lmlib

Data Structures
struct	mmap_t

Functions
void *	lm_init (void)
	Initializes the low memory area, the region up to the 1 MByte physical address, by mapping it on the process' physical memory address.
void *	lm_alloc (unsigned long size, mmap_t *map)
	Allocates a memory block in low memory area with the specified size.
void	lm_free (mmap_t *map)
	Frees a memory block in the low memory area, previously allocated using lm_alloc()

Variables
phys_bytes	mmap_t::phys
	physical address
void *	mmap_t::virtual
	virtual address
unsigned long	mmap_t::size
	size of memory region

Detailed Description

Functions related to low memory (first 1 MB of physical memory), required for BIOS

Function Documentation

void* lm_init

(

void

)

Initializes the low memory area, the region up to the 1 MByte physical address, by mapping it on the process' physical memory address.

Returns

virtual address on which the first 1 MiB was mapped, NULL upon failure

void* lm_alloc	(	unsigned long	size,
		mmap_t *	map
	)

Allocates a memory block in low memory area with the specified size.

Allocates a memory block in the region up to the 1 MByte physical address with the input size. Initializes the input mmap_t struct with the maping information, which can be read but must not be modified.

Parameters

size	size of the memory block to allocate
map	pointer to mmap_t data structure, which represents the memory map

Returns

the virtual address of the memory block on success, NULL otherwise

void lm_free

(

mmap_t *

map

)

Frees a memory block in the low memory area, previously allocated using lm_alloc()

Frees a memory block in the region up to the 1 MByte physical addess, previously allocated using lm_alloc(). Takes as input the address of the mmap_t structure that was passed to lm_alloc(), and that must have not been modified since.

Parameters

map	pointer to mmap_t data structure of the block being freed