unable to send/update u-boot over serial console

      unable to send/update u-boot over serial console

      Hello,

      I am unable to send/update U-boot via serial console. The file does not transfer to the board and seems to time-out on the ACK packet.
      Besides xmodem I have also tried transferring by using the normal and robust file transfer of kermit itself but that does not work either.

      I use the following kermit config

      set line /dev/ttyUSB0
      set speed 115200
      set carrier-watch off
      set flow-control none
      set prefixing all
      set parity none
      set stop-bits 1
      set modem none
      set file type bin
      set file name lit
      set streaming off
      set protocol xmodem
      connect


      This gives the following output:


      Please select action
      'd' -> Serial download of bootloader
      'E' -> Erase flash
      'B' -> Show bad blocks
      Use NetDCUUsbLoader for USB download

      Waiting for EBoot, U-Boot, NBoot, M4 Image...

      (Back at aramis)
      ----------------------------------------------------
      C-Kermit 9.0.302 OPEN SOURCE:, 20 Aug 2011, for Linux+SSL+KRB5 (64-bit)
      Copyright (C) 1985, 2011,
      Trustees of Columbia University in the City of New York.
      Type ? or HELP for help.
      (/tftpboot/) C-Kermit>send /binary uboot.nb0
      Sending /tftpboot/uboot.nb0, 4096 blocks: Give your local XMODEM receive command now.
      Xmodem sectors/kbytes sent: 0/ 0kRetry 0: Got 55 for sector ACK
      Retry 0: Timeout on sector ACK
      Retry 0: Timeout on sector ACK
      Retry 0: Timeout on sector ACK
      Retry 0: Timeout on sector ACK
      Retry 0: Timeout on sector ACK
      Retry 0: Timeout on sector ACK
      Retry 0: Timeout on sector ACK
      Retry 0: Timeout on sector ACK
      Retry 0: Timeout on sector ACK
      Retry 0: Timeout on sector ACK
      Retry 0: Retry Count Exceeded

      Transfer incomplete
      You have to send the bytes without any protocol if you use 'd' for download.
      You can use 'a' for xmodem protocol.
      F&S Elektronik Systeme GmbH
      As this is an international forum, please try to post in English.
      Da dies ein internationales Forum ist, bitten wir darum, Beiträge möglichst in Englisch zu verfassen.