Cubieboard 1 (A10): "DRAM: Timeout initialising DRAM" with every mainline U-Boot, stock NAND boot0 works

Hi,

I have a Cubieboard 1 (A10, 1 GB, silkscreen "CubieBoard.org 2012-09-09"). It boots its stock Android from NAND without problems, but every U-Boot SPL I put on the SD card fails in a reset loop:

U-Boot SPL 2023.10 (Oct 29 2026 - 19:47:12 -0300) DRAM:Timeout initialising DRAM

resetting ...

What I tried (same result every time):

- Armbian 23.11.1 (bookworm, 6.1.63), Armbian 26.11 Debian 13 and Ubuntu 26.04 images (SD card verified, armbi_root ext4 present)

- Debian u-boot-sunxi 2023.01 and 2021.01 (Cubieboard target), written with dd seek=8 - U-Boot v2023.10 built myself from Cubieboard_defconfig, with DRAM_CLK 480, 408 and 360

-AXP209 voltages copied from the stock boot0 (DCDC2 1450, DCDC3 1300)

- Powered from a PC USB port (mini-USB OTG) instead of the original 5 V supply

Also tried Debian jessie U-Boot 2014.10+dfsg1-5 (2015): same Timeout initialising DRAM

Stock boot (no SD card) starts like this:

HELLO! BOOT0 is starting!

boot0 version : 3.0.0

dram size =1024

...

U-Boot 2011.09-rc1-00003-ge89ab14-dirty (Jan 03 2014 - 12:57:33) Allwinner Technology

PMU: AXP209 ... after set, dcdc2 =1450mv ... dcdc3_vol = 1300 ... ldo2_vol = 3000

...

dram_para_set start

dram_para_set end DRAM: 1 GiB

So the factory boot0 initialises the same RAM fine. Defaults in my build: DRAM_CLK=480, DRAM_ZQ=123, DRAM_ODT_EN not set, DRAM_EMR1=0, DRAM_TPR3=0.

Does anyone know whether some Cubieboard 1 revisions need different DRAM parameters (ZQ, ODT, EMR1, TPR3, DQS gating), or how to get the exact values from the stock firmware? Any hint is appreciated.

Thanks!

Edited Friday at 09:10 PM2 days by elnoelito213