[meta-ti] Getting Started with meta-ti "rocko" and beaglebone black (BBB)

[William Mills]

Leo,

On 08/22/2018 02:18 PM, Leo Meza wrote:
> I'm learning yocto and was able to easily boot my BBB with a
> core-image-minimal system using the meta-yocto-bsp layer. However, when
> I removed that layer and tried with meta-ti, I just see this on the
> Putty serial console, it repeats over an over:
> 
> U-Boot SPL 2018.01-g6d540394a4 (Aug 22 2018 - 16:33:01)
> Trying to boot from MMC1
> *** Warning - bad CRC, using default environment
> 

I was able to duplicate this result when using meta-ti to build the
"beaglebone" machine.

TI builds and test the am335x-evm machine for all am335x based boards
inlcuding beaglebone.  If you switch to this machine you should have
better luck.

Note that as Denys said elsewhere TI images and default u-boot variable
settings assume that the kernel is in the root partition not the boot
partition.  The _path_ in the root partition should be /boot/zImage

The only thing you need in the boot partition is MLO and the u-boot.img.
If you want to override the u-boot settings you can have a uEnv.txt file
there.  Also if you save the environment from within u-boot it will end
up as a file in the boot partition named uboot.env

I notice that the am335x-evm machine does not create a .wic image so you
will have to assemble the parts from the deploy dir.
Put MLO and u-boot.img in the boot partition
untar the rootfs tar ball to the root partition
Put zImage and the short form *.dtbs in root partitions' /boot dir
untar the modules tar ball in the root partition.


> I'm copying MLO, zImage, u-boot.img, and am335x-boneblack.dtb to the
> BOOT (1st) partition of my uSD card. Then extracting
> core-image-minimal-beaglebone.tar.xz -C to the ROOT (2nd) partition of
> my uSD card. This works fine when using meta-yocto-bsp, but not with
> meta-ti. So, if anyone can help me understand what the different steps
> are between using the two different layers, I'd greatly appreciate it.
> Spent several days trying to figure this out so far.
> 
> Thanks in advance,
> Leo
> 
> 

Denys,

The beaglebone machine creates a much smaller MLO (~75K vs 109K) and
u-boot.img.
When you boot the image the SPL just spits out the message above over
and over.  It never gets to u-boot.

To reproduce I started with a clean clone of poky
added a clean clone of meta-ti
checked out rocko for both
. oe-*
edit conf/bblayers to take out yocto-bsp (for safty sake)
added meta-ti
built core-image-minimal for beaglebone machine.

Bill