# Boot device tree

The boot device tree properties explain how to enable and disable user-initiated emergency download (EDL) in XBL. They also detail the EDL timeout and the USB cable options that can force the system into EDL mode. You can use these properties to configure boot-related functionality.

The boot DT file path on the Linux build machine is `/boot_images/boot/Settings/Soc/<chipset>/Core/Boot/sw_boot.dtsi.`

| Property name | Property description | Data type | Possible values/value range | Device behavior |
| --- | --- | --- | --- | --- |
| `vibration` | Turn on/off vibration at XBL exit. | UINT32 | <ul class="simple"><br><li><p>0x00</p></li><br><li><p>0x01</p></li><br></ul> | <ul class="simple"><br><li><p>ENABLE (0x01): Turns on the vibration. 0x01 is the default setting.</p></li><br><li><p>DISABLE (0x00): Turns off the vibration.</p></li><br></ul> |
| <br>`forced_download.feature` | <ul class="simple"><br><li><p>Enable or disable the force emergency download mode (EDL) feature at the XBL stage.</p></li><br><li><p>Flash images using USB cable along with key combination (Press POWER (PWR), VOL+ and VOL-keys together)</p></li><br></ul> | <br>UINT32 | 0x00 | Force EDL feature (FEDL) DISABLE (0x00): FEDL is disabled. |
| <br>`forced_download.feature` | <ul class="simple"><br><li><p>Enable or disable the force emergency download mode (EDL) feature at the XBL stage.</p></li><br><li><p>Flash images using USB cable along with key combination (Press POWER (PWR), VOL+ and VOL-keys together)</p></li><br></ul> | <br>UINT32 | 0x01 | ENABLE (0x01): Enable user-initiated EDL in XBL. |
| <br>`forced_download.check_usb_option` | <br>To enter FEDL mode, select the USB cable options | <br>UINT32 | 0x00 | CHECK\_USB\_D\_PLUS\_GROUND (0x00): The device enters EDL mode when it is powered on using a special USB cable that grounds the D+ line. This is the default setting. |
| <br>`forced_download.check_usb_option` | <br>To enter FEDL mode, select the USB cable options | <br>UINT32 | 0x01 | CHECK\_USB\_D\_PLUS\_HIGH\_WITH\_TIMEOUT (0x01): Connect the device to USB + ground during boot. Device is forced into EDL mode if the connection is removed withing the boot timeout. |
| <br>`forced_download.check_usb_option` | <br>To enter FEDL mode, select the USB cable options | <br>UINT32 | 0x02 | <ul class="simple"><br><li><p>Time out is provided by the <code class="docutils literal notranslate"><span class="pre">forced_download.check_dp_timeout</span></code> DT property in milliseconds (ms)</p></li><br><li><p>CHECK_USB_REGULAR_CABLE (0x02): The device is forced to EDL when booting with a normal USB cable.</p></li><br></ul> |
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## UEFI

> 
> 
> In the UEFI environment, the device path protocol defines how to connect and identify the devices, with nodes being part of this protocol.
> The UEFI file path on the Linux build machine is `/boot_ images/boot/Settings/Soc/Core/Uefi/cfg/ueficfg.dtsi`.
> 
> 
> The following table lists the main types of UEFI device path nodes and property names.

Table: UEFI device path nodes and properties

| DT property name | Data type | Possible values/value range | Description |
| --- | --- | --- | --- |
| OsConfigTableSelection | UINT32 | Range is from 0x1 to 0x2 depending on the Hypervisor. | You can specify which Hypervisor to use. The values are as follows:<br><br><br><br>> <br>> <br>> <ul class="simple"><br>> <li><p>0x1 - BOOT_TYPE_LINUX - Gunyah <sup>TM</sup> Hypervisor Software</p></li><br>> <li><p>0x2 - BOOT_TYPE_LINUX_WITH_KVM</p></li><br>> </ul> |
| QcCapsuleRootCert | UINT8 list | Has the OpenSSL generated certificate content. | You use the root certificate for capsule authentication. This node has the entire root certificate content, which you use to authenticate the capsule. You also use this node for firmware updates. |

Last Published: Apr 30, 2025

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