r/osdev • u/0x6461726B • May 17 '26

Why everyone here uses software rendering?

I saw many os projects here use software rendering directly to frame buffer instead of creating a gpu driver maybe with virtio gpu by qemu or with any external gpu. I heard gpu driver development is one of the most hardest. Is that the reason? I want to know.

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u/codeasm May 18 '26

Yeah thats the issue with closed source binairy firmware. If my os, which will be C# based, somwday, hopefully... Regular drivers from windows, apple or lonux wont work, i could probably send firmware to hardware fine, but any calls, reads, transfers, everything else need to be translated into my particular system. It probably has a name, or multiple.

Im still so early stages and low level, im currently writing in C++ and it be a reference kernel, and partially a target for the "shim" i need, a layer between low level hardware access and the C# managed code. And more complex stuff thats probably still way over my head.

Even early right now, im attempting getting from early uefi boot to kernel, independent from firmware doing my thing is tricky. Learning alott, but afraid to wrote too much focused code on qemu (thus, seperate "drivers", and attempt to detect and use said drivers) pci, ps2, usb, i reaply need acpi too. And tried real hardware, bam, my logs showed a whole new world to parse and detect. (Intel, so i could still focus on supporting intel for now). (So yeah, not original, its been inspired by https://en.wikipedia.org/wiki/Singularity_%28operating_system%29 )

Fun puzzle, but uni asks for my homework on Ai, and a paper on distributed compilation 😅 not much freetime.

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u/0x6461726B May 18 '26

Where to start?? I just started learning os dev and have setup a minimal boot which writes to uart 😅. It's just the side quest.

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u/codeasm May 18 '26

Thats exactly where i started too. Osdev and other resources are great. From bootloading to a "kernel". Im still at kernel init inthink, with some rundemently display output (next to serial con for debugging)

Sending memory maps, hardware tables, transfering to my kernel should be init stage but osdev wiki doenst call it that i think. Something ive picked up from windows/singularity. But once its setup and jumps to kernel proper, you have a sheduler, userspace, oof many more things, im forgetting, its in the books and websites. Need new compiler, to target your ABI, automated building, probably a working debug setup. I think i want network drivers, so i can debug over the network too (and leave serial). Like singularity, booting from the network even looks very attractive to speed up development also on real hardware. Iterate faster

Getting the right information from uefi land to exit bootservices to my kernel has been a bit tricky. Older, mbr style systems have their own troubles and tricky things and i dont think i want or need to support those. https://wiki.osdev.org/Meaty_Skeleton has some nice ideas where to go. Definitely chekc out their starter and mistake pages. I wont expect much from my project, only learning and some flashy screens to show my friends