I mean does it use the CPU to access MMIO to put pixels on the display without having other hardware (e.g. GPU, etc.) follow-up after it.
When Windows 98 boots, it loads an image by whatever program launches (Winload.exe?) and decodes the image and writes to the MMIO device to the display. A GPU is not needed for this, but Windows 98 has device drivers for GPUs. I assume it works like this:
WIN LOADING PROGRAM - > IMAGE DECODING - > CALL DISPLAY DRIVER - > WRITE PIXELS.
Here are the two questions:
1.When Windows 98 boots and shows the flagship, splash-screen image by default (or any user-defined image), does it have the CPU decode it and write it directly to a framebuffer/VGA/VESA software middleware (driver) to put the pixels on the display and avoid using the GPU if a GPU driver loaded?
2.If no GPU driver is detected, can Windows 98 run completely fine (the OS itself) without any GPU and just have the CPU write to the framebuffer (not considering stuff like OpenGL/DirectX/etc.)?
In simpler words, does Windows 98 operate 100% with the CPU and needs no GPU (except for maybe OpenGL/DirectX high-end graphics manipulation/hardware accelerated drawing/etc. for games, video decoding, etc.)? 3-D games probably use GPU rapid graphics accelerating with OpenGL/DirectX, so it's unlikely the CPU does anything but write to the GPU for this. But the shell/GUI and basic functions of the OS seem to be very basic and lacking any acceleration, and possibly just are drawn with the CPU alone using some sort of display drawing low-level software for pixel manipulation?
Note that I am saying "GPU", but we can consider that to mean any non-CPU hardware that writes to the display. CPUs can write directly to the display without any GPU, but going further than this entails MMIO, low-level programming, specifications, and electronic/computer engineering.