Struct PageFrameManager 

pub struct PageFrameManager;

The page frame manager singleton.

This type implements AbsPageFrameManager and is the central point for manipulating page frame flags and accessing per‑frame metadata.

Implementations

impl PageFrameManager

pub const fn new() -> Self

Creates a new uninitialised page frame manager.

The manager is not usable until init() is called.

pub fn init()

Initialises the global page frame manager.

This function:

1. Detects total physical memory and computes the number of frames.
2. Finds a physical memory region large enough to hold the PageFrame array.
3. Maps that region into the kernel’s virtual address space.
4. Initialises each PageFrame with default values.
5. Sets the RESERVED flag for all frames, then clears it for usable RAM entries.
6. Finally reserves the frames that contain the metadata array itself.

Panics

Panics if the memory map is unavailable or if no suitable region is found.

Trait Implementations

impl AbsPageFrameManager for PageFrameManager

fn check_flags(&self, pfn: PageFrameNumber, flag: PageFlags) -> bool

Checks whether a given flag is set on the specified page frame.

fn clear_flags(&self, pfn: PageFrameNumber, flag: PageFlags)

Clears the specified flags on the given page frame.

fn max(&self) -> PageFrameNumber

Returns the maximum possible page frame number.

TODO

This currently returns PFN::MAX, which may be larger than the actual number of frames. A proper implementation should return the highest valid PFN based on the detected memory size.

fn min(&self) -> PageFrameNumber

Returns the minimum possible page frame number (always 0).

fn present(&self, _pfn: PageFrameNumber) -> bool

Returns whether a page frame is physically present.

TODO

This always returns true. A real implementation should validate the PFN against the number of available frames.

fn set_flags(&self, pfn: PageFrameNumber, flag: PageFlags)

Sets the specified flags on the given page frame.

fn get(&self, pfn: PageFrameNumber) -> Self::Access

Returns a locked guard that provides mutable access to the page frame metadata.

type Flags = PageFlags

Type representing flags that can be set on a page frame. Must implement AbsFlags.

type Access = MutexGuard<'static, PageFrame, Spin>

Type used to access a page frame (e.g., a reference or a descriptor).

impl Clone for PageFrameManager

fn clone(&self) -> PageFrameManager

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for PageFrameManager

impl Debug for PageFrameManager

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for PageFrameManager

fn default() -> PageFrameManager

Returns the “default value” for a type.