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