Module paging 

Virtual Memory Management (Paging) for Strat9-OS

Uses the x86_64 crate’s OffsetPageTable which is designed for the HHDM (Higher Half Direct Map) pattern : exactly what the UEFI bootloader provides.

Provides map/unmap/translate operations on the active page table.

Structs

BuddyFrameAllocator

Wrapper around the buddy allocator implementing the x86_64 crate’s FrameAllocator trait.

Statics

KERNEL_CR3 🔒

Physical address of the kernel’s level-4 page table (set at init, never changes).

KERNEL_PT_LOCK 🔒

Serializes mutations of the canonical kernel page tables.

PAGING_READY 🔒

Paging initialization flag.

Functions

active_page_table

Read the current CR3 value (physical address of the active level-4 page table).

ensure_hhdm_range 🔒

ensure_identity_map

Ensure a physical address is identity-mapped in the HHDM region.

ensure_identity_map_range

Ensure a physical range is mapped in the HHDM region.

init

Initialize the paging subsystem.

is_hhdm_range_mapped_now

Returns whether the current page tables map the HHDM view of the whole range.

is_initialized

Returns whether initialized.

kernel_l4_phys

Return the physical address of the kernel’s level-4 page table.

map_all_ram

Map all RAM regions from the memory map into the HHDM.

map_page

Map a virtual page to a physical frame with the given flags.

map_page_kernel

Map a page into the kernel’s canonical page tables (not the active CR3).

retire_uefi_identity_code^⚠

Revoke the loader’s temporary identity RX pages before starting allocators.

set_trampoline_execution

Change execution of just the existing 4 KiB identity trampoline page, preserving its cache selector. BSP enables it before SIPI and retires it after every AP has left it. APs invalidate their TLB at the boot barrier.

translate

Translate a virtual address to its mapped physical address.

translate_via_active_page_tables 🔒

uncached_hhdm_flags 🔒

unmap_page

Unmap a page from the active CR3, returning the physical frame.

unmap_page_kernel

Unmap a page from the kernel’s canonical page tables.