Module os::mm

Memory management implementation

SV39 page-based virtual-memory architecture for RV64 systems, and everything about memory management, like frame allocator, page table, map area and memory set, is implemented here.

Every task or process has a memory_set to control its virtual memory.

Re-exports

• pub use memory_set::KERNEL_SPACE;
• pub use memory_set::KERNEL_SPACE;

Modules

• address 🔒
  PhysAddr, VirtAddr, PhysPageNum, VirtPageNum, raw address
• frame_allocator 🔒
  Physical page frame allocator
• heap_allocator 🔒
  The heap allocator.
• memory_set 🔒
  Address Space MemorySet management of Process
• page_table 🔒
  Implementation of PageTableEntry and PageTable.

Structs

• FrameTracker
  tracker for physical page frame allocation and deallocation
• KERNEL_SPACE
  The kernel’s initial memory mapping(kernel address space)
• MapPermission
  map permission corresponding to that in pte: R W X U
• MemorySet
  address space
• PageTable
  page table structure
• PageTableEntry
  page table entry structure
• PhysAddr
  Physical Address
• PhysPageNum
  Physical Page Number PPN
• UserBuffer
  An abstraction over a buffer passed from user space to kernel space
• UserBufferIterator
  An iterator over a UserBuffer
• VirtAddr
  Virtual Address
• VirtPageNum
  Virtual Page Number VPN

Traits

• StepByOne
  iterator for phy/virt page number

Functions

• frame_alloc
  Allocate a physical page frame in FrameTracker style
• frame_dealloc
  Deallocate a physical page frame with a given ppn
• init
  initiate heap allocator, frame allocator and kernel space
• kernel_token
  the kernel token
• remap_test
  test map function in page table
• translated_byte_buffer
  Create mutable Vec<u8> slice in kernel space from ptr in other address space. NOTICE: the content pointed to by the pointer ptr can cross physical pages.
• translated_ref
  translate a pointer ptr in other address space to a immutable u8 slice in kernel address space. NOTICE: the content pointed to by the pointer ptr cannot cross physical pages, otherwise translated_byte_buffer should be used.
• translated_refmut
  translate a pointer ptr in other address space to a mutable u8 slice in kernel address space. NOTICE: the content pointed to by the pointer ptr cannot cross physical pages, otherwise translated_byte_buffer should be used.
• translated_str
  Create String in kernel address space from u8 Array(end with 0) in other address space