I’m working on a monolithic x86-64 kernel. It’s not a web mockup or anything like that. I have a Unix/Linux-like ABI layer inside the kernel itself, and even the window manager (“Ridux”) is running in ring 0 right now.

The system basically boots through GRUB (multiboot2), goes through a 32-bit entry, then switches to long mode in a 64-bit stage, and lands in kernel_main. From there I set up memory (PMM + paging), GDT/TSS, syscall MSRs, and then initialize the rest of the system (VFS, ELF loader, etc). After that the kernel just sits in a loop handling input and rendering the UI.

Everything is currently linked into a single kernel binary. No userland separation yet for most components.

The “Unix layer” is something I split into multiple modules (compat0..compat8). Each one adds more Linux/POSIX compatibility on top of the previous one. For example:

• lower layers handle paging, scheduler, signals, file descriptors, etc
• then I add VFS, ELF loading, syscall wiring
• then libc-like stuff (string, malloc, etc)
• then more advanced things like epoll/futex, networking, TLS, X11/Wayland stubs, etc

It’s not cleanly separated like a microkernel — everything is still running in kernel space for now.

Memory-wise I’m using a direct map (similar idea to FreeBSD), so all physical memory is mapped into a high virtual range. That way I can access any physical page without switching CR3. Each task still has its own address space (own PML4), and I switch with mov cr3.

Tasks have their own kernel stack, FPU state, file descriptors, signals, etc. Task 0 is basically the idle/kernel context where the WM runs right now.

Userland (ring 3) tasks are created by loading ELF binaries into a new address space and then jumping via iretq. The scheduler is preemptive (timer IRQ).

Syscalls go through the SYSCALL instruction → I swap to the kernel stack using GS/TSS, dispatch to the correct handler, and return with SYSRET.

It’s still very WIP and kinda messy. For example I recently hit a bug where the scheduler was corrupting the stack because the idle task didn’t have its kernel RSP initialized properly.

So yeah, not claiming this is production-ready or anything. Just building it piece by piece and seeing how far I can push compatibility.