2 * Block driver for Conectix/Microsoft Virtual PC images
4 * Copyright (c) 2005 Alex Beregszaszi
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24 #include "qemu-common.h"
25 #include "block_int.h"
27 /**************************************************************/
29 #define HEADER_SIZE 512
35 char creator[8]; // "conectix
37 uint32_t unk2; // always zero?
38 uint32_t subheader_offset;
39 uint32_t unk3; // some size?
40 char creator_app[4]; // "vpc "
43 char guest[4]; // "Wi2k"
45 uint8_t vnet_id[16]; // virtual network id, purpose unknown
46 // next 16 longs are used, but dunno the purpose
47 // next 6 longs unknown, following 7 long maybe a serial
50 struct vhd_dyndisk_header {
51 char magic[8]; // "cxsparse"
52 uint32_t unk1[2]; // all bits set
53 uint32_t unk2; // always zero?
54 uint32_t pagetable_offset;
56 uint32_t pagetable_entries; // 32bit/entry
57 uint32_t pageentry_size; // 512*8*512
61 typedef struct BDRVVPCState {
64 int pagetable_entries;
67 uint32_t pageentry_size;
69 uint8_t *pageentry_u8;
70 uint32_t *pageentry_u32;
71 uint16_t *pageentry_u16;
77 static int vpc_probe(const uint8_t *buf, int buf_size, const char *filename)
79 if (buf_size >= 8 && !strncmp((char *)buf, "conectix", 8))
84 static int vpc_open(BlockDriverState *bs, const char *filename, int flags)
86 BDRVVPCState *s = bs->opaque;
88 struct vhd_footer* footer;
89 struct vhd_dyndisk_header* dyndisk_header;
90 uint8_t buf[HEADER_SIZE];
92 fd = open(filename, O_RDONLY | O_BINARY);
96 bs->read_only = 1; // no write support yet
100 if (read(fd, buf, HEADER_SIZE) != HEADER_SIZE)
103 footer = (struct vhd_footer*) buf;
104 if (strncmp(footer->creator, "conectix", 8))
107 lseek(s->fd, be32_to_cpu(footer->subheader_offset), SEEK_SET);
108 if (read(fd, buf, HEADER_SIZE) != HEADER_SIZE)
112 dyndisk_header = (struct vhd_dyndisk_header*) buf;
114 if (strncmp(dyndisk_header->magic, "cxsparse", 8))
117 bs->total_sectors = ((uint64_t)be32_to_cpu(dyndisk_header->pagetable_entries) *
118 be32_to_cpu(dyndisk_header->pageentry_size)) / 512;
120 lseek(s->fd, be32_to_cpu(dyndisk_header->pagetable_offset), SEEK_SET);
122 s->pagetable_entries = be32_to_cpu(dyndisk_header->pagetable_entries);
123 s->pagetable = qemu_malloc(s->pagetable_entries * 4);
126 if (read(s->fd, s->pagetable, s->pagetable_entries * 4) !=
127 s->pagetable_entries * 4)
129 for (i = 0; i < s->pagetable_entries; i++)
130 be32_to_cpus(&s->pagetable[i]);
132 s->pageentry_size = be32_to_cpu(dyndisk_header->pageentry_size);
134 s->pageentry_u8 = qemu_malloc(512);
135 if (!s->pageentry_u8)
137 s->pageentry_u32 = s->pageentry_u8;
138 s->pageentry_u16 = s->pageentry_u8;
139 s->last_pagetable = -1;
148 static inline int seek_to_sector(BlockDriverState *bs, int64_t sector_num)
150 BDRVVPCState *s = bs->opaque;
151 uint64_t offset = sector_num * 512;
152 uint64_t bitmap_offset, block_offset;
153 uint32_t pagetable_index, pageentry_index;
155 pagetable_index = offset / s->pageentry_size;
156 pageentry_index = (offset % s->pageentry_size) / 512;
158 if (pagetable_index > s->pagetable_entries || s->pagetable[pagetable_index] == 0xffffffff)
159 return -1; // not allocated
161 bitmap_offset = 512 * s->pagetable[pagetable_index];
162 block_offset = bitmap_offset + 512 + (512 * pageentry_index);
164 // printf("sector: %" PRIx64 ", index: %x, offset: %x, bioff: %" PRIx64 ", bloff: %" PRIx64 "\n",
165 // sector_num, pagetable_index, pageentry_index,
166 // bitmap_offset, block_offset);
168 // disabled by reason
171 if (bitmap_offset != s->last_bitmap)
173 lseek(s->fd, bitmap_offset, SEEK_SET);
175 s->last_bitmap = bitmap_offset;
177 // Scary! Bitmap is stored as big endian 32bit entries,
178 // while we used to look it up byte by byte
179 read(s->fd, s->pageentry_u8, 512);
180 for (i = 0; i < 128; i++)
181 be32_to_cpus(&s->pageentry_u32[i]);
184 if ((s->pageentry_u8[pageentry_index / 8] >> (pageentry_index % 8)) & 1)
187 lseek(s->fd, bitmap_offset + (pageentry_index / 8), SEEK_SET);
189 read(s->fd, &bitmap_entry, 1);
191 if ((bitmap_entry >> (pageentry_index % 8)) & 1)
192 return -1; // not allocated
195 lseek(s->fd, block_offset, SEEK_SET);
200 static int vpc_read(BlockDriverState *bs, int64_t sector_num,
201 uint8_t *buf, int nb_sectors)
203 BDRVVPCState *s = bs->opaque;
206 while (nb_sectors > 0) {
207 if (!seek_to_sector(bs, sector_num))
209 ret = read(s->fd, buf, 512);
222 static void vpc_close(BlockDriverState *bs)
224 BDRVVPCState *s = bs->opaque;
225 qemu_free(s->pagetable);
227 qemu_free(s->pageentry_u8);
232 BlockDriver bdrv_vpc = {
234 sizeof(BDRVVPCState),