L4Re - L4 Runtime Environment
examples/libs/l4re/c/ma+rm.c

Coarse grained memory allocation, in C.

/*
* (c) 2009 Adam Lackorzynski <adam@os.inf.tu-dresden.de>
* economic rights: Technische Universit├Ąt Dresden (Germany)
*
* This file is part of TUD:OS and distributed under the terms of the
* GNU General Public License 2.
* Please see the COPYING-GPL-2 file for details.
*/
#include <l4/re/c/rm.h>
#include <l4/sys/err.h>
#include <stdio.h>
#include <string.h>
static int allocate_mem(unsigned long size_in_bytes, unsigned long flags,
void **virt_addr)
{
int r;
/* Allocate a free capability index for our data space */
return -L4_ENOMEM;
size_in_bytes = l4_trunc_page(size_in_bytes);
/* Allocate memory via a dataspace */
if ((r = l4re_ma_alloc(size_in_bytes, ds, flags)))
return r;
/* Make the dataspace visible in our address space */
*virt_addr = 0;
if ((r = l4re_rm_attach(virt_addr, size_in_bytes,
flags & L4RE_MA_SUPER_PAGES
{
/* Free dataspace again */
return r;
}
/* Done, virtual address is in virt_addr */
return 0;
}
static int free_mem(void *virt_addr)
{
int r;
/* Detach memory from our address space */
if ((r = l4re_rm_detach_ds(virt_addr, &ds)))
return r;
/* Free memory at our memory allocator */
/* All went ok */
return 0;
}
int main(void)
{
void *virt;
/* Allocate memory: 16k Bytes (usually) */
if (allocate_mem(4 * L4_PAGESIZE, 0, &virt))
return 1;
printf("Allocated memory.\n");
/* Do something with the memory */
memset(virt, 0x12, 4 * L4_PAGESIZE);
printf("Touched memory.\n");
/* Free memory */
if (free_mem(virt))
return 2;
printf("Freed and done. Bye.\n");
return 0;
}