Wiren Board 7: Errata

	7.2.1	7.3
ERRWB70001
Legend	Not affected by the problem
	Affected, fixed by software update
	Affected

ERRWB70001: Controller won't boot after next reboot

Affected devices

Wiren Board 7 of all revisions with loader version 1.1.1 released before July 15, 2022

Description

A normally working controller does not turn on after the next power reset. The indication LED lights up yellow for about 20 seconds, then goes out for a few seconds, then the cycle repeats.

The debug console says:

U-Boot SPL 2021.10-wb1.1.1-g4c04347f3e (Feb 03 2022 - 14:48:16 +0000)
DRAM:

Normal boot hangs after DRAM line.

Sometimes the problem only appears if a microSD card is inserted into the controller.

Reasons and details

The bootloader incorrectly initializes the RAM by not waiting for the PLL to stabilize before accessing the DRAM chips.

Bypasses

If a microSD card is inserted, try removing and updating the bootloader as described above.

Fixed

Fixed in U-Boot version 2021.10-wb1.1.2.

The update has been ported to stable wb-2204 and testing.

To update, run three commands in turn:

apt update
apt install u-boot-wb7
u-boot-install-wb

It is recommended to update the bootloader on all controllers. The problem may show up on them later.

If the controller is no longer loading, then there are two ways to bring it back to life:

1. writing a special image to a blank microSD card;
2. connecting to a computer via the first USB-C and running the sunxi-fel utility.