12 Replies Latest reply on Feb 26, 2014 7:31 AM by LynnZ

    Timing settings for graphics mode in D2550

    vishnuvardhanavula Green Belt



      The D2550 processor hangs when run in Linux frame buffer mode. After the graphics background has been drawn it freezes. It does not happen with N2600. There is no software difference between the two and they used the same VGA BIOS. The only difference is the graphics core speed of 640 MHz for D2550/N2800 and 400 MHz for N2600. That means that the D2500/N2800 needs different settings than N2600. The problem is that the VGA BIOS does not seem to know the difference between the CPUs and therefore sets the wrong timings which cause them to hang. The VGA BIOS therefore depends on the system BIOS to either setup the core frequency or tell the VGA BIOS the core frequency by initializing some registers.


      How should the system BIOS interact with the VGA BIOS to help it to use the proper timings for the graphics modes?


      How can the HDMI interface on Cedarview/NM10 be enabled via the BIOS?


      Leads on the above issues will be very helpful. Thank you!


      Best regards,