GnuBee PC-2 gets stuck in a bootloop

[Kirill Pimenov]

A couple of days ago I've finally got around to set up my PC-2, and managed to flash the latest stable OpenWRT (openwrt-21.02.2-ramips-mt7621-gnubee_gb-pc2) by downloading the official build, renaming it into GNUBEE.BIN on a FAT USB drive, and sticking it into the GnuBee. (Which, apparently, results into that firmware being flashed into the embedded flash on boot.)

I've played around with the system a bit (tried to set up my 4×12Tb WD drives into RAID6 with mdadm, but had to shut it down to google that 32-bit Linux kernels won't support filesystems with more than 16Tb on board, any in my setup I tried to format a single huge partition).

After I tried to reboot to resolve that issue, my PC2 stuck in a bootloop by the sound of it (I can constantly hear drives trying to spin up).

I've ordered a UART-to-USB with, and decided to wait for it for debug.

Today my UART finally arrived, and (after meddling a bit with port speeds, hardware flow control of minicom and proper connection of the TX/RX pins) — I still get a rather jibberish output (both via screen and via minicom):

U-Boot 1.1.3 (Aug 7 2017 - 16:23:41)

Boar

U-Boot 1.1.3 (Aug 7 2017 - 16:23:41)

Board: MediaTek APSoC DRAM: 512 MB

Config XHCI 40M PLL
MediaTek SPI flash driver, SPI clock: 45MHz
spi device id: 1 2 19 4d
find flash: S25FL256S
*** Warning - bad CRC, using default environment

==

U-Boot 1.1.3 (Aug 7 2017 - 16:23:41)

Board: MediaTek APSoC DRAM: 512 MB
======
icache: sets:256, ways:4, linesz:32, total:32768
dcache: sets:256, ways:4, linesz:32, total:32768

#### The CPU fset LAN/WAN WLLLL
(Re)start USB...
USB0: mtk-xhci: init hccr be1c0000 and hcor be1c0020 hc_length 32
Register 300010f NbrPorts 3
Starting the controller
USB XHCI 0.9
Config XHCI 40M PLL
MediaTek SPI flash driver, SPI clock: 45MHz
spi device id: 1 2 19 4d
find flash: S25FL256S
*** Warni:41
============================================
icache: sets:256, ways:4, linesz:32, total:32768
dcache: sets:256, ways:4,and hcor be1c0020 hc_length 32
Register 300010f NbrPorts 3
Starting the controller
USB XHCI 0.96
scanning bus 0 for devicesUSB0:

U-Boot 1.1.3 (Aug 7 2017 - 16:23:41)

1. What's up with the garbled output here? Is this something I should be fixing in my minicom setup or something? I'm not super-familiar with the tools here, to be honest.
   
2. Did I end up breakingUBoot on my device? If so — how do I fix it?
3. Is there a way to diagnose what lead to this breakage? What should I change to avoid such issues in the future?
   
4. Most of the conversations here are discussing either libreCMC or Debian for use on GnuBee. Am I making a mistake by picking OpenWRT? It seemed to be working just fine (both web UI and SSH) just yesterday...
   

[Jernej Jakob]

I'd suspect the power supply first. It may not be able to supply enough
current to power the drives.

Other than that, a hardware problem with the board is likely. Easy
things to check are the power input connector and power switch (you
could try flipping it on and off a lot if it happens to be a dirty
contact), or physical damage to the components (use a magnifier and
look for damaged or missing components).

I don't think flashing firmware would mess up uboot since it lives in a
separate partition on the flash which doesn't get touched.

> 1. What's up with the garbled output here? Is this something I should be

> fixing in my minicom setup or something? I'm not super-familiar with the
> tools here, to be honest.

> 2. Did I end up breakingUBoot on my device? If so — how do I fix it?
> 3. Is there a way to diagnose what lead to this breakage? What should I

> change to avoid such issues in the future?

> 4. Most of the conversations here are discussing either libreCMC or