Replacing the default boot logo of Nvicia Jetson modules with a custom one.

Need to have a correct JetPack version installed on the host OS (a workstation, not the Jetson module itself).

Key Concepts

• The boot logo image is saved in the bootloader.
• The boot logo is loaded and displayed by bootloader before the kernel is loaded.
• Thus, it cannot be done by building a custom kernel or a custom image.
• It can be done only by flashing the bootloader in the recovery mode.
• The logo image is compressed in LZ format. The default compressed blob is: Linux_for_Tegra/bootloader/bmp.blob

HowTo

Prepare 3 custom logo images in different sizes: 640x480, 1280x720, 1920x1080. Copy the images under the Linux_for_Tegra/tools/bmp-splash/ folder.

<path-to-sdk>/Linux_for_Tegra/tools/bmp-splash/
├── bmp-blob-README.txt
├── BMP_generator_L4T.py
├── config_file.example
├── genbmpblob_L4T.sh
├── custom-logo-480.bmp
├── custom-logo-720.bmp
└── custom-logo-1080.bmp

Edit the config_file.example like this.

custom-logo-480.bmp nvidia 480;
custom-logo-720.bmp nvidia 720;
custom-logo-1080.bmp nvidia 1080

Install liblz4-tool if it’s not on the host system. And confirm its installtion path is /usr/bin/lz4c. This is used for blob compression script. We will not use liblz4-tool directly.

$ sudo apt install liblz4-tool
$ whereis lz4c
lz4c: /usr/bin/lz4c /usr/share/man/man1/lz4c.1.gz

Generate custom-bmp.blob

$ cd <path-to-sdk>/Linux_for_Tegra/tools/bmp-splash/
$ OUT=$PWD ./genbmpblob_L4T.sh t194 ./config_file ./BMP_generator_L4T.py /usr/bin/lz4c custom-bmp.blob

Note that the general command format is like the following, and need to use correct chip name for the Jetson module.

# Jetson Nano - <chip> = t194
# Jetson Xavier NX - <chip> = t210
# ...
$ OUT=$PWD ./genbmpblob_L4T.sh <chip> <product config file> <path to blob_generator> [ <path to lz4c> ] <output file>

Boot the Jetson module in a recovery mode by plugging a jumper on the Jetson module dev boards. Note that jumper positions may vary for each dev board types.

$ cd <path-to-sdk>/Linux_for_Tegra/
$ sudo ./flash.sh -r -k BMP --image ./tools/bmp-splash/custom-bmp.blob jetson-nano-emmc mmcblk0p1

Note that the general command format is like the following, and need to use correct board name for the Jetson module.

# Jetson Nano 4GB eMMC - <board> = jetson-nano-emmc
# Jetson Nano 4GB SD card - <board> = jetson-nano-devkit
# Jetson Xavier NX eMMC - <board> = jetson-xavier-nx-en715
# ...
$ sudo ./flash.sh -r -k BMP --image <path to custom logo blob> <board> mmcblk0p1

Now turn off the Jetson module, remove recovery jumper, and boot into normal mode. The new log should be shown!

Troubleshooting

There are many similar articles and blogs related to customize Jetson module logo. Many errors are related to the flashing step, by choosing incorrect board name. For more information about board names, the best resource is Nvidia’s official documentation: Flashing and Booting the Target Device