legacy bootloader does not load kernel 5.10.y, to solve this problem you need to load dtb and initrd into different addresses.
also added support for rock pi s to the mainstream loader.
MMC: dwmmc@ff480000: 1, dwmmc@ff490000: 01, State ON (0x0)
In: serial
Out: serial
Err: serial
Model: Radxa ROCK Pi S
rockchip_dnl_key_pressed read board id failed
Net: eth0: ethernet@ff4e0000
Hit any key to stop autoboot: 0
switch to partitions #0, OK
mmc1 is current device
Scanning mmc 1:1...
Found U-Boot script /boot/boot.scr
1650 bytes read in 3 ms (537.1 KiB/s)
## Executing script at 00500000
Boot script loaded from mmc 1
54 bytes read in 3 ms (17.6 KiB/s)
51492 bytes read in 7 ms (7 MiB/s)
28514816 bytes read in 1207 ms (22.5 MiB/s)
libfdt fdt_getprop(): FDT_ERR_NOTFOUND
8962432 bytes read in 383 ms (22.3 MiB/s)
Moving Image from 0x680000 to 0x800000, end=23d0000
## Loading init Ramdisk from Legacy Image at 04000000 ...
Image Name: uInitrd
Image Type: AArch64 Linux RAMDisk Image (gzip compressed)
Data Size: 8962368 Bytes = 8.5 MiB
Load Address: 00000000
Entry Point: 00000000
Verifying Checksum ... OK
## Flattened Device Tree blob at 02800000
Booting using the fdt blob at 0x2800000
Loading Ramdisk to 1d6a6000, end 1df32140 ... OK
Loading Device Tree to 000000001d631000, end 000000001d6a5fff ... OK
Starting kernel ...
[ 2.400141] rockchip-pinctrl pinctrl: pin gpio1-22 already requested by ff0c0000.serial; cannot claim for ff140000.spi
[ 2.412245] rockchip-pinctrl pinctrl: pin-54 (ff140000.spi) status -22
[ 2.419585] rockchip-pinctrl pinctrl: could not request pin 54 (gpio1-22) from group spi2-miso on device rockchip-pinctrl
[ 2.431971] rockchip-spi ff140000.spi: Error applying setting, reverse things back
[ 8.218869] rk_gmac-dwmac ff4e0000.ethernet: Can not read property: tx_delay.
[ 8.227340] rk_gmac-dwmac ff4e0000.ethernet: set tx_delay to 0x30
[ 8.234867] rk_gmac-dwmac ff4e0000.ethernet: Can not read property: rx_delay.
[ 8.243873] rk_gmac-dwmac ff4e0000.ethernet: set rx_delay to 0x10
=======================================================================
if you want to transfer the system to SD card to internal memory (eMMC or NAND),
follow setup
login: root
password: password
=======================================================================
slarm64 GNU/Linux (ttyS2)
Kernel 5.10.2 (aarch64)