Module address_space 

Per-process address spaces for Strat9-OS.

Each task owns an AddressSpace backed by a PML4 page table. Kernel tasks share a single kernel address space. User tasks get a fresh PML4 with the kernel half (entries 256..512) cloned from the kernel’s table.

PML4 is the Page Map Level 4, the top-level page table in x86_64’s 4-level paging scheme. It contains 512 entries, each covering a 512 GiB region of the virtual address space. By cloning the kernel half of the PML4, each user address space automatically shares the kernel mappings without needing to duplicate them. Source : https://wiki.osdev.org/Memory_Management

x86_64 virtual address space layout:

• PML4[0..256] => user space (per-process, zeroed for new AS)
• PML4[256..512] => kernel space (shared, cloned from kernel L4)

Structs

AddressSpace

A per-process address space backed by a PML4 page table.

EffectiveMapping

An effective mapping currently installed in the page tables.

VirtualMemoryRegion

A tracked virtual memory region within an address space.

VmaFlags

Flags describing permissions for a virtual memory region.

Enums

VmaPageSize

Supported page sizes for VMAs.

VmaType

Type/purpose of a virtual memory region.

Functions

init_kernel_address_space^⚠

Initialize the kernel address space singleton.

kernel_address_space

Get a reference to the kernel address space.