Due to an incident during production, on some boards the partition of the flash containing the u-boot environment variables, has not been written properly with the u-boot default environment variables, and therefore it does not contain the necessary information to boot. This is causing the device to remain in u-boot.
Note that this does not impact device hardware quality in any way, and that the flash memory that contains the u-boot variables has been functionally tested.
To check if your device is affected all you need is a MicroUSB cable. Connect the cable to the UART port of your carrier open the serial port terminal of choice, power on the board and see if the following text is being displayed:
Model: Zynq Zed Development Board Board: Xilinx Zynq Silicon: v3.1 DRAM: ECC disabled 512 MiB MMC: sdhci@e0100000: 0 (SD) SF: Detected n25q256a with page size 256 Bytes, erase size 4 KiB, total 32 MiB In: serial@e0001000 Out: serial@e0001000 Err: serial@e0001000 Net: ZYNQ GEM: e000b000, phyaddr 0, interface rgmii-id eth0: ethernet@e000b000 Zynq>
Please perform the following steps to eliminate the issue:
From your serial port terminal run the following commands:
Zynq> env default -a Zynq> setenv ethaddr "<MAC_ADDR_FROM_STICKER>" Zynq> saveenv Zynq> reset
If you get an error after saveenv, then your flash partition had also been locked. To unlock it and then write the proper environment variables, please follow these steps:
Zynq> env default -a Zynq> run sdboot
The board will now boot in Linux. Once done, run the following commands:
root@analog:~# flash_unlock /dev/mtd1 root@analog:~# flash_erase /dev/mtd1 0 0 root@analog:~# rebootWhen hitting reboot, please pay attention to the prompt “Hit any key to stop autoboot: 3…2…1”. When that appears, please press any button to re-enter uboot. Then, all is left to do is to write the default environment variables and save:
Zynq> env default -a Zynq> setenv ethaddr "<MAC_ADDR_FROM_STICKER>" Zynq> saveenv Zynq> reset
The board will then reset, boot normally and be ready to use for your applications. If you have a different issue or these steps have not worked out for you, we offer support at Engineer Zone.