I am working on a extend graphic driver for MacOS, and use IOFrameBuffer class to publish a linear frame buffer device. In my driver we use getVRAMRange() to return the video ram address information for the entire memory window of frame buffer device.
The question is: The driver can works well on MacOS 10.12, but once upgrading system to MacOS 10.13 High Sierra, I can't access video ram data any more. Do you have any tips on this issue? Thanks very much!
besides, I am also confused why the driver can works well with safe mode?
This is an old issue, Apple deprecated IOFramebuffer class. we can access screen steam buffer through IOSurfaceRef, and use IOSurfaceGetBaseAddress function get screen data address.