heap.c

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/*
  ----- heap.c -----

  Description..: Heap management procedures.
*/

#include <system.h>
#include <string.h>

#include <core/serial.h>
#include <mem/heap.h>
#include <mem/paging.h>

heap* kheap = 0; //kernel heap
heap* curr_heap = 0; //current heap

extern page_dir *kdir; //kernel page directory
extern void* end, _end, __end; //kernel end; defined in link.ld

//physical placement address
//current physical memory allocation address
u32int phys_alloc_addr = (u32int)&end;

u32int _kmalloc(u32int size, int page_align, u32int *phys_addr)
{
  u32int *addr;

  // Allocate on the kernel heap if one has been created
  if (kheap != 0){
    addr = (u32int*)alloc(size, kheap, page_align);
    if (phys_addr){
      page_entry *page = get_page((u32int)addr, kdir, 0);
      *phys_addr = (page->frameaddr*0x1000) + ((u32int)addr & 0xFFF);
    }
    return (u32int)addr;
  }
  // Else, allocate directly from physical memory
  else {
    if (page_align && (phys_alloc_addr & 0xFFFFF000)){
      phys_alloc_addr &= 0xFFFFF000;
      phys_alloc_addr += 0x1000;
    }
    addr = (u32int*)phys_alloc_addr;
    if (phys_addr){
      *phys_addr = phys_alloc_addr;
    }
    phys_alloc_addr += size;
    return (u32int)addr;
  }
}

u32int kmalloc(u32int size)
{
  return _kmalloc(size,0,0);
}

u32int alloc(u32int size, heap *h, int align)
{
  no_warn(size||align||h);
  static u32int heap_addr = KHEAP_BASE;

  u32int base = heap_addr;
  heap_addr += size;

  if (heap_addr > KHEAP_BASE + KHEAP_MIN)
    serial_println("Heap is full!");

  return base;
}

heap* make_heap(u32int base, u32int max, u32int min)
{  
  no_warn(base||max||min);
  return (heap*)kmalloc(sizeof(heap));
}