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