Memory Management
=================

Memory management is split into three layers: physical, virtual & the heap.

pmm.h
-----
The **physical memory manager** (PMM) is responsible for allocating physical
memory. It gives `pmm_*` functions. The `pmm_allocPage()` function allocates a
4kB page frame and retuns its **physical address**.

vmm.h
-----
The **virtual memory manager** (VMM) is responsible for allocating virtual
memory. It provides `vmm_*` functions. The `vmm_alloc()` function takes in a
number of 4kB pages to allocate and returns the **virtual address** of the
first page. Userspace can interface with the VMM using the `mmap()` and
`munmap()` syscalls.

kmalloc.h
---------
The `kmalloc.h` header provides memory management functions for kernel memory.

`void* kmalloc(size_t size)`
****************************
**Parameters**
* `size_t size` - Number of bytes to allocate

**Descriptions**
This function allocates `size` bytes of contiguous memory.

**Returns**
A pointer to allocated memory or NULL.

`void* kzalloc(size_t size)`
****************************
**Parameters**
* `size_t size` - Number of bytes to allocate

**Description**
This function allocates `size` bytes of contiguous, zeroed-out memory.

**Returns**
A pointer to allocated memory or NULL.

`void* kcalloc(size_t count, size_t size)`
******************************************
**Parameters**
* `size_t count` -