Reflashing a TechNexion PICO-PI-IMX7 (Android Things)

flash-imx7d.md

Preword

This is based in liquidx Board docs pdf

Mfgtool

Use libuuu_1.4.43-32-geb273fb for legacy chips, obtained from pico-imx7_pico-pi_yocto-3.0-qt5_qca9377_lcd-800x480_20210429.zip. First, unzip the file. Then use mfgtool attached imx-mfg-uuu-tool-20210421.zip

Note: I dod not get any newer tool (1.5.x) working.

Tool preparation

We will npack tool into imx-mfg-uuu-tool and this will be our working directory.

1. unzup imx-mfg-uuu-tool-20210421.zip
2. cd imx-mfg-uuu-tool
3. ln -sf ln -sf imx7/pico-imx7/imx7-SPL _SPL
4. ln -sf imx7/pico-imx7/imx7-u-boot.img _UBOOT

• Note: Do not link the compressed image to _root.sdcard, as sometimes it does not get picked by flasher.

Setting up the board

Set jumpers as in Figure 19 - PICO-PI-IMX7 Boot Control Pins of doc into Serial Boot Loader mode.

• Note: eMMC boot setup is depicted on

Connect board to the USB-C of the computer. It should be visible as an usb device:

majduk@majduk:~/Documents/imx-mfg-uuu-tool$ lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
...
Bus 003 Device 119: ID 15a2:0076 Freescale Semiconductor, Inc. i.MX 7Solo/7Dual SystemOnChip in RecoveryMode

Check if uuu detects the board:

majduk@majduk:~/Documents/imx-mfg-uuu-tool$ sudo ./uuu/linux64/uuu -lsusb
uuu (Universal Update Utility) for nxp imx chips -- libuuu_1.4.43-32-geb273fb

Connected Known USB Devices
	Path	 Chip	 Pro	 Vid	 Pid	 BcdVersion
	==================================================
	3:1	 MX7D	 SDP:	 0x15A2	0x0076	 0x0001

Flashing

0. cd imx-mfg-uuu-tool
1. Obtain image from pico-imx7-emmc/archived/

wget https://download.technexion.com/demo_software/PICO/IMX7/pico-imx7-emmc/archived/pico-imx7_pico-pi_yocto-3.0-qt5_qca9377_lcd-800x480_20210429.zip

2. unzip pico-imx7_pico-pi_yocto-3.0-qt5_qca9377_lcd-800x480_20210429.zip
3. Flash:

sudo ./uuu/linux64/uuu -b emmc_imx7_img _SPL _UBOOT pico-imx7_pico-pi_yocto-3.0-qt5_qca9377_lcd-800x480_20210305/fsl-image-qt5-validation-imx-pico-imx7-20210429040519.rootfs.wic.bz2

Tested images

Working images:

• pico-imx7_pico-pi_ubuntu-22.04_qca9377_lcd-800x480_20230607. Note: decompress the bz2 first.
• pico-imx7_pico-pi_yocto-4.2-qt6_qca9377_lcd-800x480_20240820. This one does not have any tools in it.
• pico-imx7_pico-pi_yocto-3.0-qt5_qca9377_lcd-800x480_20210429.zip
• pico-imx7d_pi_ubuntu-20.04-xfce_QCA9377_5-lcd-800x480_20211012.zip, flashes correctly, documentation

Non working:

• pico-imx7_pico-pi_ubuntu-22.04_qca9377_lcd-800x480_20221219.zip. Note: decompress the bz2 first. Gets flashed without errors but does not boot.