#include <uart.h>
#include <errcode.h>
#include <utils.h>
#include <kmalloc.h>
#include <stddef.h>

extern uint64_t __heap_start;
extern uint64_t __heap_end;

void *_heap_top = (void *)0;

// simple 8-byte aligned linear allocation
void *simple_alloc(size_t size)
{
  if (!_heap_top) {
    _heap_top = (void *)&__heap_start;
  }

  size = (size_t)ALIGN8(size);
  
  if ((uint64_t)_heap_top + size >= (uint64_t)&__heap_end)
    exit(ERR_NO_MEM);

  void *ret = _heap_top;
  _heap_top = (void *)((uint64_t)_heap_top + size);

  return ret;
}

void *kmalloc(size_t size)
{
  return simple_alloc(size);
}

void kfree(void *ptr)
{
  // not implemented for now
  return;
}