DXGKDDI_EXCHANGEPRESTARTINFO callback function (dispmprt.h)

Artikel
02/22/2024

Allows very simple data to be exchanged between the OS and driver which may be required prior to DxgkDdiStartDevice device being called and therefore cannot be queried through normal caps or adapter info DDIs.

Syntax

DXGKDDI_EXCHANGEPRESTARTINFO DxgkddiExchangeprestartinfo;

NTSTATUS DxgkddiExchangeprestartinfo(
  [in] IN_CONST_HANDLE hAdapter,
  [in] IN_OUT_PDXGK_PRE_START_INFO pPreStartInfo
)
{...}

Parameters

[in] hAdapter

Identifies the adapter.

[in] pPreStartInfo

Pointer to a DXGK_PRE_START_INFO structure, which contains both fields for the OS to pass info and fields for the driver to return info. Initially, only SupportPreserveBootDisplay is defined.

[out] SupportPreserveBootDisplay

The driver and hardware support the requirements that allow the boot frame buffer to be used and displayed throughout the hardware initialization, performed during DxgkDdiStartDevice.

Return value

If this routine succeeds and returns the requested change, it returns STATUS_SUCCESS.

Remarks

This DDI will be called after DxgkDdiAddDevice and before DxgkDdiStartDevice so that the driver does not have access to its own hardware resources. However, it can use the PhysicalDeviceObject passed to the driver in DxgkDdiAddDevice to call IoGetDeviceProperty. For example, it can find the hardware id in order to decide what to return in the output fields of the DXGK_PRE_START_INFO structure.

This function is always called at PASSIVE level so the supporting code should be made pageable where possible.

Requirements

Requirement	Value
Target Platform	Windows
Header	dispmprt.h

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