1 /*
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright © 2019 Keith Packard
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above
14 * copyright notice, this list of conditions and the following
15 * disclaimer in the documentation and/or other materials provided
16 * with the distribution.
17 *
18 * 3. Neither the name of the copyright holder nor the names of its
19 * contributors may be used to endorse or promote products derived
20 * from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
26 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
27 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
28 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
29 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
31 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
33 * OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35
36 #include "semihost-private.h"
37 #include <sys/types.h>
38 #include <sys/stat.h>
39 #include <fcntl.h>
40 #include <unistd.h>
41 #include <errno.h>
42
lseek(int fd,off_t offset,int whence)43 off_t lseek(int fd, off_t offset, int whence)
44 {
45 if (whence == SEEK_CUR && offset == 0)
46 return 0;
47
48 if (whence == SEEK_END) {
49 int flen = sys_semihost_flen(fd);
50 if (flen != -1) {
51 whence = SEEK_SET;
52 offset += flen;
53 }
54 }
55
56 if (whence != SEEK_SET) {
57 errno = EINVAL;
58 return (off_t) -1;
59 }
60
61 struct {
62 sh_param_t field1;
63 sh_param_t field2;
64 } arg = {
65 .field1 = fd,
66 .field2 = offset
67 };
68
69 uintptr_t ret = sys_semihost(SYS_SEEK, (uintptr_t) &arg);
70 if (ret == 0)
71 return offset;
72 errno = sys_semihost_errno();
73 return -1;
74 }
75
