Version Information:
OS: Linux laptop.julias.zone 6.1.0-6-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.15-1 (2023-03-05) x86_64 GNU/Linux
U-Boot: v2023.01

Toolchain Information:
arm-linux-gnueabihf-: from debian bookworm repos

Flashing to MMC:
dd if=u-boot-sunxi-with-spl.bin of=${card} bs=1024 seek=8