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 🔒
  Implementation of physical and virtual address and page number.
• frame_allocator 🔒
  Implementation of FrameAllocator which controls all the frames in the operating system.
• heap_allocator 🔒
  The global allocator
• memory_set 🔒
  Implementation of MapArea and MemorySet.
• page_table 🔒
  Implementation of PageTableEntry and PageTable.

Structs

• FrameTracker
  manage a frame which has the same lifecycle as the tracker
• KERNEL_SPACE
  a memory set instance through lazy_static! managing kernel space
• MapPermission
  map permission corresponding to that in pte: R W X U
• MemorySet
  memory set structure, controls virtual-memory space
• PageTable
  Record root ppn and has the same lifetime as 1 and 2 level PageTableEntry
• PageTableEntry
  page table entry structure
• PhysAddr
  Definitions
• PhysPageNum
  phiscal page number
• UserBuffer
  Array of u8 slice that user communicate with os
• UserBufferIterator
  Iterator of UserBuffer
• VirtAddr
  virtual address
• VirtPageNum
  virtual page number

Traits

• StepByOne
  Add value by one

Functions

• frame_alloc
  allocate a frame
• frame_dealloc
  deallocate a frame
• init
  initiate heap allocator, frame allocator and kernel space
• kernel_token
  Get kernelspace root ppn
• remap_test
  Check PageTable running correctly
• translated_byte_buffer
  Translate a pointer to a mutable u8 Vec through page table
• translated_ref
  Translate a generic through page table and return a reference
• translated_refmut
  Translate a generic through page table and return a mutable reference
• translated_str
  Translate a pointer to a mutable u8 Vec end with \0 through page table to a String