Switching for a computer and Radxa ROCK 3A
To see the output from Radxa ROCK 3A on a computer and to have debug capabilities, do the following:

Diagram for connecting USB-UART converters and Radxa ROCK 3A
bps = 115200, data bits = 8, stop bits = 1, parity = none, flow control = none for the main output.bps = 115200, data bits = 8, stop bits = 1, parity = none, flow control = none for the debug output.Define the USB port connected to the USB-UART converter used for receiving output from Radxa ROCK 3A.
To allow a computer and Radxa ROCK 3A to interact through Ethernet, perform the following actions:
dhcpcd.conf file, which is found at the path <example name>/resources/...).Connecting an eMMC module
To work with examples that use the SDHC driver, you must include a storage device: microSD card or eMMC module. By default, the Radxa ROCK 3A examples are configured to work with a microSD card. To use an eMMC module, you need to install a compatible eMMC module on the Radxa ROCK 3A board (for example: eMMC 5.1 Module 32Gb for Rock Pi). Without an included eMMC module, initialization errors for the SDCard driver (which is part of the SDHC driver stack) will be displayed in standard output when running the examples. Also, in the solution build CMake file, you must change the device index in the EXTRA_ENV property from 1 (microSD card) to 0 (eMMC) using the set_target_properties() function.
# Configuration for microSD card (used by default for the Radxa ROCK 3A)
set_target_properties(Client PROPERTIES EXTRA_ENV " MMC_DEV_NUM: '1'")
# Configuration for eMMC module
set_target_properties(Client PROPERTIES EXTRA_ENV " MMC_DEV_NUM: '0'")
Preparing a bootable SD card for Radxa ROCK 3A
If the hdd.img image was created when building the example, all you have to do is write the resulting image to the SD card. To do this, connect the SD card to the computer and run the following command:
# In the following command, path_to_img is the path to the image file
# [X] is the final character in the name of the SD card block device.
$ sudo dd of=/dev/sd[X] if=path_to_img status=progress bs=64K conv=fsync
If kos-image was created when building the example, the SD card requires additional preparations before you can write the image to it. A bootable SD card for Radxa ROCK 3A can be prepared automatically or manually. After preparing the SD card, you must copy the kos-image file from the directory <example name>/build/einit to the bootable area (FAT32 partition) of the prepared SD card.
To automatically prepare the bootable SD card, connect the SD card to the computer and run the following commands:
# To create a bootable drive image file (*.img),
# run the script:
$ sudo /opt/KasperskyOS-Community-Edition-<platform>-<version>/common/rock3a_prepare_sdcard_image.sh
# In the following command, path_to_img is the path to the image file
# of the bootable drive (this path is displayed upon completion
# of the previous command), [X] is the final character
# in the name of the SD card block device.
$ sudo dd of=/dev/sd[X] if=path_to_img status=progress bs=64K conv=fsync
Clearing the Radxa ROCK 3A flash memory
In some editions of the Radxa ROCK 3A, the flash memory may contain a bootloader that is incompatible with the card that you have prepared according to the instructions provided above.
If you see the message "SPL: failed to boot from all boot devices" when running examples on the Radxa ROCK 3A, you must clear the Radxa ROCK 3A flash memory before running the examples.
To clear the Radxa ROCK 3A flash memory:
rkdeveloptool.Instructions on installing this tool are provided in the documentation: https://docs.radxa.com/en/rock3/rock3a/low-level-dev/rkdeveloptool?host-os=debian#installation-for-rkdeveloptool
Maskrom mode:
Maskrom mode by running the following command in the terminal:$: rkdeveloptool ld
DevNo=1 Vid=0x2207,Pid=0x350a,LocationID=104 Maskrom
rkdeveloptool ef
rkdeveloptool rd