42 lines
1.3 KiB
C
42 lines
1.3 KiB
C
|
/* sbrk for MMIXware.
|
||
|
|
|
||
|
|
Copyright (C) 2001 Hans-Peter Nilsson.
|
||
|
|
|
||
|
|
Permission to use, copy, modify, and distribute this software is freely
|
||
|
|
granted, provided that this notice is preserved with no changes.
|
||
|
|
THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
|
||
|
|
IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
|
||
|
|
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
||
|
|
PURPOSE. */
|
||
|
|
|
||
|
|
#include <_ansi.h>
|
||
|
|
#include <sys/types.h>
|
||
|
|
#include <sys/stat.h>
|
||
|
|
#include "sys/syscall.h"
|
||
|
|
|
||
|
|
extern char *_Sbrk_high;
|
||
|
|
|
||
|
|
/* When the program is loaded, the first location in Pool_Segment holds
|
||
|
|
the first available octabyte in the memory pool (a.k.a. the heap);
|
||
|
|
somewhere after the command-line parameters. We don't have to
|
||
|
|
initialize that location, we can just use it straight up as a pointer;
|
||
|
|
just point the symbol there.
|
||
|
|
|
||
|
|
This file will be compiled with -no-builtin-syms, so we need to define
|
||
|
|
Pool_Segment and any other symbols that would be predefined in mmixal. */
|
||
|
|
|
||
|
|
__asm__ (" .global _Sbrk_high\n"
|
||
|
|
"_Sbrk_high IS Pool_Segment\n"
|
||
|
|
"Pool_Segment IS 0x40<<56");
|
||
|
|
|
||
|
|
caddr_t
|
||
|
|
_sbrk (size_t incr)
|
||
|
|
{
|
||
|
|
extern char end; /* Defined by the linker */
|
||
|
|
char *prev_heap_end;
|
||
|
|
|
||
|
|
prev_heap_end = _Sbrk_high;
|
||
|
|
_Sbrk_high += incr;
|
||
|
|
return (caddr_t) prev_heap_end;
|
||
|
|
}
|