[LavenderDay3544]

OP here.

The plan is to hand out panes which are just memory buffers to which applications write pixel data as they would on a framebuffer then when the kernel goes to actually refresh the display it composites any visible panes onto the back buffer and then swaps buffers. There is nothing unsafe about that any more so than any other use of shared memory regions between the kernel and userspace and those are quite prolific in existing popular OSes.

If anything the Unix display server nonsense is overly convoluted and far worse security wise.

[idle_zealot]

Does this mean that window management has to be handled in the kernel? Or is there some process that tells the kernel where those panes should be relative to one another/the framebuffer?

[LavenderDay3544]

That's going to tentatively be handled in kernel unless there good reason to do otherwise. The idea is to expose low level hardware interfaces across the board and this seemed to be the best way to multiplex actual hardware framebuffers while still keeping things low level.

From there each application can draw its own GUI and respond to events that happen in its panes like a mouse button down event while the cursor is at some coordinates and so forth using event capabilities. What any event or the contents of a pane mean to the application doesn't matter to the OS and the application has full control over all of its resources and its execution environment with the exception of not being allowed to do anything that could harm any other part of the system outside its own process abstraction. That's my rationale for why the display system and input events should work that way. Plus it helps latency to keep all of that in the kernel especially since we're doing all the rendering on the CPU and are thus bottlenecked by the CPU's memory bus having way lower throughput compared to that of a discrete GPU. But that's the way it has to be since there are basically no GPUs out there with full publicly available hardware documentation as far as I know and believe me I've looked far and wide and asked around. Eventually I'll want to port Mesa because redoing all the work develop something that complex and huge just isn't pragmatic.