U-Boot loader and related files for the StarFive VisionFive v2 (JH7110).

The SD card must be formatted with a GPT partition scheme, and expects two
specific GUID partition types for the SPL and FIT image.

Assuming an SD card device in /dev/da2, execute:
# gpart create -s gpt da2
# gpart add -l spl -t \!2E54B353-1271-4842-806F-E436D6AF6985 -b 2m -s 2m da2
# gpart add -l uboot -t \!BC13C2FF-59E6-4262-A352-B275FD6F7172 -b 4m -s 4m da2

Now, copy the u-boot files to the SD card with dd(1).
dd if=/usr/local/share/u-boot/u-boot-starfive-visionfive2/u-boot-spl.bin.normal.out \
    of=/dev/da2p1 conv=sync
dd if=/usr/local/share/u-boot/u-boot-starfive-visionfive2/u-boot.itb \
    of=/dev/da2p2 conv=sync
