Module phys_mapper 

HHDM-based PhysMapper for Kernel Virtual Memory

This module provides a PhysMapper implementation for kernels that use a higher-half direct map (HHDM). It allows safe and portable access to physical memory by converting a physical address to a usable pointer in the current virtual address space.

Why is this needed?

• Rust and C code can only dereference virtual addresses, not physical ones.
• When manipulating page tables or other physical memory, you need a way to “see” or “touch” a physical address from your code.
• The mapping strategy (HHDM, identity, temporary) may differ between bootloader, kernel, and tests, so this trait abstracts over those details.

How does it work?

• With HHDM, every physical address is mapped at HHDM_BASE + pa.
• This implementation simply adds the HHDM base to the physical address and returns a pointer.

Example

use kernel_vmem::{addresses::PhysicalAddress, page_table::pt::PageTable, PhysMapper};
use kernel_alloc::phys_mapper::HhdmPhysMapper;
let phys = PhysicalAddress::new(0x1234_0000);
let mapper = HhdmPhysMapper;
unsafe {
    let table: &mut PageTable = mapper.phys_to_mut(phys);
}

See also

• PhysMapper trait in kernel-vmem
• Your kernel’s memory layout and HHDM configuration

Structs

HhdmPhysMapper

PhysMapper implementation for kernels with a higher-half direct map (HHDM).