68 lines
2.1 KiB
C
68 lines
2.1 KiB
C
/*-
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* Copyright 2018 Toomas Soome <tsoome@me.com>
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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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#include <stand.h>
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#include "libi386.h"
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/*
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* The idea is borrowed from pxe.c and zfsimpl.c. The original buffer
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* space in pxe.c was 2x 0x2000. Allocating it from BSS will give us needed
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* memory below 1MB and usable for real mode calls.
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*
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* Note the allocations and frees are to be done in reverse order (LIFO).
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*/
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static char bio_buffer[BIO_BUFFER_SIZE];
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static char *bio_buffer_end = bio_buffer + BIO_BUFFER_SIZE;
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static char *bio_buffer_ptr = bio_buffer;
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void *
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bio_alloc(size_t size)
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{
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char *ptr;
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ptr = bio_buffer_ptr;
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if (ptr + size > bio_buffer_end)
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return (NULL);
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bio_buffer_ptr += size;
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return (ptr);
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}
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void
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bio_free(void *ptr, size_t size)
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{
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if (ptr == NULL)
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return;
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bio_buffer_ptr -= size;
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if (bio_buffer_ptr != ptr)
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panic("bio_alloc()/bio_free() mismatch\n");
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}
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