In the good old days when graphics parameters were configured explicitly
  in a file called xorg.conf, even broken hardware could be managed.
  
  Today, with the advent of Kernel Mode Setting, a graphics board is
  either correctly working because all components follow the standards -
  or the computer is unusable, because the screen remains dark after
  booting or it displays the wrong area. Cases when this happens are:
  - The graphics board does not recognize the monitor.
  - The graphics board is unable to detect any EDID data.
  - The graphics board incorrectly forwards EDID data to the driver.
  - The monitor sends no or bogus EDID data.
  - A KVM sends its own EDID data instead of querying the connected monitor.
  Adding the kernel parameter "nomodeset" helps in most cases, but causes
  restrictions later on.
  
  As a remedy for such situations, the kernel configuration item
  CONFIG_DRM_LOAD_EDID_FIRMWARE was introduced. It allows to provide an
  individually prepared or corrected EDID data set in the /lib/firmware
  directory from where it is loaded via the firmware interface. The code
  (see drivers/gpu/drm/drm_edid_load.c) contains built-in data sets for

  commonly used screen resolutions (800x600, 1024x768, 1280x1024, 1600x1200,

  1680x1050, 1920x1080) as binary blobs, but the kernel source tree does
  not contain code to create these data. In order to elucidate the origin
  of the built-in binary EDID blobs and to facilitate the creation of
  individual data for a specific misbehaving monitor, commented sources
  and a Makefile environment are given here.

  
  To create binary EDID and C source code files from the existing data
  material, simply type "make".

  If you want to create your own EDID file, copy the file 1024x768.S,
  replace the settings with your own data and add a new target to the
  Makefile. Please note that the EDID data structure expects the timing
  values in a different way as compared to the standard X11 format.
  
  X11:
  HTimings:  hdisp hsyncstart hsyncend htotal
  VTimings:  vdisp vsyncstart vsyncend vtotal
  
  EDID:
  #define XPIX hdisp
  #define XBLANK htotal-hdisp
  #define XOFFSET hsyncstart-hdisp
  #define XPULSE hsyncend-hsyncstart
  
  #define YPIX vdisp
  #define YBLANK vtotal-vdisp
  #define YOFFSET (63+(vsyncstart-vdisp))
  #define YPULSE (63+(vsyncend-vsyncstart))
  
  The CRC value in the last line

    #define CRC 0x55

  also is a bit tricky. After a first version of the binary data set is
  created, it must be checked with the "edid-decode" utility which will

  most probably complain about a wrong CRC. Fortunately, the utility also
  displays the correct CRC which must then be inserted into the source
  file. After the make procedure is repeated, the EDID data set is ready
  to be used.