VF61 recovery mode: u-boot doesn't always stop with prompt


I have used several times the recovery mode with VF50 and VF61 modules and since few days I’m having a strange behavior with the VF61.

From windows or from linux, I’m able to load in RAM u-boot with the Toradex procedure. Then I’m opening a terminal with the COM board to finalize the update in flash.
Often, I have a “Colibri VFxx #” prompt, but sometime the u-boot automatically boot and I’m receiving error messages about failure to boot fram nand, sd and NFS.

Could you clarify what should be the behavior?

  • Is u-boot started in standard mode with its timeout? So we have to quickly connect and press a key to take control.
  • Is u-boot started in a dedicated mode and automatically stop with a prompt?