68 lines
2.1 KiB
C
68 lines
2.1 KiB
C
/*-
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* Copyright (c) 1998 Michael Smith
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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/*
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* Minimal sbrk() emulation required for malloc support.
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*/
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#include <string.h>
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#include "stand.h"
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#include "zalloc_defs.h"
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static size_t maxheap, heapsize = 0;
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static void *heapbase;
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void
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setheap(void *base, void *top)
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{
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/* Align start address for the malloc code. Sigh. */
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heapbase = (void *)(((uintptr_t)base + MALLOCALIGN_MASK) &
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~MALLOCALIGN_MASK);
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maxheap = (char *)top - (char *)heapbase;
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}
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char *
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sbrk(int incr)
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{
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char *ret;
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if (heapbase == 0)
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panic("No heap setup\n");
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if ((heapsize + incr) <= maxheap) {
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ret = (char *)heapbase + heapsize;
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bzero(ret, incr);
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heapsize += incr;
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return(ret);
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}
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errno = ENOMEM;
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return((char *)-1);
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}
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