This might be interesting. It seems like it tries SD but cannot find valid partitions...
U-Boot 2022.04-armbian (Feb 13 2023 - 01:06:32 +0000)
SoC: Rockchip rk3399
Reset cause: POR
Model: Firefly ROC-RK3399-PC-PLUS Board
DRAM: 3.9 GiB
PMIC: RK808
Core: 295 devices, 29 uclasses, devicetree: separate
MMC: mmc@fe310000: 2, mmc@fe320000: 1, mmc@fe330000: 0
Loading Environment from SPIFlash... SF: Detected w25q128 with page size 256 Bytes, erase size 4 KiB, total 16 MiB
*** Warning - bad CRC, using default environment
In: serial
Out: serial
Err: serial
Model: Firefly ROC-RK3399-PC-PLUS Board
Net: eth0: ethernet@fe300000
Hit any key to stop autoboot: 0
starting USB...
Bus usb@fe380000: USB EHCI 1.00
Bus usb@fe3c0000: USB EHCI 1.00
Bus usb@fe900000: Register 2000140 NbrPorts 2
Starting the controller
USB XHCI 1.10
scanning bus usb@fe380000 for devices... 1 USB Device(s) found
scanning bus usb@fe3c0000 for devices... 2 USB Device(s) found
scanning bus usb@fe900000 for devices... 1 USB Device(s) found
scanning usb for storage devices... 0 Storage Device(s) found
Device 0: unknown device
switch to partitions #0, OK
mmc1 is current device
** No partition table - mmc 1 **
Couldn't find partition mmc 1:1
switch to partitions #0, OK
mmc0(part 0) is current device
Scanning mmc 0:1...
Found /boot/extlinux/extlinux.conf
Retrieving file: /boot/extlinux/extlinux.conf
1: Armbian
Retrieving file: /boot/uInitrd