Official Debian support!

[Nikolay_Po]

Have tried pineperson's recommendations about files for booting. No boot. Console output:

U-Boot TPL 2020.07+dfsg-1 (Jul 08 2020 - 23:29:02)
Channel 0: LPDDR4, 50MHz
BW=32 Col=10 Bk=8 CS0 Row=15 CS1 Row=15 CS=2 Die BW=16 Size=2048MB
Channel 1: LPDDR4, 50MHz
BW=32 Col=10 Bk=8 CS0 Row=15 CS1 Row=15 CS=2 Die BW=16 Size=2048MB
256B stride
256B stride
lpddr4_set_rate: change freq to 400000000 mhz 0, 1
lpddr4_set_rate: change freq to 800000000 mhz 1, 0
Trying to boot from BOOTROM
Returning to boot ROM...

U-Boot SPL 2020.07+dfsg-1 (Jul 08 2020 - 23:29:02 +0000)
Trying to boot from MMC1
mmc_load_image_raw_sector: mmc block read error
Trying to boot from SPI
Trying to boot from MMC1
mmc_load_image_raw_sector: mmc block read error
Trying to boot from MMC2
mmc_load_image_raw_sector: mmc block read error
SPL: failed to boot from all boot devices
### ERROR ### Please RESET the board ###

At the end of Debian installation I got a message: "You will need to boot manually with the /vmlinuz kernel on partition /dev/mmcblk01p1 and root=/dev/mmcblk0p2 passed as a kernel argument".
So I tried root=/dev/mmcblk0p2 first. The tried root=/dev/mmcblk0p3 - no luck. Then connected UART to console output to discover it completely broken.