Version 28 (modified by Tim Harvey, 14 months ago) ( diff )

move U-Boot details to new page

Newport U-Boot Bootloader

Gateworks supports the U-Boot Bootloader for the Newport product family. We provide pre-built firmware images (see here) as well as source for building and/or modifying it yourself.

One of the primary features of the Bootloader is to provide access to the hwconfig environment variable that the firmware uses for initial board configuration on power-up.

see uboot for more info on U-Boot

Pre-Built U-Boot Firmware

Pre-Built U-Boot is contained inside of the Gateworks Newport boot firmware artifact here:


The U-Boot version used on the Newport boards is v2019.10 Source code is located here:

Restoring defaults

The Newport boot firmware has a copy of the original U-Boot env that was created during build time.

To restore default bootloader environment variables:

  • At the "Hit any key to stop autoboot:" prompt press any key.
  • Execute the following command:
    run restore_env && reset


The U-Boot Bootloader by convention provides a hwconfig environment variable which is used by the boot firmware (before U-Boot is loaded and executed) to configure board options at power-up. These options can include things such as:

  • miniPCIe socket functions (ie PCIe vs mSATA vs USB3.0)
  • serial configuration (ie RS232 vs RS485)

hwconfig: miniPCIe Socket Configuration

Newport board model socket options:

  • GW640x:
    • J9: USB2 and PCI (for build option for Mezzanine connector contact sales@…)
    • J10: PCI or SATA and optional USB2 (USB2 option removes it from top front panel USB connector)
    • J11: USB2 and PCI
    • J12: USB2 and USB3
  • GW630x:
    • J9: USB2 and PCI (for build option for Mezzanine connector contact sales@…)
    • J10: USB2 and PCI or SATA
    • J11: USB2 and PCI or USB3
  • GW620x:
    • J6: USB2 and PCI or USB3
    • J8: USB2 and PCI or SATA
  • GW610x:
    • J6: USB2 and PCI or SATA or USB3

Note that as PCIe, USB3.0 SS, and SATA share signals so if multiple options exist you must choose between them on those sockets using the hwconfig bootloader env variable.

If a socket is not specified in hwconfig then the PCI option will be the default.

You can get/set the hwconfig variable within the U-Boot bootloader but you must reboot the board for it to take effect as the variable is acted upon in the Secondary Program Loader (SPL).


  • GW620x:
    • J6 USB3 (removes PCI)
      setenv hwconfig 'j6:usb3'; saveenv
    • J6 PCIe and USB2 (removes USB3)
      setenv hwconfig ; saveenv
  • GW640x:
    • J10 SATA
      setenv hwconfig 'j10:sata'; saveenv
    • J10 PCIe and USB2 (removes USB2 from top front panel USB connector)
      setenv hwconfig 'j10:pci,usb2'; saveenv
  • GW630x:
    • J10 PCIe, J11 PCIe (default)
      setenv hwconfig 'j10:pci;j11:pci'; saveenv
    • J10 mSATA, J11 USB3.0
      setenv hwconfig 'j10:sata;j11:usb3'; saveenv
    • J9/J10 disabled, J11 PCIe
      setenv hwconfig 'j9:disabled;j10:disabled;j11:pci'; saveenv

You can see that the hwconfig configuration took place by watching the output of the BDK during boot. For example:

Gateworks Newport SPL (3442703 Wed Jun 6 20:26:30 UTC 2018)

GSC     : v52 0xbf2d WDT:disabled board temp:38C
RTC     : 506646
Model   : GW6304-C
MFGDate : 03-28-2018
Serial  : 776375
DTB     : gw6304.dtb
SoC     : CN8030-1500BG676-SCP-P12-G 1024KB 1500/550MHz 0xa2 Pass 1.2
MMC0    : eMMC
MMC1    : not detected
Boot    : eMMC non-trusted
DRAM    : 2048 MB, 1333 MT/s, DDR4 UDIMM
J9      : PCI
J10     : SATA
J11     : USB3
QLM0    : PCIE_1X1@5000MHz
QLM1    : SGMII_1X1@1250MHz
QLM2    : DISABLED@5000MHz
QLM3    : SATA_2X1@6000MHz
Serial  : 2x RS232 without flow control
Hit any key to stop autoboot:  0
GW6304-C> print hwconfig
  • The above shows that J9 is configured for PCI, J10 for SATA, and J11 for USB3

Note that hwconfig is also used for serial configuration so care should be taken to preserve that configuration if used

hwconfig: serial Configuration

Many boards in the Newport product family provide a 5-pin off-board serial connector that provides the following options:

  • 1x RS485 FD (UART2)
  • 1x RS485 HD (UART2)
  • 1x RS232 w/ hardware flow control (UART2)
  • 2x RS232 w/o hardware flow control (UART2/UART3)

By default 2x RS232 with no flow control is enabled. To configure a different option use the hwconfig U-Boot env variable. The mode property of the serial option defines the initial configuration of the serial port(s). If RS485 is selected by the mode property the term property will select whether or not on-board termination is enabled.

The mode property can have the following values:

  • rs232 - 2x RS232 (UART2/UART3) without hardware flow control (default if not specified)
  • rs232_dtr - RS232 (UART2) with hardware flow control
  • rs485_hd - RS485 half-duplex
  • rs485_fd - RS485 full-duplex


  • Note that setting hwconfig currently requires saveenv to be ran twice
  • Enable RS485 half duplex no on-board termination
    setenv hwconfig "serial:mode=rs485_hd,term=no"; saveenv
  • Enable RS485 full duplex with on-board termination
    setenv hwconfig "serial:mode=rs485_fd,term=yes"; saveenv
  • Enable RS232 with hardware flow-control:
    setenv hwconfig "serial:mode=rs232_dtr"; saveenv

Note that hwconfig is also used for pcie configuration so care should be taken to preserve that configuration if used

Editing the environment

If you would like to add your own arguments to the U-boot environment changes can be made to this file:

Note: See TracWiki for help on using the wiki.