Flashing SD Card with Linux Image using the USB Serial Downloader

Installing Images Using USB Serial Downloader Protocol (SDP)

The preferred method of installing Yocto images to SD card is this: Flashing SD Card with Linux Image from Linux Host. However sometimes, extracting the SD card from the kit is not possible (for example, when the kit is installed to a device and is not easily accessible). In this case, use the method below.

Perform the following step-wise procedure to install the Yocto images to SD card installed into i.MX 8M NAVQ Plus kit:

Power the kit off by disconnecting the USB Type C cable from the development host.
Set the target boot mode to the USB serial downloader mode by setting the boot switches as follows:
- SW2.1 - 1
- SW2.2 - 0
Power the kit on by connecting the USB Type C cable to the development host. Use the kit port labeled USB1.

Check that the new USB device has appeared on your development host:

[psl@i7 ~]$ lsusb | grep -i nxp 
Bus 001 Device 025: ID 1fc9:0146 NXP Semiconductors

On the host, go to the Yocto images directory:
```
[psl@i7 ~]$ cd ~/5-15-5-DESKTOP/builddir/tmp/deploy/images/imx8mpnavq 
[psl@i7 imx8mmnavq]$ ls -1
...
imx-boot-imx8mpnavq-sd.bin-flash_evk
imx-image-desktop-ros-imx8mpnavq.wic.zst
uuu
...
```
- The images above are:
- imx-boot-imx8mpnavq-sd.bin-flash_evk - U-Boot-ATF-OPTEE boot image;
- imx-image-desktop-ros-imx8mpnavq.wic.zst - Ubuntu root filesystem;
- uuu - pre-built image of the uuu utility (you could also use pre-built uuu image from https://github.com/NXPmicro/mfgtools/releases/latest, or build it from sources https://github.com/NXPmicro/mfgtools/tree/master);

Unpack the compressed image of the root filesystem:

[psl@i7 imx8mmnavq]$ zstd -d imx-image-desktop-ros-imx8mpnavq.wic.zst
...

Launch the uuu tool with appropriate script as a parameter for installing the bootable Linux image:

[psl@i7 imx8mmnavq]$ sudo ./uuu -v -b sd_all imx-boot-imx8mpnavq-sd.bin-flash_evk imx-image-desktop-ros-imx8mpnavq.wic
uuu (Universal Update Utility) for nxp imx chips -- libuuu_1.3.82-0-g9c56e46

Wait for Known USB Device Appear...

The uuu tool will proceed to install the Production Yocto image to the storage device (SD card) on the target board:

uuu (Universal Update Utility) for nxp imx chips -- libuuu_1.3.74-2-g302da91 

Success 1 Failure 0
...
1:3 7/ 7 [Done ] FB: Done

When uuu has finished, the bootable Linux image has been installed to the on-module storage. Given proper setting of the boot switches, next power-on will boot the target board from the SD storage device.

Verifying New Installation

Perform the following step-wise procedure to verify boot of the newly installed Linux images from the SD card plugged into the kit:

Power the kit off by disconnecting the USB Type C cable from the development host.
Select the appropriate boot mode (boot from SD) by setting the boot switches as follows:
- SW2.1 - 1
- SW2.2 - 1
Power the kit on by connecting the USB Type C cable to the development host.

Verify that the following Linux boot-up messages appear on the serial console:

NOTICE:  BL31: v2.4(release): 
NOTICE:  BL31: Built : 05:49:10, Mar  2 2022


U-Boot 2021.04-lf_v2021.04+g60519b47e7 (Jul 31 2022 - 08:56:04 +0000)

CPU:   i.MX8MP[8] rev1.1 1800 MHz (running at 1200 MHz)
CPU:   Commercial temperature grade (0C to 95C) at 44C
Reset cause: POR
Model: Voxelbotics NAVQPlus board
DRAM:  4 GiB
...
Starting kernel ...

[    0.000000] Booting Linux on physical CPU 0x0000000000 [0x410fd034]
...
Ubuntu 20.04.3 LTS imx8mpnavq ttymxc1

imx8mpnavq login:

Enter the Linux session by typing user for both the user name and password.