add roms/pcbios
[armpft.git] / block / bochs.c
blobbac81c42b7922378c1669bcb476a4211bcbb0f45
1 /*
2 * Block driver for the various disk image formats used by Bochs
3 * Currently only for "growing" type in read-only mode
5 * Copyright (c) 2005 Alex Beregszaszi
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23 * THE SOFTWARE.
25 #include "qemu-common.h"
26 #include "block_int.h"
27 #include "module.h"
29 /**************************************************************/
31 #define HEADER_MAGIC "Bochs Virtual HD Image"
32 #define HEADER_VERSION 0x00020000
33 #define HEADER_V1 0x00010000
34 #define HEADER_SIZE 512
36 #define REDOLOG_TYPE "Redolog"
37 #define GROWING_TYPE "Growing"
39 // not allocated: 0xffffffff
41 // always little-endian
42 struct bochs_header_v1 {
43 char magic[32]; // "Bochs Virtual HD Image"
44 char type[16]; // "Redolog"
45 char subtype[16]; // "Undoable" / "Volatile" / "Growing"
46 uint32_t version;
47 uint32_t header; // size of header
49 union {
50 struct {
51 uint32_t catalog; // num of entries
52 uint32_t bitmap; // bitmap size
53 uint32_t extent; // extent size
54 uint64_t disk; // disk size
55 char padding[HEADER_SIZE - 64 - 8 - 20];
56 } redolog;
57 char padding[HEADER_SIZE - 64 - 8];
58 } extra;
61 // always little-endian
62 struct bochs_header {
63 char magic[32]; // "Bochs Virtual HD Image"
64 char type[16]; // "Redolog"
65 char subtype[16]; // "Undoable" / "Volatile" / "Growing"
66 uint32_t version;
67 uint32_t header; // size of header
69 union {
70 struct {
71 uint32_t catalog; // num of entries
72 uint32_t bitmap; // bitmap size
73 uint32_t extent; // extent size
74 uint32_t reserved; // for ???
75 uint64_t disk; // disk size
76 char padding[HEADER_SIZE - 64 - 8 - 24];
77 } redolog;
78 char padding[HEADER_SIZE - 64 - 8];
79 } extra;
82 typedef struct BDRVBochsState {
83 int fd;
85 uint32_t *catalog_bitmap;
86 int catalog_size;
88 int data_offset;
90 int bitmap_blocks;
91 int extent_blocks;
92 int extent_size;
93 } BDRVBochsState;
95 static int bochs_probe(const uint8_t *buf, int buf_size, const char *filename)
97 const struct bochs_header *bochs = (const void *)buf;
99 if (buf_size < HEADER_SIZE)
100 return 0;
102 if (!strcmp(bochs->magic, HEADER_MAGIC) &&
103 !strcmp(bochs->type, REDOLOG_TYPE) &&
104 !strcmp(bochs->subtype, GROWING_TYPE) &&
105 ((le32_to_cpu(bochs->version) == HEADER_VERSION) ||
106 (le32_to_cpu(bochs->version) == HEADER_V1)))
107 return 100;
109 return 0;
112 static int bochs_open(BlockDriverState *bs, const char *filename, int flags)
114 BDRVBochsState *s = bs->opaque;
115 int fd, i;
116 struct bochs_header bochs;
117 struct bochs_header_v1 header_v1;
119 fd = open(filename, O_RDWR | O_BINARY);
120 if (fd < 0) {
121 fd = open(filename, O_RDONLY | O_BINARY);
122 if (fd < 0)
123 return -1;
126 bs->read_only = 1; // no write support yet
128 s->fd = fd;
130 if (read(fd, &bochs, sizeof(bochs)) != sizeof(bochs)) {
131 goto fail;
134 if (strcmp(bochs.magic, HEADER_MAGIC) ||
135 strcmp(bochs.type, REDOLOG_TYPE) ||
136 strcmp(bochs.subtype, GROWING_TYPE) ||
137 ((le32_to_cpu(bochs.version) != HEADER_VERSION) &&
138 (le32_to_cpu(bochs.version) != HEADER_V1))) {
139 goto fail;
142 if (le32_to_cpu(bochs.version) == HEADER_V1) {
143 memcpy(&header_v1, &bochs, sizeof(bochs));
144 bs->total_sectors = le64_to_cpu(header_v1.extra.redolog.disk) / 512;
145 } else {
146 bs->total_sectors = le64_to_cpu(bochs.extra.redolog.disk) / 512;
149 lseek(s->fd, le32_to_cpu(bochs.header), SEEK_SET);
151 s->catalog_size = le32_to_cpu(bochs.extra.redolog.catalog);
152 s->catalog_bitmap = qemu_malloc(s->catalog_size * 4);
153 if (read(s->fd, s->catalog_bitmap, s->catalog_size * 4) !=
154 s->catalog_size * 4)
155 goto fail;
156 for (i = 0; i < s->catalog_size; i++)
157 le32_to_cpus(&s->catalog_bitmap[i]);
159 s->data_offset = le32_to_cpu(bochs.header) + (s->catalog_size * 4);
161 s->bitmap_blocks = 1 + (le32_to_cpu(bochs.extra.redolog.bitmap) - 1) / 512;
162 s->extent_blocks = 1 + (le32_to_cpu(bochs.extra.redolog.extent) - 1) / 512;
164 s->extent_size = le32_to_cpu(bochs.extra.redolog.extent);
166 return 0;
167 fail:
168 close(fd);
169 return -1;
172 static inline int seek_to_sector(BlockDriverState *bs, int64_t sector_num)
174 BDRVBochsState *s = bs->opaque;
175 int64_t offset = sector_num * 512;
176 int64_t extent_index, extent_offset, bitmap_offset, block_offset;
177 char bitmap_entry;
179 // seek to sector
180 extent_index = offset / s->extent_size;
181 extent_offset = (offset % s->extent_size) / 512;
183 if (s->catalog_bitmap[extent_index] == 0xffffffff)
185 // fprintf(stderr, "page not allocated [%x - %x:%x]\n",
186 // sector_num, extent_index, extent_offset);
187 return -1; // not allocated
190 bitmap_offset = s->data_offset + (512 * s->catalog_bitmap[extent_index] *
191 (s->extent_blocks + s->bitmap_blocks));
192 block_offset = bitmap_offset + (512 * (s->bitmap_blocks + extent_offset));
194 // fprintf(stderr, "sect: %x [ext i: %x o: %x] -> %x bitmap: %x block: %x\n",
195 // sector_num, extent_index, extent_offset,
196 // le32_to_cpu(s->catalog_bitmap[extent_index]),
197 // bitmap_offset, block_offset);
199 // read in bitmap for current extent
200 lseek(s->fd, bitmap_offset + (extent_offset / 8), SEEK_SET);
202 read(s->fd, &bitmap_entry, 1);
204 if (!((bitmap_entry >> (extent_offset % 8)) & 1))
206 // fprintf(stderr, "sector (%x) in bitmap not allocated\n",
207 // sector_num);
208 return -1; // not allocated
211 lseek(s->fd, block_offset, SEEK_SET);
213 return 0;
216 static int bochs_read(BlockDriverState *bs, int64_t sector_num,
217 uint8_t *buf, int nb_sectors)
219 BDRVBochsState *s = bs->opaque;
220 int ret;
222 while (nb_sectors > 0) {
223 if (!seek_to_sector(bs, sector_num))
225 ret = read(s->fd, buf, 512);
226 if (ret != 512)
227 return -1;
229 else
230 memset(buf, 0, 512);
231 nb_sectors--;
232 sector_num++;
233 buf += 512;
235 return 0;
238 static void bochs_close(BlockDriverState *bs)
240 BDRVBochsState *s = bs->opaque;
241 qemu_free(s->catalog_bitmap);
242 close(s->fd);
245 static BlockDriver bdrv_bochs = {
246 .format_name = "bochs",
247 .instance_size = sizeof(BDRVBochsState),
248 .bdrv_probe = bochs_probe,
249 .bdrv_open = bochs_open,
250 .bdrv_read = bochs_read,
251 .bdrv_close = bochs_close,
254 static void bdrv_bochs_init(void)
256 bdrv_register(&bdrv_bochs);
259 block_init(bdrv_bochs_init);