The Nezha boot ROM can read the boot0 SPL from two different locations:

* starting at sector 16
* starting at sector 256

The location in sector 16 is incompatible with GPT partioning which by default
uses 34 sectors. In gdisk you would have to reduce the number of entries in the
partition table to ≤ 56 via the expert settings. It is preferable to write
boot0 starting at sector 256 instead:

sudo dd if=/usr/lib/u-boot/nezha/boot0_sdcard_sun20iw1p1.bin of=/dev/sdX \
        bs=8192 seek=16 conv=fsync,notrunc
