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FBIOGET_FSCREENINFO

The Atlas 200/300/500 Inference Product does not support this API.

The Atlas Training Series Product does not support this API.

Description

Obtains fixed FB information, including the display buffer address in user mode and display buffer size.

Restrictions

  • Before using the HiFB API, you need to call hi_mpi_vo_enable to enable the VO device.
  • The display buffer obtains the user-mode virtual address using the mmap function of the kernel. Note that the user-mode virtual address cannot be accessed by the accelerator. To set the user-mode address for the accelerator, use the mmio_start parameter in fb_fix_screeninfo.
  • If a graphics layer does not need to be displayed, you need to call the munmap API of the kernel to release the user-mode virtual address. Otherwise, the graphics layer is unavailable and the driver cannot exit.
  • This API does not support multiple processes or multiple threads.

Prototype

int ioctl (int fd, FBIOGET_FSCREENINFO, fb_fix_screeninfo *fix)

Parameters

Parameter

Input/Output

Description

fd

Input

File descriptor of an FB device.

When open("/dev/fbx") is called in the application, the file descriptor of the FB device corresponding to the current VO device is returned.

FBIOGET_FSCREENINFO

Input

ioctl number.

fix

Output

Pointer to the fixed information structure.

Returns

  • 0: success
  • Other values: failure