I have U-boot 2020.10 installed and if I stop the start up process I can loag the images from the USB drive into memory and boot into the Debian install on my drive.
U-Boot 2020.10 (Jul 23 2026 - 00:40:47 +0000) NS v2 SoC: Kirkwood 88F6281_A1 I2C: ready DRAM: 256 MiB Loading Environment from SPIFlash... SF: Detected mx25l4005a with page size 256 Bytes, erase size 4 KiB...
U-Boot 2020.10 (Jul 23 2026 - 00:40:47 +0000) NS v2 SoC: Kirkwood 88F6281_A1 I2C: ready DRAM: 256 MiB Loading Environment from SPIFlash... SF: Detected mx25l4005a with page size 256 Bytes, erase size 4 KiB...