Jetson Module Adaptation and Bring-Up: Jetson Xavier NX Series

This topic is for engineers who are developing production software for an NVIDIA Jetson Xavier NX series module. It describes how to port NVIDIA Jetson Linux and Bootloader from a Jetson Xavier NX Developer Kit to a custom hardware platform and bring up a working system on the new platform.

The examples described include code for the Jetson Xavier NX Developer Kit (P3518).

For information on customizing the configuration files, see the section MB1 Platform Configuration.

Two other topics are closely related to this one:

Board Configuration

Jetson Xavier NX series has three variants:

  • Jetson Xavier NX (development, P3668-0000), with 8 GB of RAM and an on-module microSD card socket. Is intended only for software development, and is sold only as a component of Jetson Xavier NX Developer Kit. You can program it by flashing a microSD card in place, or by flashing it on a host computer and then installing it on the module.

  • Jetson Xavier NX (production, P3668-0001), with 8 GB of RAM but no microSD card socket. This module is sold as a separate unit. It is intended for production use but may also be used in a Jetson Xavier NX Developer Kit. You program it in the conventional way, by flashing software to on-board eMMC memory.

  • Jetson Xavier NX 16GB (P3668-0003), with 16 GB of RAM. This variant is identical to P3668-0001 in all respects except RAM size.

Jetson Xavier NX Developer Kit, P3518, includes a P3509-0000 reference carrier board as well as the P3668-0000 SOM. The SOM and carrier board each have an EEPROM where the board ID is saved. The SOM can be used without any software configuration modifications.

Jetson Xavier NX series modules have a provision for attaching a heatsink or fansink. The module provided with a Jetson Xavier NX Developer Kit has a fansink already attached. See the Jetson Xavier NX Thermal Design Guide for guidance on designing or procuring a thermal solution for production Jetson Xavier NX series modules.

Before using the SOM with a carrier board other than P3509, you must change the kernel device tree, MB1 configuration, ODM data, and flashing configuration to accommodate the new carrier board instead of P3509. An EEPROM ID for your custom board is not required.

You can also use the reference carrier board P3449-0000 (included in the Jetson Nano Developer Kit) with a Jetson Xavier NX series module. The Jetson Linux installer detects the type of module and carrier board and automatically installs the appropriate drivers and other device-specific components.

Board Naming

To support a Jetson Xavier NX series module with your custom carrier board, you must assign the module/carrier board combination a board name. This name must consist of lower case letters, numerals, hyphens, and underscores. You must set the board name in the environment variable BOARD on your host system.

Some examples of valid board names are p3509-0000+p3668-0000, p3518-0000-devkit, and devboard.

The installation process uses the board name in filenames and pathnames, including names in the device tree and proc file system.

The placeholder <board> is used to represent the board name throughout this topic. Where a command contains <board>, substitute the name of your custom board.

Note

Do not modify files whose filenames and pathnames contain your system’s default board name. The default board name refers to the carrier board provided with your Jetson developer kit. If it appears in a file’s name, that file contains code or data that is specific to that board. Make copies of such files that are named with your custom board’s board name, and modify them to support your custom board.

Root File System Configuration

Jetson Linux can use any standard or customized Linux root file system (rootfs) that is appropriate for its targeted embedded applications.

However, certain settings must be configured in the rootfs’s boot-up framework to set default configuration after boot, or some of the core functionalities will not run as expected.

For example:

  1. The nv.sh and nvfb.sh boot-up scripts do some platform-specific configuration in the kernel.

  2. The Xorg and X libraries must be correctly configured for the target device.

  3. The nvpmodel clock and frequency must be configured for the target device.

Jetson Linux provides these rootfs configurations and customizations in this directory and its subdirectories:

Linux_for_Tegra/nv_tegra/

You must incorporate the relevant customization for your target rootfs from this location.

Note

For the sample Ubuntu root file system provided by NVIDIA, this customization is applied using the script Linux_for_Tegra/apply_binaries.sh.

MB1 Configuration Changes

Multiple .cfg files define boot time configuration of the hardware. They are applied by Bootloader. The MB1 boot configuration tables are available at:

<l4t_top>/bootloader/t186ref/BCT

Where <l4t_top> is the top-level BSP flashing directory.

Pinmux Changes

If your carrier board schematic differs from that of the reference carrier board in Jetson Xavier NX Developer Kit, you must change the pinmux configuration applied by the software.

To define your board’s pinmux configuration, download the Jetson Xavier NX pinmux table from the Jetson Download Center. Be sure to get the right version of the table for your SOM.

The pinmux table is a spreadsheet that:

  • Shows the locations and default pinmux settings

  • Acts as a data source for software that defines the pinmux settings in the source code or device tree

You must customize the spreadsheet for the configuration of your board, then convert the .dtsi file generated by Excel to a .cfg file. For instructions, see the README file at:

Linux_for_Tegra/kernel/pinmux/t19x/

You must perform the same conversion for gpio.dtsi and padvoltage.dtsi.

GPIO Changes

If you designed your own carrier board, to translate from SOM connector pins to actual GPIO numbers you must understand the GPIO mapping formula below. The translated GPIO numbers can be controlled by the driver.

To check a GPIO number

This example procedure checks the GPIO number of signal name SPI0_CS1.

  1. Open the Jetson Xavier NX pinmux table. (See Pinmux Changes, above.)

  2. Search the table for SPI0_CS1.

  3. Confirm that the Customer Usage field contains the GPIO name GPIO3_PZ.07.

  4. Search PZ.07 using the following command:

    cat /sys/kernel/debug/gpio | grep PZ.07
    
  1. For example Output:

    gpio-xxx (PZ.07               )
    
  2. GPIO number of SPI0_CS1 is xxx.

Note: To use a pin as GPIO, make sure that E_IO_HV field is disabled in corresponding pinmux register of the GPIO pin. You can disable the field 3.3V Tolerance Enable in pinmux spreadsheet and reflash the board with the updated pinmux file.

PMIC Changes

The PMIC configuration file configures the initial PMIC in the P3668 SOM. It also defines some GPIO expander-based GPIO regulator settings in the P3509 carrier board configurations. Review this configuration file to replace any references to the P3509 carrier board with references to your custom board. If required, include any regulator information to enable this file.

For example, the following settings configure PMIC to turn on SD4 on I2C address 0x3c. The example is from the configuration file tegra194-mb1-bct-pmic-p3668-0001-a00.cfg:

######################## System Configurations ####
# PMIC FPS to turn SD4 (VDD_DDR_1V1) on in time slot 0
# PMIC FPS to set GPIO2 (EN_DDR_VDDQ) high in time slot 1
# Set SLPEN = 1 and CLRSE on POR reset
pmic.system.block[0].type = -1; # I2C
pmic.system.block[0].controller-id = 4;
pmic.system.block[0].slave-add = 0x78; # 7BIt:0x3c
pmic.system.block[0].reg-data-size = 8;
pmic.system.block[0].reg-add-size = 8;
pmic.system.block[0].block-delay = 10;
pmic.system.block[0].commands[0].0x53.0x38 = 0x00; #_SD4 FPS UP slot 0
pmic.system.block[0].commands[1].0x55.0x38 = 0x10; #_GPIO2 FPS UP slot 2
pmic.system.block[0].commands[2].0x41.0x1C = 0x1C; #_SLPEN=1, CLRSE = 11

Porting the Linux Kernel

It is assumed that you are using a P3668 SOM connected to an unmodified P3509 carrier board; the QSPI, PMIC, DDR, and routing of lines are all unchanged. The modifications you are making are for the SOM and the carrier board. Consequently, based on the peripherals present on your carrier board, you can modify the .dts files by disabling/enabling the controllers and changing the supplies.

To port the kernel configuration code (the device tree) to your platform, modify one of the distributed configuration files to describe the design of your platform.

The configuration files are available at:

<top>/hardware/nvidia/platform/t19x/
<top>/hardware/nvidia/soc/t19x

The final DTB file used is:

tegra194-p3668-0000-p3509-0000.dtb

By reading the above file, you see which other .dtsi files are referenced by include statements. The following table describes common .dtsi files that may be modified to reflect hardware design changes.

Types of Changes

DTSI Filename or location

Power supply changes

tegra194-power-tree-p3668.dtsi

Regulator parameter changes

tegra194-spmic-p3668.dtsi

Display panel and node changes

For details, see the topic Display Configuration and Bringup.

ODM data based feature configuration

tegra194-plugin-manager-p3668.dtsi

NVIDIA SoC controller state to enable/disable a controller

soc/t19x/kernel-dts/tegra194-soc/

Panels related .dts files

platform/tegra/common/kernel-dts/panels/

Verify that no other .dts or .dtsi file, including these .dts files, overrides any changes you make.

As a best practice, create your own set of .dts files based on the NVIDIA® Jetson AGX Xavier™ files already present. Rename your newly created files to the name of your board.

Note

Use fdtdump or dtc to generate a .dts file from the final .dtb file and check whether your changes have taken effect.

The command usage is:

$ dtc -I dtb -O dts tegra194-p3668-all-p3509-0000.dtb > tegra194-p3668-all-p3509-0000.dts
$ fdtdump dts tegra194-p3668-all-p3509-0000.dtb >tegra194-p3668-all-p3509-0000.dts

PCIe Controller Configuration

The PCIe host controller is based on Synopsis Designware PCIe intellectual property, and thus inherits all the common properties defined in the information file at:

$(KERNEL_TOP)/nvidia/Documentation/devicetree/bindings/pci/nvidia,tegra19x-pcie.txt

PCIe Controller Features

Jetson Xavier NX series has two PCIe controllers with these specifications:

  • Lane width and speed:

    • C5: x4 and Gen4

    • C4: x1 and Gen3

  • Controllers: Controllers C0, C4 and C5 support dual mode, that is, can be configured as endpoints.

  • ASPM: All controllers support ASPM.

The Jetson Xavier NX PCIe configuration is:

  • C5: x4

  • C4: x1

These PCIe slots available on Jetson Xavier NX series:

  • M.2 Key M: C5 controller operates in x4 mode. Any M.2 Key M form factor NVMe cards can be connected.

  • M.2 Key E: C4 controller operates in x1 mode. Any M.2 Key E form factor cards like Wi-Fi can be connected.

For information about Jetson Xavier NX series-specific PCIe controller configuration, see the device tree documentation file at:

$(KERNEL_TOP)/nvidia/Documentation/devicetree/bindings/pci/nvidia,tegra19x-pcie.txt

This file covers topics that include configuring maximum link speed and link width, and advertisement of different ASPM states.

Porting Universal Serial Bus

The Jetson Xavier NX series modules can support one enhanced SuperSpeed Universal Serial Bus (USB) port and up to three High Speed USB ports. The Jetson Xavier NX P3509 carrier board is designed and verified for one USB3.1 port. If you design your own carrier board, verify the compatibility between P3509 and your own board by consulting the NVIDIA team.

USB Structure

An enhanced SuperSpeed USB port has nine pins:

  • VBUS.

  • GND.

  • D+.

  • D−.

  • Two differential signal pairs for SuperSpeed data transfer.

  • One ground (GND_DRAIN) for drain wire termination and managing EMI, RFI, and signal integrity.

USB SuperSpeed port pinout

The D+/D− signal pins connect to UTMI pads. The SSTX/SSRX signal pins connect to UPHY and are handled by a single UPHY lane. As UPHY lanes are shared between PCIE, SATA, UFS, and XUSB, UPHY lanes must be assigned according to the custom carrier board’s requirements.

Required Device Tree Changes

This section gives step-by-step guidance for checking schematics and configuring USB ports in the device tree. All of the examples are based on the design of the Jetson Xavier NX P3509 carrier board.

For a Host-Only Port

This section uses U7, a USB 3.1 Gen2 Realtek Enhanced SuperSpeed on-board hub, model number RTS5489-GR (hereafter “Realtek hub”) as an example of a host-only port.

Go Through the Schematics

Note

The P3509 carrier board’s schematic file is included in the Jetson Xavier NX Developer Kit ​Carrier Board ​Design ​Files, available from the Jetson Download Center.

Check the Realtek hub on the P3509 carrier board and find the socket location wired to the P3668 SOM.

  • USB2 signal pins D+/D- (USP_D_P/USP_D_N) wire out from U7 and lead to module socket pins 117 (USB1_D) and 115 (USB1_D).

    USB2 signal pins from U7
  • USB3 differential pairs (USP_TX_* and USP_RX_*) wire out from U7 and lead to module socket pins 161 (SBSS_RX) and 168 (USBSS_TX).

USB3 signal pins from U7

Through the schematic, you can conclude that for U7:

  • The USB2 signal pair is wired to UTMI pad 1 (USB2 port 1).

  • The USB3 signal pairs are wired to UPHY lane 1 (USB 3.1 port 2).

The xusb_padctl Node

The device tree’s xusb_padctl node follows the conventions of pinctrl-bindings.txt. It contains two groups, named pads and ports, which describe USB2 and USB3 signals along with parameters and port numbers. The name of each parameter description subnode in pads and ports must be in the form <type>-<port_number>, where <type> is "usb2" or "usb3", and <port_number> is the associated port number.

The properties of the pads subnode are:

  • nvidia,function: A string containing the name of the function to mux to the pin or group. Must be "xusb".

The properties of the ports subnode are:

  • mode: A string that describes USB port capability. A port for USB2 must have this property. It must be one of these values:

    • host

    • peripheral

    • otg

  • nvidia,usb2-companion: USB2 port (0, 1, or 2) to which the port is mapped. A port for USB3 must have this property.

  • nvidia,oc-pin: The overcurrent VBUS pin the port is using. The value must be positive or zero.

    Note

    Overcurrent detection and handling for U7, a Realtek hub on the P3509 carrier board, are controlled by the hub itself. Therefore, you need not set this property.

  • vbus-supply: VBUS regulator for the corresponding UTMI pad. Set to &battery_reg for a dummy regulator.

    Note

    The Realtek hub is always connected to the root hub port on a P3509, so you need not control hub power. You just need enable it with VDD_3V3_SYS. Therefore, you must set dummy regulators for U7 on the P3509 carrier board.

For the detailed information about xusb_padctl, see the documentation at:

kernel/kernel-5.10/Documentation/devicetree/bindings/phy/nvidia,xusb-padctl.txt

As an example, consider U7, the Realtek hub, which is always connected to USB2 port 1 and USB3 port 2 on the root hub. Create a pad/port node and property list for U7 based on the device tree structure described above:

xusb_padctl: xusb_padctl@3520000 {
    ...
    pads {
        usb2 {
            lanes {
                usb2-1 {
                    nvidia,function = "xusb";
                    status = "okay";
                };
                ...
            };
        };
        usb3 {
            lanes {
                usb3-2 {
                    nvidia,function = "xusb";
                    status = "okay";
                };
            };
        };
    };
    ports {
        ...
        usb2-1 {
            mode = "host";
            vbus-supply = <&battery_reg>;
            status = "okay";
        };
        ...
        usb3-0 {
            nvidia,usb2-companion = <1>;
            status = "okay";
        };
    };
};
Under the xHCI Node

The Jetson Xavier NX xHCI controller complies with xHCI specifications, which support both USB 2.0 High Speed / Full Speed / Low Speed and USB 3.1 SuperSpeed protocols.

The properties of the node are:

  • phys: Must contain an entry for each entry in phy-names.

  • phy-names: Must include an entry for each PHY used by the controller. Names must be in the form <type>-<port_number>, where <type> is "usb2" or "usb3", and <port_number> is the associated port number.

  • nvidia,xusb-padctl: A pointer to the xusb-padctl node.

For detailed information about xHCI, see the documentation at:

kernel/kernel-5.10/Documentation/devicetree/bindings/usb/nvidia,tegra-xhci.txt

Consider U7, the Realtek hub, as an example. Create an xHCI node and property list for U7 based on the device tree structure described above:

tegra_xhci: xhci@3610000 {
    ...
    phys = <&{/xusb_padctl@3520000/pads/usb2/lanes/usb2-1}>,
           <&{/xusb_padctl@3520000/pads/usb3/lanes/usb3-2}>;
    phy-names = "usb2-1", "usb3-2";
    nvidia,xusb-padctl = <&xusb_padctl>;
    status = "okay";
    ...
};

For an OTG (On-The-Go) Port

USB On-The-Go, which is often abbreviated USB OTG or just OTG, is a specification that allows USB to act as a host or a device in the same port. A USB OTG port can switch back and forth between the roles of host and device.

This section takes J5, USB2.0 Micro B connector, as an example of an OTG port.

An OTG port adds a fifth pin to the standard USB connector, called the ID pin. An OTG cable has an A-plug on one end and a B-plug on the other end. The A-plug’s ID pin is grounded, while the B-plug’s ID pin is floating. A device with an A-plug inserted becomes and OTG A-device (a host), and a device with a B-plug inserted becomes a B-device (a device).

OTG port pinout

Note

Because its ID pin is floating, J5 is fixed in the device role in the Jetson Xavier NX Developer Kit. It cannot function as a host, for example, to connect a flash drive, a keyboard, or a mouse.

Go Through the Schematics

Note

The P3509 carrier board’s schematic file is included in Jetson Xavier NX Developer Kit Carrier Board Design Files, available from the Jetson Download Center.

Check the USB connectors on the P3509 carrier board and find the socket location wired to the P3668 SOM.

  • USB2 signal pins D+/D− (DP and DN) wire out from J5 and lead to pin 111 (USB0_D) and pin 109 (USB0_D) on the SOM socket.

USB2 signal pins from J5

The USB 2.0 Micro B connector, J5, supports only HighSpeed mode, and does not have USB3 signal pairs.

From the schematic, you can see that for J5:

  • The USB2 signal pair is wired to UTMI pad 0 (USB2 port 0).

The USB Connector Class

A USB connector class represents a physical USB connector. It should be a child of a USB interface controller or a separate node when it is attached to the MUX and USB interface controllers.

Generally, port switching between the roles of an OTG port is controlled by the host driver (xHCI) and device driver (xUDC), and can be defined by the state of the ID pin and the VBUS_DETECT pin.

Taking GPIO_M3 as the VBUS_DETECT pin and GPIO_Q0 as the ID pin, for example:

  1. Find the corresponding GPIO states on the VBUS_DETECT pin and the ID pin.

    Generally, the ID pin is designed as internal pull high (logical high). With an A-plug connected the ID pin is pulled to ground (logical low), while with a B-plug connected or no cable connected it remains logical high.

    The operation of the VBUS_DETECT pin depends on the device’s design. Consider the schematic in the following diagram, for example:

    OTG Role Switching

    With a B-plug connected, VBUS_DETECT is logical low, because VBUS is provided from an external power supply. When no cable is connected, it is logical high.

    Note

    VBUS_DETECT is initially logical high, then logical low because VBUS is provided by the host controller. Therefore, the state of the VBUS_DETECT pin does not matter when the OTG port is operating in host mode.

  2. Create the table of GPIO states and their corresponding output cable states:

    GPIO_Q0 (ID)

    GPIO_M3 (VBUS_DETECT)

    Data Role

    1

    1

    Not Connected

    0

    0

    HOST

    0

    1

    HOST

    1

    0

    DEVICE

Under the Connector Node

Port switching between the roles of an OTG port is defined by the state of the ID pin and the VBUS_DETECT pin and the settings of the USB connector class.

The properties of the extcon node are:

  • compatible: Value must be "Value must be "gpio-usb-b-connector".

  • Label:Symbolic name for the connector.

  • type: Size of the connector, should be specified in case of non-full size ‘usb-a-connector’ or ‘usb-b-connector’ compatible connectors.

  • id-gpios:An input gpio for USB ID pin.

  • vbus-gpios: An input gpio for the USB VBus pin, used to detect the presence of VBUS 5V.

  • cable-connected-on-boot: Name of the output cable connected on boot.

    It should be USB_ROLE_NONE, USB_ROLE_HOST, and USB_ROLE_DEVICE. If not specified, the system assumes that no cable is to be connected.

  • wakeup-source: A Boolean; true if the device can wake up the system.

    For detailed information about USBConnector, see the documentation at:

    ``kernel/kernel-5.10/Documentation/devicetree/bindings/connector/usb-connector.yaml``
    
  • Create a USBConnector device node and property list based on the device tree structure described above and the table of GPIO states and corresponding output cable states for GPIO_Q0 and GPIO_M3:

    vxusb_padctl: xusb_padctl@3520000 {
    ...
          ports {
                    usb2-0 {
                    ...
                    Connector {
                      compatible = "gpio-usb-b-connector";
                      label = "micro-USB";
                      type = "micro";
                      vbus-gpio = <&tegra_main_gpio
                    TEGRA194_MAIN_GPIO(M, 3) GPIO_ACTIVE_LOW>;
                      id-gpio = <&tegra_main_gpio
                    TEGRA194_MAIN_GPIO(Q, 0)
                    GPIO_ACTIVE_HIGH>;
                     };
                     ...
                 };
            };
            ...
    

The USB 2.0 Micro B connector, J5, has the connector’s ID pin floating and the VBUS_DETECT pin of the connector wired out to GPIO00, which corresponds to GPIO_PZ1. As a result, J5 can only function in the device role.

USB 2.0 Micro B connector J5 has the connector's ID pin floating

This table describes the GPIO states on J5 and the corresponding output: cable states:

GPIO_PZ1 (VBUS_DETECT)

Data Role

1

Not Connected

0

Device

This is the USBConnectorClass device node and property list based on the device tree structure and the table of GPIO states and corresponding output cable states for GPIO_PZI that is customized for Jetson Xavier NX, where the ID pin that is floating the port is fixed in the device role:

xusb_padctl: xusb_padctl@3520000 {
...
      ports {
                  usb2-0 {
                  ...
                  Connector {
                    compatible = "gpio-usb-b-connector";
                    label = "micro-USB";
                    type = "micro";
                    vbus-gpio = <&tegra_main_gpio
                  TEGRA194_MAIN_GPIO(Z, 1) GPIO_ACTIVE_LOW>;
                   };
                   ...
            };
      };
      ...
};

Note

Check the pinmux spreadsheet for the GPIO that corresponds to the ID pin and VBUS_DETECT pin. Check the pinmux spreadsheet for the GPIO that corresponds to the ID pin and VBUS_DETECT pin.

Under the xusb_padctl Node

xusb_padctl settings for an OTG port are the same as for a host-only port except that the mode must be "otg".

Taking J5, the USB 2.0 Micro B connector, as an example, create a pad/port node and property list:

xusb_padctl: xusb_padctl@3520000 {
    ...
    pads {
        usb2 {
            lanes {
                usb2-0 {
                    nvidia,function = "xusb";
                    status = "okay";
                };
                ...
            };
        };
        ...
    };
    ports {
        usb2-0 {
            mode = "otg";
            vbus-supply = <&battery_reg>;
            usb-role-switch;
            status = "okay";
            Connector {
                compatible = "gpio-usb-b-connector";
                label = "micro-USB";
                type = "micro";
                vbus-gpio = <&tegra_main_gpio
                TEGRA194_MAIN_GPIO(Z, 1) GPIO_ACTIVE_LOW>;
            };
        };
        ...
    };
};
Under the xHCI Node

The xHCI settings for an OTG port are the same as for a host-only port:

Taking the USB 2.0 Micro B connector, J51, as an example, create an xHCI node and property list based on the device tree structure described in Under the xHCI Node for a host-only port:

tegra_xhci: xhci@3610000 {
    . . .
    phys = <&{/xusb_padctl@3520000/pads/usb2/lanes/usb2-0}>;
    phy-names = "usb2-0";
    nvidia,xusb-padctl = <&xusb_padctl>;
    status = "okay";
    . . .
};
Under the xUDC Node

The Jetson Xavier NX xUDC controller supports both USB 2.0 High Speed  / Full Speed and USB 3.1 SuperSpeed protocols.

  • charger-detector: USB charger detection support. Must be the phandle of the USB charger detection driver DT node.

  • phys: An array; must contain pointers to the nodes that define each PHY in phy-names.

  • phy-names: An array; must contain an entry for each PHY used by the controller. Names must be in the form <type>-<port_number>, where <type> is one of "usb2" or "usb3", and <port_number> is the associated port number.

  • nvidia,xusb-padctl: A pointer to the xusb-padctl node.

For detailed information about xUDC, see the documentation at:

kernel/kernel-5.10/Documentation/devicetree/bindings/usb/nvidia,tegra-xudc.txt

Taking J5, the USB 2.0 Micro B connector, as an example, create an xUDC node and property list for J5 based on the device tree structure described above:

tegra_xudc: xudc@3550000 {
    phys = <&{/xusb_padctl@3520000/pads/usb2/lanes/usb2-0}>;
    phy-names = "usb2-0";
    nvidia,xusb-padctl = <&xusb_padctl>;
    status = "okay";
};

Flashing the Build Image

When you flash the build image, use your specific board name. The flashing script uses the configuration in the <board>.conf file during the flashing process.

Setting Optional Environment Variables

flash.sh updates the following environment variables based on board EEPROM and other parameters passed. If you want to give specific values to these variables, define them in the board-specific file <board>.conf to override the default values:

# Optional Environment Variables:
# BCTFILE ---------------- Boot control table configuration file to be used.
# BOARDID ---------------- Pass boardid to override EEPROM value
# BOARDREV --------------- Pass board_revision to override EEPROM value
# BOARDSKU --------------- Pass board_sku to override EEPROM value
# BOOTLOADER ------------- Bootloader binary to be flashed
# BOOTPARTLIMIT ---------- GPT data limit. (== Max BCT size + PPT size)
# BOOTPARTSIZE ----------- Total eMMC HW boot partition size.
# CFGFILE ---------------- Partition table configuration file to be used.
# CMDLINE ---------------- Target cmdline. See help for more information.
# DEVSECTSIZE ------------ Device Sector size. (default = 512Byte).
# DTBFILE ---------------- Device Tree file to be used.
# EMMCSIZE --------------- Size of target device eMMC (boot0+boot1+user).
# FLASHAPP --------------- Flash application running in host machine.
# FLASHER ---------------- Flash server running in target machine.
# INITRD ----------------- Initrd image file to be flashed.
# KERNEL_IMAGE ----------- Linux kernel zImage file to be flashed.
# MTS -------------------- MTS file name such as mts_si.
# MTSPREBOOT ------------- MTS preboot file name such as mts_preboot_si.
# NFSARGS ---------------- Static Network assignments; client, server,
#                          & gateway IP addresses & netmask in format:
#                          <c_IP>:<s_IP>:<g_IP>:<netmask>
# NFSROOT ---------------- NFSROOT, an IP address, colon, and path,
#                          e.g. 127.0.0.1:/exported/rootfs_dir.
# ODMDATA ---------------- Odmdata to be used.
# PKCKEY ----------------- RSA key file to use to sign bootloader images.
# ROOTFSSIZE ------------- Linux RootFS size (internal emmc/nand only).
# ROOTFS_DIR ------------- Linux RootFS directory name.
# SBKKEY ----------------- SBK key file to use to encrypt bootloader images.
# SCEFILE ---------------- SCE firmware file such as camera-rtcpu-sce.img.
# SPEFILE ---------------- SPE firmware file path such as bootloader/spe.bin.
# FAB -------------------- Target board's FAB ID.
# TEGRABOOT -------------- lowerlayer bootloader such as nvtboot.bin.
# WB0BOOT ---------------- Warmboot code such as nvtbootwb0.bin

Note

All of the parameters must be added below the reference to the file p3668.conf.common to be reflected in the flashed image.

Here is an example of environment variable settings for the Jetson Xavier NX Developer Kit .conf file, p3509-0000+p3668-0000-qspi-sd.conf:

source "${LDK_DIR}/p3668.conf.common";
BLBlockSize=1048576;
EMMC_CFG=flash_l4t_t194_spi_sd_p3668.xml;
RECROOTFSSIZE=100MiB

To flash the build image

  • Enter the command:

    $ sudo ./flash.sh <board> mmcblk0p1