1*ca987d46SWarner Losh /*
2*ca987d46SWarner Losh * $NetBSD: pread.c,v 1.2 1997/03/22 01:48:38 thorpej Exp $
3*ca987d46SWarner Losh */
4*ca987d46SWarner Losh
5*ca987d46SWarner Losh /*-
6*ca987d46SWarner Losh * Copyright (c) 1996
7*ca987d46SWarner Losh * Matthias Drochner. All rights reserved.
8*ca987d46SWarner Losh *
9*ca987d46SWarner Losh * Redistribution and use in source and binary forms, with or without
10*ca987d46SWarner Losh * modification, are permitted provided that the following conditions
11*ca987d46SWarner Losh * are met:
12*ca987d46SWarner Losh * 1. Redistributions of source code must retain the above copyright
13*ca987d46SWarner Losh * notice, this list of conditions and the following disclaimer.
14*ca987d46SWarner Losh * 2. Redistributions in binary form must reproduce the above copyright
15*ca987d46SWarner Losh * notice, this list of conditions and the following disclaimer in the
16*ca987d46SWarner Losh * documentation and/or other materials provided with the distribution.
17*ca987d46SWarner Losh * 3. All advertising materials mentioning features or use of this software
18*ca987d46SWarner Losh * must display the following acknowledgement:
19*ca987d46SWarner Losh * This product includes software developed for the NetBSD Project
20*ca987d46SWarner Losh * by Matthias Drochner.
21*ca987d46SWarner Losh * 4. The name of the author may not be used to endorse or promote products
22*ca987d46SWarner Losh * derived from this software without specific prior written permission.
23*ca987d46SWarner Losh *
24*ca987d46SWarner Losh * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25*ca987d46SWarner Losh * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26*ca987d46SWarner Losh * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27*ca987d46SWarner Losh * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28*ca987d46SWarner Losh * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29*ca987d46SWarner Losh * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30*ca987d46SWarner Losh * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31*ca987d46SWarner Losh * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32*ca987d46SWarner Losh * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33*ca987d46SWarner Losh * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34*ca987d46SWarner Losh */
35*ca987d46SWarner Losh
36*ca987d46SWarner Losh /* read into destination in flat addr space */
37*ca987d46SWarner Losh
38*ca987d46SWarner Losh #include <stand.h>
39*ca987d46SWarner Losh
40*ca987d46SWarner Losh #include "libi386.h"
41*ca987d46SWarner Losh
42*ca987d46SWarner Losh #ifdef SAVE_MEMORY
43*ca987d46SWarner Losh #define BUFSIZE (1*1024)
44*ca987d46SWarner Losh #else
45*ca987d46SWarner Losh #define BUFSIZE (4*1024)
46*ca987d46SWarner Losh #endif
47*ca987d46SWarner Losh
48*ca987d46SWarner Losh static char buf[BUFSIZE];
49*ca987d46SWarner Losh
50*ca987d46SWarner Losh int
pread(fd,dest,size)51*ca987d46SWarner Losh pread(fd, dest, size)
52*ca987d46SWarner Losh int fd;
53*ca987d46SWarner Losh vm_offset_t dest;
54*ca987d46SWarner Losh int size;
55*ca987d46SWarner Losh {
56*ca987d46SWarner Losh int rsize;
57*ca987d46SWarner Losh
58*ca987d46SWarner Losh rsize = size;
59*ca987d46SWarner Losh while (rsize > 0) {
60*ca987d46SWarner Losh int count, got;
61*ca987d46SWarner Losh
62*ca987d46SWarner Losh count = (rsize < BUFSIZE ? rsize : BUFSIZE);
63*ca987d46SWarner Losh
64*ca987d46SWarner Losh got = read(fd, buf, count);
65*ca987d46SWarner Losh if (got < 0)
66*ca987d46SWarner Losh return (-1);
67*ca987d46SWarner Losh
68*ca987d46SWarner Losh /* put to physical space */
69*ca987d46SWarner Losh vpbcopy(buf, dest, got);
70*ca987d46SWarner Losh
71*ca987d46SWarner Losh dest += got;
72*ca987d46SWarner Losh rsize -= got;
73*ca987d46SWarner Losh if (got < count)
74*ca987d46SWarner Losh break; /* EOF */
75*ca987d46SWarner Losh }
76*ca987d46SWarner Losh return (size - rsize);
77*ca987d46SWarner Losh }
78