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EShar1's avatar
EShar1
Icon for New Contributor rankNew Contributor
2 days ago

Agilex 5 premium board - es version - boots with gibberish prompts

Hello dear community,

I am trying to boot linux on the Altera Agilex 5 premium board - es version with the
pre-built binaries. I followed the documentation still getting prompts in gibberish.
Following is a detailed description of the procedure I used.

My questions:
1. What am I doing wrong?
2. What should be my debugging flow steps?

Detailed description of the procedure to demonstrate the issue:
---------------------------------------------------------------------

In order to verify the Agilex 5 SoC premium baord is booting correctly, I used the
pre-build binaries per the following instructions of this link:

https://altera-fpga.github.io/rel-25.1.1/embedded-designs/agilex-5/e-series/premium/gsrd/ug-gsrd-
agx5e-premium/#configure-serial-console

I followed the paragraphs starting with the title "

Exercising Prebuilt Binaries"

This page instructs the user to download the pre-built binaries from this release:
https://releases.rocketboards.org/2025.08/gsrd/agilex5_dk_a5e065bb32aes1_gsrd/

I followed the instructions of "Booting from SD card".

The workstation is Windows 10 machine and the Terminal application is putty.

Eventually, when booting the linux per these instruction, I see the first stage boot loader (u-boot spl)

is prompting correct font, however the next booting stages are prompting gibberish.
Attached is a screenshot (202604262215screenshot.jpg).

Arm Processor
embedded peripheral
Hps Boot
Hps Debug
Sw Development

2 Replies

  • FawazJ_Altera's avatar
    FawazJ_Altera
    Icon for Frequent Contributor rankFrequent Contributor
    1 day ago

    Hello,

    Few things come to mind that are worth investigating. The fact that U-Boot SPL output looks clean but the subsequent stages go garbled is a strong hint that something changes at that handoff point; most likely the UART baud rate being re-initialized differently, or a flow control mismatch that only surfaces once the next stage takes over. Could also be something in the PuTTY config itself that happens to be compatible with how SPL sets things up but not with what comes after.

    Before anything else, it's worth double-checking your PuTTY serial settings and making sure flow control is explicitly set to None; PuTTY defaults to XON/XOFF and that alone can corrupt output on boards that don't use it. Also confirm you're on the right COM port; the Agilex 5 premium board's USB-UART adapter typically shows up as two COM ports on Windows and you want the lower-numbered one.

    To help narrow this down further, could you share the following?

    • Does the terminal show the same behavior every time you run? Like clean text outputs then garbled?
    • Your exact PuTTY serial settings: baud rate, data bits, stop bits, parity, and especially flow control ( a snapshot would be good to have).
    • Which COM port you're connected to and how many show up in Device Manager when the board is plugged in.
    • How many gibberish transitions you see? is it one clean-to-garbled switch, or does it happen more than once across the boot sequence?
    • Another suggestion worth trying: If you can catch the U-Boot prompt (spam a key during SPL to interrupt autoboot), run printenv baudrate and printenv bootargs and send the output; that would tell us about what the later stages are expecting.

     

    Thank you,

    Fawaz.

    • EShar1's avatar
      EShar1
      Icon for New Contributor rankNew Contributor
      17 hours ago

      Hello Fawaz,

      Thank you for taking care.

      My answers below, in a Question-And-Answer manner:
      Q: Does the terminal show the same behavior every time you run? Like clean text outputs then garbled?
      A: Yes

      Q: Your exact PuTTY serial settings: baud rate, data bits, stop bits, parity, and especially flow control ( a snapshot would be good to have).
      A: Attached (20260428124741agilex5premium_es_putty_config.jpg)

      Q: Which COM port you're connected to and how many show up in Device Manager when the board is plugged in.
      A: When the board is plugged in, I see only one com port, (as opposed to your expectation above of having 2), COM10. It vanishes when I unplug the board.
           For mutual convenience, attached is a screenshot (20260428125702agilex5premium_es_com_port.jpg)

      Q: How many gibberish transitions you see? is it one clean-to-garbled switch, or does it happen more than once across the boot sequence?
      A: As far as I inspected the prompts, it is one clean-to-garbled switch

      Q: Another suggestion worth trying: If you can catch the U-Boot prompt (spam a key during SPL to interrupt autoboot), run printenv baudrate and printenv bootargs and send the output; that would tell us about what the later stages are expecting.
      A: I tried spamming a key during the SPL prompts, but failed to stopped the transition to gibberish prompts.