os-core/kernel/leos/memory.c

55 lines
1.1 KiB
C

/******************************************************************************
*
* Copyright (c) 2017-2020 by Löwenware Ltd
* Please, refer LICENSE file for legal information
*
******************************************************************************/
/**
unsigned
* @file memory.c
* @author Ilja Kartašov <ik@lowenware.com>
* @brief
*
* @see https://lowenware.com/
*/
#include <stdlib.h>
#include <drivers/soc/bcm2837/bcm2837.h>
#include "memory.h"
static unsigned long m_map[MEMORY_PAGE_COUNT / sizeof(unsigned long) / 8] = {0,};
static int m_ix = 0;
void *
Memory_getPage(void)
{
int i, j;
unsigned long map;
for (i = m_ix; i < sizeof(m_map) / sizeof(m_map[0]); i++) {
map = m_map[i];
for (j = 0; j < 8 * sizeof(map); j++) {
if (!(map & (1 << j))) {
m_map[i] |= (1 << j);
return (void *) ((i * sizeof(map) * 8 + j) * MEMORY_PAGE_SIZE);
}
}
m_ix = i;
}
return NULL;
}
void
Memory_freePage(void *p_addr)
{
int i, j, c;
c = ((unsigned long) p_addr) / MEMORY_PAGE_SIZE;
i = c / sizeof(m_map[0]);
j = c % sizeof(m_map[0]);
m_map[i] &= ~(1 << j);
}