Updating UbiSwitch from BloxOSLite v1.0.x over UART

BotBlox Hardware
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This topic was migrated from the BotBlox ticketing system after being summarized and anonymized.

Question

We have a UbiSwitch 10G BaseBoard Rev B running an early BloxOSLite v1.0.x release and want to update it to a newer firmware version.

The CLI works normally over UART using 115200 baud, 8 data bits, no parity, and 1 stop bit. However, when we start the update with mcumgr-client, the board appears to interpret the SMP frames as text entered into the CLI.

This makes it look like the existing firmware does not support SMP or mcumgr.

Can BloxOSLite v1.0.x be updated over UART, or does updating an older unit require SWD access and an external programmer?

Answer

BloxOSLite v1.0.x can be updated over UART. An SWD programmer is not normally required.

The important detail is that the board only accepts the firmware update during a five-second window after startup. If the update is not started within that window, the board continues booting and enters the normal CLI.

Once the CLI is active, incoming SMP frames are treated as terminal input. This can make it appear that SMP support is missing, even though the UART update method is available.

How to update the firmware

  1. Connect the board’s UART interface to the host computer.

  2. Configure the serial connection for:

    • 115200 baud

    • 8 data bits

    • No parity

    • 1 stop bit

  3. Prepare mcumgr-client and the correct firmware image before restarting the board.

  4. Power-cycle or reset the board.

  5. Start the firmware update within the five-second update window.

If the normal BloxOSLite CLI appears before the transfer begins, the update window has been missed. Restart the board and try again, starting the update earlier.

Why the SMP data appears as text

The UART interface is shared between the firmware-update process and the normal command-line interface.

During the startup update window, the board listens for the firmware-update protocol. After that window expires, UART input is passed to the CLI instead. Binary SMP frames may therefore appear as unreadable text or invalid commands.

This behavior does not necessarily mean that the SMP server is absent from the installed firmware. It usually means that the update was attempted after the five-second window closed.

Is SWD access required?

No. For a normally functioning board running BloxOSLite v1.0.x, the supported UART update process should be used first.

SWD access is generally only relevant for recovery or development situations where the normal UART update path cannot be used. It should not be necessary simply because the board is running an older v1.0.x release.

Troubleshooting checklist

If the update does not start:

  • Confirm that the correct serial port is selected.

  • Confirm the UART settings are 115200 8N1.

  • Close any serial terminal that may already be using the port.

  • Prepare the update command before resetting the board.

  • Start the transfer immediately after reset or power-up.

  • If the CLI appears, reset the board and retry within the five-second window.

  • Confirm that the firmware image is intended for the exact UbiSwitch hardware revision being updated.

The key point is timing: BloxOSLite v1.0.x supports UART firmware updates, but the transfer must begin during the five-second startup window.