paging.h File Reference

#include <stddef.h>

Go to the source code of this file.

Macros
#define	RUN_IN_ADDRESS_SPACE(addr_space, codeblock)

Functions
void	map_pages (void *virt_addr_ptr, void *phys_addr_ptr, int num_pages, char usr, char wr)
void	unmap_pages (void *start_virt, int num_pages, int free_phys)
void *	alloc_pages (int num_pages)
void	alloc_pages_virt (int num_pages, void *addr)
void	dealloc_pages (int num_pages, void *addr)
void	paging_init ()
void *	paging_new_address_space ()
void	load_address_space (void *address_space)
void *	virt_to_phys (void *virt_addr)
void *	find_free_pages (int num_pages)
void *	get_address_space ()
char	is_page_present (size_t page)

Macro Definition Documentation

RUN_IN_ADDRESS_SPACE

#define RUN_IN_ADDRESS_SPACE	(		addr_space,
			codeblock
	)

Value:

  do { \
  void* old_address_space=get_address_space(); \
  load_address_space(addr_space); \
  codeblock; \
  load_address_space(old_address_space); \
} while(0);

Run a block of code in a different address space

Parameters

addr_space	the address space to use
codeblock	the block of code to run

Function Documentation

alloc_pages()

void* alloc_pages

(

int

num_pages

)

Allocate virtual pages & map them to newly allocated physical memory.

Parameters

num_pages

The number of pages to allocate.

Returns

a pointer to the allocated pages.

alloc_pages_virt()

void alloc_pages_virt	(	int	num_pages,
		void *	addr
	)

Allocate virtual pages at a specific address & map them to newly allocated physical memory.

Parameters

num_pages	The number of pages to allocate.
addr	The adress to start allocation at.

dealloc_pages()

void dealloc_pages	(	int	num_pages,
		void *	addr
	)

Deallocate the physical memory for pages and unmap them

Parameters

num_pages	The number of pages to deallocate.
addr	The adress to start deallocation at.

find_free_pages()

void* find_free_pages

(

int

num_pages

)

Finds free virtual pages and returns the start address

Parameters

num_pages

The minimum size of the free area

Returns

the start of the free area

get_address_space()

void* get_address_space

(

)

Get the current address space

Returns

a pointer to the current address space in physical memory.

is_page_present()

char is_page_present

(

size_t

page

)

Checks whether a page is present

Parameters

page	The page number to check

Returns

Whether the page is present

load_address_space()

void load_address_space

(

void *

address_space

)

Load an address space

Parameters

address_space

The address space to load

map_pages()

void map_pages	(	void *	virt_addr_ptr,
		void *	phys_addr_ptr,
		int	num_pages,
		char	usr,
		char	wr
	)

Map virtual pages to physical frames.

Parameters

virt_addr_ptr	The start of the virtual range to map.
phys_addr_ptr	The start of the physical range to map.
num_pages	The number of pages to map.
usr	Are the pages acessible by user mode code
wr	Are the pages writable by user mode code (kernel always has write permissions)

paging_init()

void paging_init

(

)

Initialize paging

paging_new_address_space()

void* paging_new_address_space

(

)

Create a new address space

Returns

a pointer to the new address space in physical memory.

unmap_pages()

void unmap_pages	(	void *	start_virt,
		int	num_pages,
		int	free_phys
	)

Unmap virtual pages,

Parameters

start_virt	The start of the virtual range to unmap.
num_pages	The number of pages to map.
free_phys	Also free the physical pages the virtual pages are mapped to.

virt_to_phys()

void* virt_to_phys

(

void *

virt_addr

)

Convert a virtual address to a physical one.

Parameters

virt_addr

The virtual address to convert

Returns

the physical adress it maps to, or NULL if it is not mapped.