Follow-up to this note

Meanwhile Dragans changes to the dtb file helped my testing setup to boot without eMMC. So I could test booting manually from scsi devices like on my production system.

Looking for some simple instructions on how-to do this failed and I put together the following information.

u-boot on #RockPro64 uses variables written to flash. The important ones for choosing a device/kernel to boot:

# this u-boot will look for scsi devices only
boot_targets=scsi
# it will scan the devices for 
bootcmd=bootflow scan

Since I have a boot.scr in my /boot the bootmeth seems to be script. There's also the source of that file boot.cmd available and from there I extracted the commands to run on the u-boot console to start any kernel/initrd/dtb I could find on disk:

# initialize pci bus
pci enum
# show devices on pci
pci
# reset bus and scan for scsi devices
scsi reset
# get partition table
scsi part
# find boot files
ls scsi 0:1 /boot
# load armbian defaults
load scsi 0:1 0x800800 /boot/armbianEnv.txt
# replace the xyz on the following line with the
# filesize output by 'load' above
env import -t 0x800800 xyz
# write uuid of partition to variable partuuid
part uuid scsi 0:1 partuuid
# arguments passed to the kernel on boot
setenv bootargs "root=${rootdev} rootwait rootfstype=${rootfstype} ${consoleargs} consoleblank=0 loglevel=${verbosity} ubootpart=${partuuid} usb-storage.quirks=${usbstoragequirks} ${extraargs} ${extraboardargs}"
# look for available images, initrds and dtbs
ls scsi 0:1 /boot
# get the dtb directory, **uInitrd** and the vmlinuz
# from the output to use with the following 'load' commands
load scsi 0:1 0x02080000 /boot/
load scsi 0:1 0x06000000 /boot/
load scsi 0:1 0x01f00000 /boot//rockchip/rk3399-rockpro64.dtb
booti 0x02080000 0x06000000 0x01f00000

At this point I only needed to wait for the Pine64 sata ctrl to arrive to test the current kernel with the same ctrl used in my production system.

So I went back to the fork in the tunnels and took the other way down the #RabbitHole…