Porting U-Boot to a QCA9531 board?

[Wambui Karuga]

Hi

I'm trying to port the latest version of U-Boot (master branch) to a QCA9531
board, based on the QCA ap147 reference design which itself is OS image
compatible with the ap143 target of mainline U-Boot. The board comes with the
closed-source BREED bootloader from the manufacturer but it also fully works
with the open source U-Boot-mod by Pepe2k.

The board comes with a Chaos Calmer ar71xx mach based OpenWRT image which we
have upgraded to a fully working ath79 dts based image running the 5.4 Linux
kernel.

For U-Boot, initially we have modified the existing ap143 target and found the
following results which are consistent across U-Boot releases 2016-07, 2019-10,
2020-04 and latest master:
- Ethernet support is not working within U-Boot. Detection of the ethernet
  device fails with:  "Net: No ethernet found". The troubleshooting tip found
  here https://www.denx.de/wiki/view/DULG/NetNoEthernetFound doesn't resolve the
  problem
- With OpenWrt 18.06 (Kernel 4.4 - ar71xx mach target) and 19.07 (kernel 4.14 -
  ath79 dts target) the boot process doesn't complete and stalls at [link]. With
  OpenWrt Master (5.4) the boot process completes but the system displays the
  following issues: -- Within OpenWrt the watchdog timer (usually on GPIO 2)
  does not respond to writes on sysfs and therefore the device reboots every 4
  minutes -- The second USB hub on the board is not detected by OpenWrt during
  boot and therefore some devices do not come up on the operating system such as
  the modem.

My working config file is here[1], my device tree is here[2], the board file
here[3]  and my defconfig can be found here[4].

Am I running into an obvious oversight? What are the next steps I need to take
to get my port working?

Thanks,
wambui karuga
[1] https://github.com/wambu-i/u-boot/blob/getbox/include/configs/get-box.h
[2] https://github.com/wambu-i/u-boot/blob/getbox/arch/mips/dts/jangala,get-box.dts
[3] https://github.com/wambu-i/u-boot/blob/getbox/board/jangala/get-box/get-box.c
[4] https://github.com/wambu-i/u-boot/blob/getbox/configs/get-box_defconfig