/*
* Copyright (c) 1996
* Matthias Drochner. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* 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.
*
*/
/* data buffer for BIOS disk / DOS I/O */
#include <sys/inttypes.h>
#include <lib/libsa/stand.h>
#include "diskbuf.h"
char *diskbufp; /* allocated from heap */
const void *diskbuf_user;
/*
* Global shared "diskbuf" is used as read ahead buffer.
* This MAY have to not cross a 64k boundary.
* In practise it is allocated out of the heap early on...
* NB a statically allocated diskbuf is not guaranteed to not
* cross a 64k boundary.
*/
char *
alloc_diskbuf(const void *user)
{
diskbuf_user = user;
if (!diskbufp) {
diskbufp = alloc(DISKBUFSIZE);
#ifndef EFIBOOT
if (((uintptr_t)diskbufp & 0xffff) + DISKBUFSIZE > 0x10000) {
printf("diskbufp %" PRIxPTR "\n", (uintptr_t)diskbufp);
panic("diskbuf crosses 64k boundary");
}
#endif
}
return diskbufp;
}
