0 pages reserved
[ 0.000000] Normal zone: 131072 pages, LIFO batch:31
[ 0.000000] CPU: All CPU(s) started in SVC mode.


Here the boot message from BBB REV C using the same uSD card pressing S2 and plug in the 5V barrel


Try holding and pressing the boot button while booting from sdcard. Let’s see if the new bootloder thinks the old one is too old.

Passed that, the only other thing I can think of offhand. Is double check to make sure you do not have the board file hard coded.

bonegreen == beaglebone green

boneblack == beaglebone black

lots to choose from though . . .

Hello William,

When keep holding boot button the boardd doesn’t boot indeed,

Hello William,

The board file use for this kernel are:

I still do not understand how I cannot boot properly off the uSD card on the BBB?

I have used a 4GB uSD Class 10, and use the following command to format it prior sending the kernel file, rootfs, modules… I have first sent the MLO and u-boot-dtb.img

sudo mkfs.ext4 -L rootfs ${DISK}1, one of the steo from Robert Nelson eewiki to format a uSD card.

It is a bit enoying that I can’t even clone another card to deploy on other BBB card.

Can you advise how to solve this? I still do not understand why on BBG I can boot without pressing the S2 button?

Here the boot message from BBB REV C using the same uSD card pressing S2 and plug in the 5V barrel


Ok, I did not see this yesterday, the C’s we blank on my end. Anyway, “CCCCCCCC. . .” means that the board can not find a suitable bootloader. Which in this case I’m not sure if this is firstage ( MLO ) or second stage ( uboot ).

But this is odd since the Beaglebone green is exactly the same board as the Beaglebone black, with just a few differences. I have not followed Roberts build from scratch guide in a year or more so I’ve not experienced this personally. However I can say that the latest Jessie testing image boots both as I very recently did just that. Booted both off the same sdcard.


I had the same issue on BBB, solution is in this link
You can give a try if you still facing this issue.