Partition Configuration¶

NVIDIA^® Jetson™ Linux supports formatting mass storage media into multiple partitions for storing data, such as the device OS image, bootloader image, device firmware, and bootloader splash screen.

How Jetson Partition Configurations Are Described¶

Some Jetson platforms have similar characteristics, such as identical partition configurations. This topic groups these platforms and provides information about each group. The supported platforms are grouped in the following way:

Group

Includes platforms

NVIDIA^®

Jetson AGX Orin™ series

Jetson AGX Orin (P3701-0000)

NVIDIA^® Jetson Xavier™ NX series

Jetson Xavier NX (P3668-0000, for development only)
Jetson Xavier NX (P3668-0001, 8 GB RAM)
Jetson Xavier NX 16GB (P3668-0003, 16 GB RAM)

NVIDIA^® Jetson AGX Xavier™ series

Jetson AGX Xavier (P2888-0001, 16 GB RAM)
Jetson AGX Xavier (P2888-0004, 32 GB RAM)
Jetson AGX Xavier 64GB (P2888-0005, 64 GB RAM)
Jetson AGX Xavier Industrial (P2888-0008, 32 GB RAM)

Partition Configuration Files¶

A partition configuration file describes the mass storage devices and partitions on a platform.

The following table describes the definitions of all of the partition configurations supported by Jetson Linux. The File column specifies the filename of the partition configuration file the defines the configuration, and the Device columns specify the <device> block in that file that defines the configuration (refer to <device> Element Tag Attributes for more information).

Platform & Configuration	Boot Partition Device	User Partition Device	File
Jetson AGX Orin Developer-Kit	QSPI_NOR	sdmmc_boot on 32GB eMMC	flash_l4t_t234_qspi_sdmmc.xml
Jetson AGX Xavier Developer-Kit	sdmmc_user on 32GB eMMC	sdmmc_user on 32GB eMMC	flash_l4t_t194_sdmmc.xml
Jetson AGX Xavier NX Developer-Kit	QSPI_NOR	SD card	flash_t194_spi_sd_p3668.xml (flash_l4t_t194_qspi_p3668.xml for flashing QSPI_NOR only)
Commercial Modules: Jetson Xavier NX (P3668-0001) Jetson Xavier NX 16GB DRAM (P3668-0003)	QSPI_NOR	sdmmc_user on 16GB eMMC	flash_l4t_t194_spi_emmc_p3668.xml
Commercial Modules: Jetson AGX Xavier (P2888-0001 and P2888-0004) Jetson AGX Xavier 64GB DRAM (P3668-0005)	sdmmc_boot on 32GB eMMC	sdmmc_user on 32GB eMMC	flash_l4t_t194_sdmmc.xml
Commercial Modules: Jetson AGX Xavier Industrial (P2888-0008)	QSPI_NOR	sdmmc_user on 32GB eMMC	flash_l4t_t194_spi_emmc_jaxi.xml

Each file’s name typically incorporates its processor name (t194 or t234), the type of memory the partitions are flashed to (sd for SD Card, spi for SPI, or emmc for eMMC), and in some cases, the module’s part number, for example, p3668).

During the flashing procedure, flash.sh:

Reads the partition configuration file <device>.xml
Translates keywords into values specified in <device>.conf or in command line options
Saves the translated data in bootloader/flash.xml

bootloader/tegraflash.py reads in bootloader/flash.xml and flashes the device that was specified by bootloader/flash.xml.

Refer to List of Translated Keywords for more information.

Format of a Partition Configuration File¶

Each partition configuration file defines one or more partition layouts for a specific configuration of a specific Jetson device. The file is composed of the following XML elements:

A standard XML prolog.
One or more <partition_layout> elements, each of which defines one partition layout.
In each <partition_layout> element, a <device> element for each device, for example, each type of flashed memory, that the layout uses.
In each <device> element, a <partition> element for each partition in that device’s partition layout.
In each <partition> element, a group of other elements that specify various properties of the partition.

<partition_layout> Element¶

The <partition_layout> element has the following syntax:

<partition_layout version="01.00.0000">
    <!-- Device elements go here. -->
</partition>

<device> Element¶

The partition configuration file contains a device element for each subdevice; for example, for the eMMC boot and user hardware partitions. This element must be present even if the devices are not divided into subdevices.

The <device> element has the following syntax:

<device type="<device type>" instance="<instance>">
    <!-- Partition elements go here. -->
</device>

<device> Element Tag Attributes¶

The following table describes the <device> tag’s attributes and their legal values.

Device attributes	Values	Description
device type	`sdmmc_boot`; `sdmmc_user SPI`; `nvme`	Required. Specifies the type of device. eMMC `boot0` and `boot1` hardware partitions are treated as a single `sdmmc_boot` entry.
instance	0-3	Required. Specifies the device instance: 0 for SPI or NVMe, or 3 (typically) for eMMC.

<partition> Element¶

Each <partition> element has the following syntax:

<partition name="<name>" type="<type>" oem_sign="true ">
    <!-- partition properties go here -->
</partition>

<partition> Element Tag Attributes¶

This table describes the attributes supported for partition elements and their legal values.

Device attributes	Values
name	See the files listed in the table of partition configuration files.	Required. Specifies a name for the partition. The name can have a maximum of 36 characters. There are three kinds of partitions: mandatory, optional, and user-defined. All mandatory and optional partition names must be associated with the specific partition type. All user-defined partition names must be associated with partition type data.
type	See the files listed in the table of partition configuration files.	Required. Specifies the type of partition. Certain partition types are valid only when they are associated with specific partition names.
oem_sign	`True`, `False`, or unspecified.	Jetson AGX Xavier series only: If `True`, append a generic signature header to the binary and perform OEM signing on it. If `False`, append a NULL signature header to the binary and perform NULL signing on it.

<partition> Child Elements¶

The following tags specify the properties of a <partition> element:

Tag	Values	Description
<allocation_policy>	sequential	Specifies the type of allocation policy. Sequential partitions begin immediately after the preceding partition.
<filesystem_type>	basic	The `filesystem_type` value `basic` specifies a “raw” partition. (The legacy “ext2” file system has been deprecated.)
<size>	<partition_size>	Required. Specifies the size of the partition in bytes. May be a decimal number or a hexadecimal number of up to 16 digits. The partition size may be equal to or greater than the size of the file to be written to the partition. Specifying a greater size allows you to increase the file size later without changing the partition configuration file. If the partition size is less than an erase block size, it aligns itself to the partition erase block boundary. The `size` property of the secondary GPT partition, which is defined at the end of each device, must always be `0xffffffffffffffff`. TegraFlash calculates this partition's size automatically; the preceding partition is extended to fill any free space before the secondary GPT.
<file_system_attribute>	0	Not implemented.
<allocation_attribute>		`0x008` or `0x808`. Must be `0x808` for the partition immediately preceding the secondary GPT.
<percent_reserved>	0	Reserved for future use.
<filename>	`<filename>` or empty	Specifies the name of the file to write into the partition. If the filename is empty, no data is written to the partition.

List of Translated Keywords¶

The following table provides keywords that you can use as the text for some <partition> child elements. When the partition configuration file processor encounters one of these keywords, it substitutes the value shown or described in the table.

Keyword	Default translated value in `flash.xml`
MB1FILE	`mb1_t194_prod.bin`
SPEFILE	`spe_t194.bin`
TEGRABOOT	`nvtboot_t194.bin`
MTSPREBOOT	`preboot_c10_prod_cr.bin`
APPSIZE	30064771072
APPFILE	`system.img`
MTS_MCE	`mce_c10_prod_cr.bin`
MTSPROPER	`mts_c10_prod_cr.bin`
TBCFILE	`uefi_jetson.bin`
TBCDTB-FILE	Appropriate bootloader DTB file name
TOSFILE	`tos_t194.img`
EKSFILE	`eks.img`
BPFFILE	`bpmp_t194.bin`
BPFDTB-FILE	Appropriate BPMP DTB file name
CAMERAFW	`camera-rtcpu-rce.bin`
WBOBOOT	`warmboot_t194_prod.bin`
LNXSIZE	67108864
LNXFILE	`boot.img`
DTB_FILE	Appropriate kernel DTB file name
RECFILE	Name of appropriate recovery kernel image
RECDTB-FILE	Name of appropriate recovery kernel dtb file
BOOTCTRL-FILE	`kernel_bootctrl.bin`

External Storage Device Partition¶

To create a partition configuration file for flashing to an external storage device, start with a default SD card partition table as a template (for example, the Jetson Xavier NX development module SD Card partition from the table of partition configuration files). Change the device type to nvme, and the instance number to zero, as in the example below. An external partition configuration file must contain at least three partitions: master_boot_record, primary_gpt, and secondary_gpt.

For both SCSI devices (e.g. SCSI flash drives and hard disk drives) and NVMe devices, for example NVMe SSDs, the device type is nvme. You must also update num_sectors to correctly specify the total amount of storage available on your external device. For example, if an NVMe device has 1024209543168 bytes available, you must change num_sectors to 1024209543168/512 = 2000409264 sectors.

<partition_layout version="01.00.0000">
  <device type="nvme" instance="0" sector_size="512" num_sectors="61071360">
    <partition name="master_boot_record" type="protective_master_boot_record">
      <allocation_policy> sequential </allocation_policy>
      <filesystem_type> basic </filesystem_type>
      <size> 512 </size>
      <file_system_attribute> 0 </file_system_attribute>
      <allocation_attribute> 8 </allocation_attribute>
      <percent_reserved> 0 </percent_reserved>
      <description> **Required.** Contains protective MBR. </description>
    </partition>
    <partition name="primary_gpt" type="primary_gpt">
      <allocation_policy> sequential </allocation_policy>
      <filesystem_type> basic </filesystem_type>
      <size> PPTSIZE </size>
      <file_system_attribute> 0 </file_system_attribute>
      <allocation_attribute> 8 </allocation_attribute>
      <percent_reserved> 0 </percent_reserved>
      <description> **Required.** Contains primary GPT of the `sdmmc_user` device. All
        partitions defined after this entry are configured in the kernel, and are
        accessible by standard partition tools such as gdisk and parted. </description>
    </partition>
    <partition name="secondary_gpt" type="secondary_gpt">
      <allocation_policy> sequential </allocation_policy>
      <filesystem_type> basic </filesystem_type>
      <size> 0xFFFFFFFFFFFFFFFF </size>
      <file_system_attribute> 0 </file_system_attribute>
      <allocation_attribute> 8 </allocation_attribute>
      <percent_reserved> 0 </percent_reserved>
      <description> **Required.** Contains secondary GPT of the `sdmmc_user`
        device. </description>
    </partition>
  </device>
</partition_layout>