#include <common.h>
#include <string.h>
#include <mem/pmm.h>
#include <boot/multiboot.h>

Include dependency graph for pmm.c:

Macros
#define	PAGE_SIZE 4096
	4KB pages

#define	PAGE_SHIFT 12
	bits to shift to get page (2^12=4096)

#define	MEMORY_SIZE 0x100000000
	4GB address space

#define	TYPE_BITS 2
	number of bits per page entry

#define	PAGE_NUMBER (MEMORY_SIZE / PAGE_SIZE)
	total number of pages

#define	ENTRIES 1024
	number of entries in a page table

#define	PAGES_PER_DWORD (32 / TYPE_BITS)
	pages in each bitmap entry

#define	PAGES_BER_BYTE (8 / TYPE_BITS)
	pages per bitmap entry byte

#define	TYPE_MASK (0xFFFFFFFF >> (32 - TYPE_BITS))
	calc 2^TYPE_BITS-1

#define	BITMAP_INIT 0x55555555
	0b0101...01, use PMM_RESERVED

#define	BIT_CHECK(val, bit) (((val) >> (bit)) & 1)
	checks a bit in a given value

#define	BITMAP_SET(idx) (bitmap[(idx) / 32] \|= 1 << ((idx) % 32))
	sets a bit in the memory bitmap

#define	BITMAP_CLEAR(idx) (bitmap[(idx) / 32] &= ~(1 << ((idx) % 32)))
	clears a bit in the memory bitmap

Functions
static void	pmm_bitmap_set (uint32_t idx, uint32_t value)
	Sets a bitmap entry to a value. More...

static uint32_t	pmm_bitmap_get (uint32_t idx)
	Returns a bitmap entry. More...

static void	pmm_use_kernel_memory ()
	Marks all kernel memory as used.

void	pmm_init ()
	Initializes the PMM. More...

uint32_t	pmm_get_page (void *ptr, uint32_t offset)
	Returns to which page a given memory address belongs. More...

void *	pmm_get_address (uint32_t page, uint32_t offset)
	Returns a memory address belonging to a given page. More...

void	pmm_use (void ptr, size_t len, pmm_flags_t flags, char tag)
	Marks page frames for a given memory range as used or unused. More...

static void *	pmm_find_free (size_t len)
	Finds free page frames. More...

void *	pmm_alloc (size_t len, pmm_flags_t flags)
	Allocates page frames. More...

void	pmm_free (void *ptr, size_t len)
	Frees page frames. More...

pmm_flags_t	pmm_check (void *ptr)
	Returns whether a page frame is used or unused. More...

void	pmm_dump (void *ptr, size_t len)
	Dumps information on page frames for a given memory range. More...

uint32_t	pmm_get_highest_kernel_page ()
	Returns the highest page used by the kernel. More...

Variables
static uint32_t	bitmap [PAGE_NUMBER/PAGES_PER_DWORD]
	Holds information on used page frames. More...

static uint32_t	highest_kernel_page = 0
	remember the highest kernel page

const void	kernel_start
	start of the kernel section

const void	kernel_end
	end of the kernel section

const void	main_kernel_stack_end
	end of the main kernel stack

static void *	main_kernel_stack_start
	start of the main kernel stack More...

Macros

Functions