Configuring Screen

You configure libraries, drivers, and Screen parameters using the configuration file, graphics.conf.

The graphics.conf file is located in the following directory:

where processor is the CPU architecture of your target hardware (e.g. armle-v7), and platform is the name of your platform (e.g., imx6x).

Unless your target system allows for it, you modify the graphics.conf file on your host, and then build it into your OS image filesystem. When Screen services starts on your target system, it will process the configuration file.

The graphics.conf file is a free-form ASCII text file. Screen or clients parse this file. The file can contain extra tabs and blank lines for formatting purposes. Keywords in the file are case-sensitive. You can place comments anywhere within the file (except within quotes). Comments begin with the # character and end at the end of the line.

The file is a set of configurable parameters, along with the values that these parameters are being set to. You configure these parameters within specific defined sections of the configuration file.

The graphics.conf file includes the following main sections:
khronos

Specifies the libraries and parameters related to Khronos (GPU and WFD libraries). The libraries and parameters in this section apply to your EGL display and WFD driver. This section is denoted by the begin khronos and end khronos statements.

The khronos section can have the following subsections:
  • egl display
  • wfd device
winmgr
Specifies the parameters related to Screen. This section is denoted by the begin winmgr and end winmgr statements. The parameters in this section include those that apply to:
  • Screen globally
  • displays
  • classes (e.g., framebuffers)
The winmgr section can have the following subsections:
  • globals
  • display
  • class

Use the following format to configure the parameter within the appropriate section of the configuration file:

parameter = value

Each configuration parameter must be on its own separate line. If the parameter allows for multiple values as its configuration, then the values follow the = after the parameter and are separated by either a space or a comma. For example:

parmeter = value1,value2,value3

or

parmeter = value1 value2 value3

A typical graphics.conf file will look something like this:
begin khronos
  begin egl display 1
    egl-dlls = [IMG%s] libusc.so libsrv_um.so libpvr2d.so libIMGegl.so
    glesv1-dlls = libusc.so libsrv_um.so  libIMGegl.so libImgGLESv1_CM.so
    glesv2-dlls = libusc.so libsrv_um.so libusc.so libIMGegl.so libImgGLESv2.so
    gpu-dlls = libsrv_um.so libpvr2d.so pvrsrv.so
    gpu-string = SGX540rev120
    aperture = 200
  end egl display

  begin wfd device 1
    wfd-dlls = libomap4modes-panda.so libWFDomap4430.so
  end wfd device
end khronos

begin winmgr
  begin globals
    blit-config = pvr2d
    blits-logsize = 4096
    input-logsize = 8192
    requests-logsize = 65536
  end globals

  begin display hdmi
    formats = rgba8888 rgbx8888 nv12
    video-mode = 1280 x 720 @ 60
  end display

  begin class framebuffer
    display = hdmi 
    pipeline = 3 
    surface-size = 1280 x 720
    format = rgba8888
    usage = pvr2d 
  end class
  

end winmgr