H96 Max RK3528 - Cannot boot Armbian from TF/SD card

[Alexander Polko]

Hello,
I have H96 Max TV box with RK3528 chip (4GB RAM, 64GB eMMC, Android 13, build RZX.V01.20240924). Board: RK3528_DDR3_8X4_V12.
Problem: Box does not boot from TF card at all. No HDMI output, no DHCP lease, nothing.
What I have:

TF card slot on the box
1x USB 2.0 port, 1x USB 3.0 port
No serial/UART adapter (DEBUG header visible on PCB but not connected)
Android 13 still working on EMMC
ADB access with root

What I tried:

Built Armbian with BOARD=rk3528-tvbox BRANCH=legacy BUILD_MINIMAL=yes RELEASE=trixie
Extracted DTB from Android boot partition, added to image
Wrote image to TF card with dd
Verified RKNS header at sector 64 - correct
Tried replacing idbloader with one from our custom U-Boot build
Original U-Boot on EMMC appears to ignore TF card completely

Question: How to make original U-Boot boot from TF card? Or is there a way to install Armbian to EMMC safely while keeping ability to recover?
Device AIDA64 info:

Model: H96_Max_RK3528
Device: rk3528_box
Hardware: rk30board

Thank you!

[jock]

Hello, you can only boot from sdcard with that device if you follow the rockchip boot sequence, ie: you have to pack u-boot and trust.img using loaderimage tool from rockchip rkbin repository.

 

That tools decorates the uboot/trust.img binaries with some signature and checksum, then you have to put on specific positions on your sdcard and the miniloader, residing in the emmc, will boot from sdcard once it validates correctly the binaries you supplied.

 

You may take a look to my multitool github project for some reference. I have you same box and it boots on mine.

 

Unfortunately on this particular box, the manufacturer disabled the sdcard boot at SoC/hardware level: this means that the trick to erase the internal flash to boot from sdcard, which worked fine for older SoCs, does not always work with rk3528-based (and probably other rk35xx) boards