root@arm:~# cd /sys/class/drm/card0/card0-HDMI-A-1
root@arm:/sys/class/drm/card0/card0-HDMI-A-1# parse-edid edid
^C
root@arm:/sys/class/drm/card0/card0-HDMI-A-1# cat edid
▒▒▒▒▒▒A
▒▒▒▒,x*▒VQ▒'
PT▒K▒▒▒▒▒0*@▒`▒d0P▒▒▒UK01303059530▒Philips 206V4▒8LS
      Jroot@arm:/sys/class/drm/card0/card0-HDMI-A-1# ls
device  dpms  edid  enabled  modes  power  status  subsystem  uevent
root@arm:/sys/class/drm/card0/card0-HDMI-A-1# cat modes
1280x1024
1280x720
1024x768
1024x768
800x600
800x600
640x480
640x480
640x480
640x480
720x400
root@arm:/sys/class/drm/card0/card0-HDMI-A-1#
root@arm:/sys/class/drm/card0/card0-HDMI-A-1# xrandr -display :0.0 -q
Can't open display :0.0
root@arm:/sys/class/drm/card0/card0-HDMI-A-1# xrandr -display :0.0 --output HDMI-0 --mode 1024x768 --rate 60
Can't open display :0.0