kernel: Remove some more old headers.
[dragonfly.git] / sys / boot / common / load.c
CommitLineData
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1/*-
2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
5ee58eed 26 * $FreeBSD: src/sys/boot/common/load.c,v 1.3 2003/08/25 23:30:41 obrien Exp $
79dc5fc6 27 * $DragonFly: src/sys/boot/common/load.c,v 1.4 2008/09/02 17:21:12 dillon Exp $
984263bc 28 */
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29#include <stand.h>
30
31#define LOAD_TINYBUF 2048
32
33/*
34 * Attempt to load the file at (path) into an allocated
35 * area on the heap, return a pointer to it or NULL
36 * on failure.
37 *
38 * Because in many cases it is impossible to determine the
39 * true size of a file without reading it, we do just that.
40 */
41char *
42filedup(const char *path, int flags)
43{
44 char *buf;
45 int fd;
46 size_t size, result;
47
116b7e3c 48 if ((fd = rel_open(path, NULL, F_READ | flags)) == -1)
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49 return(NULL);
50
51 printf("%s open, flags 0x%x\n", path, files[fd].f_flags);
52 buf = alloc(LOAD_TINYBUF);
53
54 /* Read the first buffer-full */
55 size = read(fd, buf, LOAD_TINYBUF);
56 if (size < 1) {
57 free(buf, LOAD_TINYBUF);
58 close(fd);
59 return(NULL);
60 }
61 /* If it all fitted, then just return the buffer straight out */
62 if (size < LOAD_TINYBUF) {
63 close(fd);
64 buf[size] = 0;
65 return(buf);
66 }
67
68 printf("tinybuf loaded, size %d\n", size);
69 getchar();
70
71
72 /* Read everything until we know how big it is */
73 for (;;) {
74 result = read(fd, buf, LOAD_TINYBUF);
75 if (size == -1) {
76 free(buf, LOAD_TINYBUF);
77 close(fd);
78 return(NULL);
79 }
80 if (result == 0)
81 break;
82 size += result;
83 }
84
85 /* discard the old buffer, close the file */
86 free(buf, LOAD_TINYBUF);
87 close(fd);
88
89 /* reopen the file, realloc the buffer */
116b7e3c 90 if ((fd = rel_open(path, NULL, F_READ | flags)) == -1)
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91 return(NULL);
92 buf = alloc(size);
93 result = read(fd, buf, size);
94 close(fd);
95 if (result != size) {
96 free(buf, size);
97 return(NULL);
98 }
99 return(buf);
100}
101