friedrichosdev/nanoos

How friedrichosdev/nanoos works

NanoOS is an experimental x86_64 hobby operating system. Its principal workflow begins with Multiboot2 boot information, initializes kernel CPU and memory facilities, discovers platform hardware, and starts scheduling across available CPUs. Separate branches provide input and graphical output. The README documents the boot sequence and capabilities; source excerpts confirm selected implementation links, but many listed subsystems were not sampled, so their internal connections are not inferred.

Main entry points: init.c Kernel Initialization · apic.c APIC and Timers · smp.c SMP Startup · acpi.c ACPI

Components 24

Boot and Core

Multiboot2 src/kernel/arch/x86_64/boot/multiboot2.c
Kernel Initialization src/kernel/core/init.c
GDT src/kernel/arch/x86_64/gdt/gdt.c
Interrupt Handling src/kernel/arch/x86_64/idt/handler.c

Memory Management

Physical Memory src/kernel/arch/x86_64/mm/pmm.c
Virtual Memory src/kernel/arch/x86_64/mm/vmm.c
Kernel Heap src/kernel/arch/x86_64/mm/heap.c

Platform Hardware

ACPI src/kernel/arch/x86_64/acpi/acpi.c
APIC and Timers src/kernel/arch/x86_64/apic/apic.c
PCI Enumeration src/kernel/arch/x86_64/drivers/pci.c
RTC src/kernel/arch/x86_64/drivers/rtc.c
Serial Driver src/kernel/arch/x86_64/drivers/serial.c

Multitasking

Scheduler src/kernel/sched/sched.c
Threads and Processes src/kernel/sched/thread.c
SMP Startup src/kernel/arch/x86_64/smp/smp.c

Input and Graphics

PS/2 Controller src/kernel/drivers/hid/ps2/i8042.c
Input Events src/kernel/drivers/hid/input.c
HID Interface src/kernel/drivers/hid/hid.c
Framebuffer Driver src/kernel/drivers/gfx/framebuffer/fb_driver.c
Graphics Abstraction src/kernel/drivers/gfx/gfx.c
2D Compositor src/kernel/drivers/gfx/compositor/compositor.c
Version Splash src/kernel/drivers/gfx/version_splash/version_splash.c

Kernel Runtime

Math Library src/kernel/lib/math/__rem_pio2_large.c

Other components

UEFI / GRUB

Connections 24

UEFI / GRUB → Multiboot2: loads kernel README.md
Multiboot2 → Kernel Initialization: passes boot data README.md
Kernel Initialization → GDT: initializes CPU README.md
Kernel Initialization → Interrupt Handling: initializes interrupts README.md
Kernel Initialization → Physical Memory: initializes memory README.md
Kernel Initialization → Virtual Memory: initializes memory README.md
Virtual Memory → Physical Memory: allocates pages src/kernel/arch/x86_64/mm/vmm.c
Kernel Initialization → ACPI: initializes platform README.md
Kernel Initialization → APIC and Timers: initializes platform README.md
Kernel Initialization → PCI Enumeration: initializes platform README.md
APIC and Timers → ACPI: reads tables src/kernel/arch/x86_64/apic/apic.c
PCI Enumeration → ACPI: reads tables src/kernel/arch/x86_64/drivers/pci.c
Kernel Initialization → Scheduler: starts scheduling README.md
Kernel Initialization → SMP Startup: starts SMP README.md
SMP Startup → APIC and Timers: starts CPUs src/kernel/arch/x86_64/smp/smp.c
SMP Startup → GDT: loads descriptors src/kernel/arch/x86_64/smp/smp.c
Interrupt Handling → APIC and Timers: acknowledges IRQ src/kernel/arch/x86_64/idt/handler.c
Kernel Initialization → PS/2 Controller: initializes input README.md
PS/2 Controller → Input Events: delivers events
Input Events → HID Interface: provides events
Kernel Initialization → Framebuffer Driver: initializes graphics README.md
Framebuffer Driver → Graphics Abstraction: provides video
Graphics Abstraction → 2D Compositor: renders layers
2D Compositor → Version Splash: renders splash

Drawn by GitDiagram on November 11, 2026 from the repository's file tree, README and source files. Read as Markdown ·