Sorry, I have never used android on H3ULCB + KF.
But, I tested Yocto v3.21.0 on H3ULCB(ES2.0 4GB) + KF(M04) again.
And I confirmed that it works.
How about using yocto bootloader ?
if yocto can be booted, android bootloder may not be good for yocto...
Thanks for your help Y.H. With the Yocto-Firmware it boots as expected.
How I need to get the Android part working again, but boota is not supported in the Yocto's u-boot. But that's a different story now.
I prepared android 9 for H3ULCB(ES2.0 4GB) + KF(M4), and tested for booting yocto.
In my environment, yocto was booted with android's IPL and U-boot.
If you use old version of android, how about updating it ?
Thank you, this is very valuable feedback! I also used Android 9 with the same hardware as you have but for me it didn't work.
Would you mind posting the output of the full boot process including the u-boot environment varibles?
Here is my bootlog:
IPL is Rev.2.0.4 in my environment, but Rev.2.0.3 is used in your environment.
So, please update Android and IPL, then try to boot yocto v3.21.0 again.
Thank you very much for the boot-log of your system. I tried your suggestions with the new IPL and I'm now on the same version as you are.
Comparing the two logs (https://elinux.org/File:H3ulcb_yocto_with_android_ipl_kh.txt) they look very similar - except some memory addresses during IPL which I don't understand why they are different. Even the Kernel Size is identical - but the device tree is not.
$ md5sum *
$ ls -l
-rw-r--r-- 1 root root 16497152 Apr 7 09:53 Image
-rw-r--r-- 1 root root 92809 Apr 7 09:53 Image-r8a7795-h3ulcb-kf.dtb
I did a recompile of my yocto to rule out any problems there. Also there are no local modifications done.
If you still have the files, would you mind uploading your Image.dtb (if it really differs) and also your srec files? This way I would be able to rule out some hardware issue on my side.