libc/libgloss/mep/sbrk.c
Jeff Johnston 1d94f73114 2007-02-08 Dave Brolley <brolley@redhat.com>
* mep: New target directory.
        * README: Add MeP.
        * configure.in: Add support for MeP.
        * configure: Regenerated.
        * mep/configure.in: New file.
        * mep/configure: Ditto.
        * mep/Makefile.in: Ditto.
        * mep/aclocal.m4: Ditto.
        * mep/crt0.S: Ditto.
        * mep/crtn.S: Ditto.
        * mep/sim-crt0.S: Ditto.
        * mep/sim-crtn.S: Ditto.
        * mep/fmax.ld: Ditto.
        * mep/gcov-io.h: Ditto.
        * mep/gmap_default.ld: Ditto.
        * mep/handlers.c: Ditto.
        * mep/h_reset.c: Ditto.
        * mep/isatty.c: Ditto.
        * mep/mep-bb.c: Ditto.
        * mep/mep-gmon.c: Ditto.
        * mep/min.ld: Ditto.
        * mep/read.c: Ditto.
        * mep/sbrk.c: Ditto.
        * mep/sdram-crt0.S: Ditto.
        * mep/sdram-crtn.S: Ditto.
        * mep/simnovec-crt0.S: Ditto.
        * mep/simple.ld: Ditto.
        * mep/simsdran-crt0.S: Ditto.
        * mep/syscalls.S: Ditto.
        * mep/write.c: Ditto.
2007-02-08 21:22:05 +00:00

60 lines
1.5 KiB
C

/*
* Copyright (c) 2003 Red Hat, Inc. All rights reserved.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the BSD
* License. This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY expressed or implied, including the implied
* warranties of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. A copy
* of this license is available at http://www.opensource.org/licenses. Any
* Red Hat trademarks that are incorporated in the source code or documentation
* are not subject to the BSD License and may only be used or replicated with
* the express permission of Red Hat, Inc.
*/
#include <errno.h>
extern int __heap __far; /* beginning of heap */
extern int __heap_end __far; /* if at address 0, use stack pointer as limit */
static char *the_break = (char *)(& __heap);
int
is_addr_0 (int address)
{
return address ? 0 : 1;
}
void *
sbrk(int inc)
{
char *current_heap_limit = (char *) (& __heap_end);
/* is_addr_0 avoids optimizing out this block. */
if (is_addr_0 ((int) current_heap_limit))
{
int something;
int margin = 4096;
current_heap_limit = (char *) (& something) - margin;
}
if ((the_break + inc) < current_heap_limit)
{
void *rv = (void *) the_break;
the_break += inc;
return rv;
}
else
{
errno = ENOMEM;
return (void *) -1;
}
}
int
brk (void *ptr)
{
the_break = ptr;
return 0;
}