On 03/14/2018, the 3b+ was released to the world. Rasbian saw an update to support the new board, but the debian buster preview image has not been updated since early January 2018. As a result, it does not by default work with the new 3b+. Yet the question is: just how difficult would it be to get it working?
Many of these ARM SBCs utilize device tree blobs (dtb files) to describe the hardware layouts of a particular board.
These dtb files are found in the boot partition. For example, on the latest rasbian (on a pi3b):
root@pi3b:/boot# ls -l *.dtb -rwxr-xr-x 1 root root 22264 Apr 1 09:33 bcm2708-rpi-0-w.dtb -rwxr-xr-x 1 root root 22020 Apr 1 09:33 bcm2708-rpi-b-plus.dtb -rwxr-xr-x 1 root root 21761 Apr 1 09:33 bcm2708-rpi-b.dtb -rwxr-xr-x 1 root root 21474 Apr 1 09:33 bcm2708-rpi-cm.dtb -rwxr-xr-x 1 root root 23044 Apr 1 09:33 bcm2709-rpi-2-b.dtb -rwxr-xr-x 1 root root 24503 Apr 1 09:33 bcm2710-rpi-3-b-plus.dtb -rwxr-xr-x 1 root root 24240 Apr 1 09:33 bcm2710-rpi-3-b.dtb -rwxr-xr-x 1 root root 22952 Apr 1 09:33 bcm2710-rpi-cm3.dtb root@pi3b:/boot#
Notice the bcm2710-rpi-3-b-plus.dtb file… that's what we're interested in.
Specify the correct dtb file on the device_tree option:
node00:/mnt# cat config.txt # Switch the CPU from ARMv7 into ARMv8 (aarch64) mode arm_control=0x200 enable_uart=1 device_tree=bcm2710-rpi-3-b-plus.dtb kernel=vmlinuz-4.14.0-3-arm64 # For details on the initramfs directive, see # https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=10532 initramfs initrd.img-4.14.0-3-arm64 node00:/mnt#