@StuMcBill
So, I've updated the bootloader to "NVME/USB Boot" (got the green screen and rapidly flashing green light), removed the SD card, placed a USB stick (flashed with Raspbian Lite) into one of the USB3 slots, and it won't boot.
I get the message below:
"Raspberry Pi 5 - 4GB
bootloader: 6fe0b091 2024/06/05
update-ts: 1718268387
board: c04170 ce7cb976 d8:3a:dd:a6:ef:65
boot: mode USB-MSD 4 order f14 retry 0/128 restart 1/-1
SD: card not detected
part: 0 mbr [0x00:00000000 0x00:00000000 0x00:00000000 0x00:00 power: supply: RPi USB-PD 5000 mA CC1 PMIC: reset normal 0x0 us net: down ip: 0.0.0.0 sn: 0.0.0.0 gw: 0.0.0.0
tftp: 0.0.0.0 00:00:00:00:00:00
display: DISPO: HDMI HPD=1 EDID=ok #2 DISP1: HPD=0 EDID=none #0
Boot mode: USB-MSD (04) order f1
USB2[1] 000206e1 connected
USB2[1] 0020003 connected enabled
USB2 root HUB port 1 init
USB2[1] 000206e1 connected
USB2[1] 00200e03 connected
enabled
USB2 root HUB port 1 init
USB MSD stopped. Timeout: 25
Boot mode: SD (01) order f
seconds
Failed to open device: 'scard'
Failed to
(cmd 371a0010 status 1fff0001)
Boot mode: RESTART (0f) order 0
open device: 'scard (cmd 371a0010 status 1fff0001)
Boot mode: USB-MSD (04) order f1
USB2\1) 000206e1 connected
USB2(1) 00200e03 connected enabled
USB2 root HUB port 1 init"
Any ideas?