1 /*-
2 * Copyright (c) 2009 Marcel Moolenaar
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 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29
30 #include <stand.h>
31 #include <sys/param.h>
32 #include <sys/endian.h>
33 #include <sys/queue.h>
34 #include <machine/stdarg.h>
35
36 #include "bootstrap.h"
37
38 #define MD_BLOCK_SIZE 512
39
40 #ifndef MD_IMAGE_SIZE
41 #error Must be compiled with MD_IMAGE_SIZE defined
42 #endif
43 #if (MD_IMAGE_SIZE == 0 || MD_IMAGE_SIZE % MD_BLOCK_SIZE)
44 #error Image size must be a multiple of 512.
45 #endif
46
47 /*
48 * Preloaded image gets put here.
49 * Applications that patch the object with the image can determine
50 * the size looking at the start and end markers (strings),
51 * so we want them contiguous.
52 */
53 static struct {
54 u_char start[MD_IMAGE_SIZE];
55 u_char end[128];
56 } md_image = {
57 .start = "MFS Filesystem goes here",
58 .end = "MFS Filesystem had better STOP here",
59 };
60
61 /* devsw I/F */
62 static int md_init(void);
63 static int md_strategy(void *, int, daddr_t, size_t, char *, size_t *);
64 static int md_open(struct open_file *, ...);
65 static int md_close(struct open_file *);
66 static int md_print(int);
67
68 struct devsw md_dev = {
69 "md",
70 DEVT_DISK,
71 md_init,
72 md_strategy,
73 md_open,
74 md_close,
75 noioctl,
76 md_print
77 };
78
79 static int
md_init(void)80 md_init(void)
81 {
82
83 return (0);
84 }
85
86 static int
md_strategy(void * devdata,int rw,daddr_t blk,size_t size,char * buf,size_t * rsize)87 md_strategy(void *devdata, int rw, daddr_t blk, size_t size, char *buf,
88 size_t *rsize)
89 {
90 struct devdesc *dev = (struct devdesc *)devdata;
91 size_t ofs;
92
93 if (dev->d_unit != 0)
94 return (ENXIO);
95
96 if (blk < 0 || blk >= (MD_IMAGE_SIZE / MD_BLOCK_SIZE))
97 return (EIO);
98
99 if (size % MD_BLOCK_SIZE)
100 return (EIO);
101
102 ofs = blk * MD_BLOCK_SIZE;
103 if ((ofs + size) > MD_IMAGE_SIZE)
104 size = MD_IMAGE_SIZE - ofs;
105
106 if (rsize != 0)
107 *rsize = size;
108
109 switch (rw & F_MASK) {
110 case F_READ:
111 bcopy(md_image.start + ofs, buf, size);
112 return (0);
113 case F_WRITE:
114 bcopy(buf, md_image.start + ofs, size);
115 return (0);
116 }
117
118 return (ENODEV);
119 }
120
121 static int
md_open(struct open_file * f,...)122 md_open(struct open_file *f, ...)
123 {
124 va_list ap;
125 struct devdesc *dev;
126
127 va_start(ap, f);
128 dev = va_arg(ap, struct devdesc *);
129 va_end(ap);
130
131 if (dev->d_unit != 0)
132 return (ENXIO);
133
134 return (0);
135 }
136
137 static int
md_close(struct open_file * f)138 md_close(struct open_file *f)
139 {
140 struct devdesc *dev;
141
142 dev = (struct devdesc *)(f->f_devdata);
143 return ((dev->d_unit != 0) ? ENXIO : 0);
144 }
145
146 static int
md_print(int verbose)147 md_print(int verbose)
148 {
149
150 printf("%s devices:", md_dev.dv_name);
151 if (pager_output("\n") != 0)
152 return (1);
153
154 printf("MD (%u bytes)", MD_IMAGE_SIZE);
155 return (pager_output("\n"));
156 }
157