Boot custom kernel on PineBook Pro

[z4v4l]

if you are trying to run your own OS the FIRST TIME, maybe instead of that extlinux stuff, you just go a more controllable way - interrupt uboot by pressing a key, and type manually that stuff needed to run your OS:

Code:

load mmc n0:m0 <addr0> <pathtodtb>
fdt addr <addr0>
fdt resize
load mmc n1:m1 <addr1> <pathtokernel>
booti <addr1> - <addr0>

nX:mX correspond, of course, to the uboot numbers of storage devices, where appropriate files reside. if for example dtb is on eMMC and your OS is on SD, then X0 != X1.
and of course, as wdt said - the UART on rk3399 is running at 1500000 baud/sec