iMX6 OpenRex Basic Recovery

Description

The recovery procedure consists of following steps:

Loading bootloader binary over USB using Mfgtool feature
Flashing new bootloader over Ethernet using TFTP
Erasing bootloader environment
Resetting SBC
Creating a new SD card containing filesystem

Requirements:

Mfg_tool
Serial adapter with terminal application
TFTP server
DHCP server (optional)

This procedure is intended to be used to erase bootloader environment or to load the default environment.

Updating bootloader

Using Mfgtool

If the board is unable to boot (e.g. when bootloader was deleted or not transferred successfully), USB Booting option should be used to load the image file.

From TFTP server

Download the U-Boot image (on computer acting as TFTP server):

cd /srv/tftp/imx6/
wget http://downloads.voipac.com/files/iMX6_OpenRex_SBC/software/uboot/binaries/u-boot-imx6-openrexbasic-2.4.imx

Update the bootloader in U-Boot:

setenv ipaddr 192.168.0.150
setenv serverip 192.168.0.1

mw.b 0x10800000 0xFF 0x80000;if tftp 0x10800000 imx6/u-boot-imx6-openrexbasic-2.4.imx; then if sf probe 2:2; then sf erase 0x0 0x80000;sf write 0x10800000 0x400 0x7fc00; fi; fi
reset

From SD card

Creating SD card in Linux

Create VFAT partition:

sudo fdisk /dev/sdX

Unplug/plug SD card and format the partition afterwards:

sudo mkfs.vfat /dev/sdX1

Check if device was correctly mounted and copy bootloader into it:

cd /media/user/61B3-D9BF 
wget http://downloads.voipac.com/files/iMX6_OpenRex_SBC/software/uboot/binaries/u-boot-imx6-openrexbasic-2.4.imx

Update the bootloader in U-Boot:

mw.b 0x10800000 0xFF 0x80000;
if fatload mmc 0:1 0x10800000 u-boot-imx6-openrexbasic-2.4.imx; then if sf probe 2:2; then sf erase 0x0 0x80000;sf write 0x10800000 0x400 0x7fc00; fi; fi
reset

Erasing bootloader environment

OpenRex U-Boot > env default -f -a
## Resetting to default environment
OpenRex U-Boot > saveenv
Saving Environment to SPI Flash...
SF: Detected SST26VF032B with page size 256 Bytes, erase size 4 KiB, total 4 MiB
Erasing SPI flash...Writing to SPI flash...done

Creating bootable SD card

If a fresh SD card containing filesystem is needed, follow these steps to prepare the device.