/*
* Copyright (C) 2006 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <libc.h>
#include <unistd.h>
#include <kernel/mm/as_arg.h>
#include <task.h>
/** Create address space area.
*
* @param address Virtual address where to place new address space area.
* @param size Size of the area.
* @param flags Flags describing type of the area.
*
* @return address on success, (void *) -1 otherwise.
*/
void *as_area_create(void *address, size_t size, int flags)
{
return (void *) __SYSCALL3(SYS_AS_AREA_CREATE, (sysarg_t ) address, (sysarg_t) size, (sysarg_t) flags);
}
/** Resize address space area.
*
* @param address Virtual address pointing into already existing address space area.
* @param size New requested size of the area.
* @param flags Currently unused.
*
* @return address on success, (void *) -1 otherwise.
*/
void *as_area_resize(void *address, size_t size, int flags)
{
return (void *) __SYSCALL3(SYS_AS_AREA_RESIZE, (sysarg_t ) address, (sysarg_t) size, (sysarg_t) flags);
}
/** Prepare to accept address space area.
*
* @param id Task ID of the donor task.
* @param base Destination address for the new address space area.
* @param size Size of the new address space area.
* @param flags Flags of the area TASK is willing to accept.
*
* @return 0 on success or a code from errno.h.
*/
int as_area_accept(task_id_t id, void *base, size_t size, int flags)
{
as_area_acptsnd_arg_t arg;
arg.task_id = id;
arg.base = base;
arg.size = size;
arg.flags = flags;
return __SYSCALL1(SYS_AS_AREA_ACCEPT, (sysarg_t) &arg);
}
/** Send address space area to another task.
*
* @param id Task ID of the acceptor task.
* @param base Source address of the existing address space area.
*
* @return 0 on success or a code from errno.h.
*/
int as_area_send(task_id_t id, void *base)
{
as_area_acptsnd_arg_t arg;
arg.task_id = id;
arg.base = base;
arg.size = 0;
arg.flags = 0;
return __SYSCALL1(SYS_AS_AREA_SEND, (sysarg_t) &arg);
}
static size_t heapsize = 0;
/* Start of heap linker symbol */
extern char _heap;
/** Sbrk emulation
*
* @param size New area that should be allocated or negative,
if it should be shrinked
* @return Pointer to newly allocated area
*/
void *sbrk(ssize_t incr)
{
void *res;
/* Check for invalid values */
if (incr < 0 && -incr > heapsize)
return NULL;
/* Check for too large value */
if (incr > 0 && incr+heapsize < heapsize)
return NULL;
/* Check for too small values */
if (incr < 0 && incr+heapsize > heapsize)
return NULL;
res = as_area_resize(&_heap, heapsize + incr,0);
if (!res)
return NULL;
/* Compute start of new area */
res = (void *)&_heap + heapsize;
heapsize += incr;
return res;
}