Toradex SMARC iMX95 with 5G RTL8251B ethernet integration issue

Technical Support
, , , , , , ,
1

Hi,

I’m working on the RTL8251B integration with the imx95 toradx som. We are using the latest version of som v1.2A only. In that, we have sucessfully integrated the RTL8251B 5G ethernet with phy-mode 5g-base-r but in this the MAC allocation was random allocating and if we set the static ip also not working, ping is unreachable. We tried the all the ways from our side but we haven’t sort out this issue. If we use any other mode also we are getting the same issue. If we use usxgmii phy mode means, the mdio is not working even the end2 node also not created. I will attach all the logs for your reference. Could you please assist on this issue?

Screenshot from 2026-08-27 19-40-56
Screenshot from 2026-08-27 19-40-56585×222 19.4 KB

Screenshot from 2026-08-27 19-40-47
Screenshot from 2026-08-27 19-40-47748×259 30.9 KB

Screenshot from 2026-08-27 19-39-14
Screenshot from 2026-08-27 19-39-14679×564 62.6 KB

Screenshot from 2026-08-27 19-38-59
Screenshot from 2026-08-27 19-38-59986×437 102 KB

Screenshot from 2026-08-27 12-48-56
Screenshot from 2026-08-27 12-48-56916×396 44.8 KB

2

Hi, I’m the Toradex AI Assistant.

I might make mistakes or occasionally get you wrong. Our support team will step in if needed.

I can see you’re working with the SMARC iMX95 V1.2A module and experiencing issues integrating the RTL8251B 5G Ethernet PHY. However, I need to clarify a few important points about your setup.

Hardware Clarification Needed

First, could you confirm which exact version of Torizon OS or BSP you are running? You can use the tdx-info command to get detailed information about your system.(1)

Known Hardware Considerations for V1.2A

The SMARC iMX95 V1.2A that you mentioned is documented to have specific changes compared to earlier versions. According to the revision history, V1.2A includes fixes for boundary scan and JTAG debugging issues, and the eMMC part number was changed from Skyhigh S40FC032C3B1I00000 to Micron MTFC32GBCAQTC-IT.(1)

Ethernet Interface Information

The SMARC iMX95 module features up to 2 Gigabit Ethernet PHYs with IEEE1588 support directly on the module, and a third Ethernet MAC with a SGMII/USXGMII interface available for incorporating a 2.5 or 10-Gigabit Ethernet PHY on the carrier board.(2)

Regarding Your Integration Issue

The specific RTL8251B PHY integration you’re attempting involves carrier board-level implementation using the SGMII/USXGMII interface. From your description:

  1. Random MAC allocation - This suggests the network interface is being created but lacks proper configuration
  2. MDIO not working with USXGMII - This indicates potential device tree configuration issues
  3. Static IP not working - This could be related to PHY link establishment

Unfortunately, the available documentation does not contain specific device tree examples or configuration guidance for integrating external 5G/10G Ethernet PHYs like the RTL8251B with the SMARC iMX95’s SGMII/USXGMII interface.

Recommended Next Steps

To properly assist you, I would need:

  • Your exact OS version (Torizon OS or BSP version)
  • Your device tree configuration for the RTL8251B
  • Complete dmesg logs showing the PHY initialization
  • Your carrier board design details

For complex carrier board integrations involving high-speed Ethernet PHYs, I recommend:

Visit Community to share your device tree configuration and detailed logs where the engineering team can provide specific guidance.

Visit GitHub to review reference device tree implementations for similar PHY integrations.

Would you like a general answer based on common Ethernet PHY integration practices, or would you prefer to gather the additional information first?

Best regards,
Toradex AI Assistant.

Did you like my answer? :+1: :-1:

If I answered your question, please tick the “Solution” checkbox.

For follow-up questions to me, please use @ToradexAI in your post.