Module mm

memory management unit

Modules

• pma 🔒
  (deprecated) a simple stack based 4K physical frame allocator.
• vmm
  a very simple virtual memory manager

Structs

• KSTACK_ALLOCATOR
• KStackAllocator
  wrapper around the global allocator with caching

Constants

• LAYOUT_4K_ALIGNED 🔒

Statics

• ALLOCATOR 🔒

Functions

• allocate_4k
  allocate 4k aligned memory. TODO create a buffer (like in KStackAllocator) for performance.
• allocate_4k_zeroed
• drop_init_mapping^⚠
  drop the low memory mapping from the current pagetable by removing the first entry from pml4 table (which mapps to 0~512G). The PDP table is unchanged, wasting 4K of memory but there is nothing we can do now since the heap allocator doesn’t manage this address.
• flush_tlb
  flush the whole tlb
• init
  half measure: simply initialize the linkedlist allocator
• invlpg
  invalidate a single page mapping in tlb