Struct sunrise_kernel::frame_allocator::FrameAllocator

pub struct FrameAllocator;

The physical memory manager.

Serves physical memory in atomic blocks of size PAGE_SIZE, called frames.

An allocation request returns a PhysicalMemRegion, which represents a list of physically adjacent frames. When this returned PhysicalMemRegion is eventually dropped the frames are automatically freed and can be re-served by the FrameAllocator.

Trait Implementations

impl Debug for FrameAllocator

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

Formats the value using the given formatter.

impl FrameAllocatorTrait for FrameAllocator

fn allocate_region(length: usize) -> Result<PhysicalMemRegion, KernelError>

Allocates a single PhysicalMemRegion. Frames are physically consecutive.

Errors

• InvalidSize
  • length is not page size aligned.
  • length is 0.

Panics

• Panics if FRAME_ALLOCATOR was not initialized.

fn allocate_frames_fragmented(
    length: usize
) -> Result<Vec<PhysicalMemRegion>, KernelError>

Allocates physical frames, possibly fragmented across several physical regions.

Errors

• InvalidSize:
  • length is not page size aligned.
  • length is 0.

Panics

• Panics if FRAME_ALLOCATOR was not initialized.

fn allocate_frame() -> Result<PhysicalMemRegion, KernelError>

Allocates a single physical frame.

impl FrameAllocatorTraitPrivate for FrameAllocator

fn free_region(region: &PhysicalMemRegion)

Frees an allocated physical region.

Panic

• Panics if the frame was not allocated.
• Panics if FRAME_ALLOCATOR was not initialized.

fn check_is_allocated(address: PhysicalAddress, length: usize) -> bool

Checks that a physical region is marked allocated.

Rounds address and length.

Panic

• Panics if FRAME_ALLOCATOR was not initialized.

fn check_is_reserved(address: PhysicalAddress, length: usize) -> bool

Checks that a physical region is marked reserved. This implementation does not distinguish between allocated and reserved frames, so for us it's equivalent to check_is_allocated.

Rounds address and length.

Panic

• Panics if FRAME_ALLOCATOR was not initialized.