I was searching for a syscall that would draw a pixel on a given coordinate on the screen on something similar. But I couldn't find any such syscalls in this site.

I came to know that OS interacts with monitors using graphic drivers. But these drivers may be different on different machines. So is there a common native API provided by linux for handling these?

Much like how there are syscalls for opening, closing, reading, writing to files. Even though underlying file systems maybe different, these syscalls provide an abstract API for user programs to simplify things. I was searching something similar for drawing onto the screen.

CodePudding user response：

Typically a user is running a display server and window system which organizes the screen into windows which applications draw to individually using the API provided by that system. The details will depend on the architecture of this system.

The traditional window system on Linux is the X window system and the more modern Wayland display server/protocol is also in common use. For example X has commands to instruct the X server to draw primitives to the screen.

If no such system is in use, you can directly draw to a display either via a framebuffer device or using the DRM API. Both are not accessed by special syscalls, but instead by using normal file syscalls like open, read, write, etc., but also ioctl, on special device files in /dev, e.g. /dev/dri/card0 for DRM to the first graphics card or /dev/fb0 for the first framebuffer device. DRM is also used for applications to render directly to the screen or a buffer when under a display server or window system as above.

In any case DRM is usually not used directly to draw e.g. pixels to the screen. It still is specific to the graphics card. Typically a library like Mesa3D is used to translate the specific details into a common API like OpenGL or Vulkan for applications to use.