xref: /netbsd-src/sys/arch/ews4800mips/stand/common/datafs.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: datafs.c,v 1.1 2005/12/29 15:20:09 tsutsui Exp $	*/
2 
3 /*-
4  * Copyright (c) 2004 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by UCHIYAMA Yasushi.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 #include <lib/libsa/stand.h>
40 #include <lib/libkern/libkern.h>
41 
42 #include "local.h"
43 
44 FS_DEF(data);
45 
46 struct fs_ops datafs_ops = {
47 	data_open, data_close, data_read, data_write, data_seek, data_stat
48 };
49 
50 struct datafs {
51 	uint8_t *ptr;
52 	uint8_t *end;
53 	uint8_t *start;
54 	size_t size;
55 } __data;
56 
57 void
58 data_attach(void *addr, size_t size)
59 {
60 
61 	__data.start = addr;
62 	__data.size = size;
63 }
64 
65 int
66 data_open(const char *name, struct open_file *f)
67 {
68 
69 	if (__data.size == 0) {
70 		printf("no data\n");
71 		return -1;
72 	}
73 
74 	__data.ptr = __data.start;
75 	__data.end = __data.ptr + __data.size;
76 
77 	return 0;
78 }
79 
80 int
81 data_close(struct open_file *f)
82 {
83 
84 	return 0;
85 }
86 
87 int
88 data_read(struct open_file *f, void *buf, size_t size, size_t *resid)
89 {
90 	uint8_t *b = buf;
91 	size_t sz;
92 
93 	twiddle();
94 	if (__data.ptr + size < __data.end) {
95 		sz = size;
96 		memcpy(b, __data.ptr, sz);
97 		__data.ptr += sz;
98 	} else {
99 		sz = (size_t)(__data.end - __data.ptr);
100 		while (__data.ptr < __data.end)
101 			*b++ = *__data.ptr++;
102 	}
103 
104 	if (resid)
105 		*resid = size - sz;
106 
107 	return 0;
108 }
109 
110 int
111 data_write(struct open_file *f, void *start, size_t size, size_t *resid)
112 {
113 
114 	return 0;
115 }
116 
117 off_t
118 data_seek(struct open_file *f, off_t offset, int where)
119 {
120 	uint8_t *p = 0;
121 
122 	switch (where) {
123 	case SEEK_SET:
124 		p = __data.start + offset;
125 		break;
126 	case SEEK_CUR:
127 		p = __data.ptr + offset;
128 		break;
129 	case SEEK_END:
130 		p = __data.end + offset;
131 		break;
132 	default:
133 		return EINVAL;
134 	}
135 
136 	if (p < __data.start || p >= __data.end) {
137 		return EINVAL;
138 	}
139 
140 	__data.ptr = p;
141 
142 	return (off_t)(p - __data.start);
143 }
144 
145 int
146 data_stat(struct open_file *f, struct stat *stat)
147 {
148 
149 	stat->st_size = __data.size;
150 
151 	return 0;
152 }
153