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ba41f4cbff
Bochs/bochs/iodev/vvfat.cc
Volker Ruppert ba41f4cbff - set cluster size depending on disk size (FAT32 support not complete) 
- several fixes related to configurable geometry (some more tests required)
- skip MBR and boot sector image files when reading directory (still unused)
- support overriding cylinder value with 0 in the command line
- don't return failure value when reading unused sectors
- increment buffer pointer when reading more than one sector
2010-12-24 20:47:22 +00:00

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/////////////////////////////////////////////////////////////////////////
// $Id: vvfat.cc,v 1.2 2010-12-24 20:47:22 vruppert Exp $
/////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2010 The Bochs Project
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
/////////////////////////////////////////////////////////////////////////
// Virtual VFAT image support (shadows a local directory)
// ported from the Qemu block driver by Johannes E. Schindelin
// ADDITIONS:
// - win32 specific directory functions (required for MSVC)
// - configurable disk geometry (not yet complete)
// TODO:
// - write support
// - FAT32 support
// - read MBR and boot sector from file
// Define BX_PLUGGABLE in files that can be compiled into plugins. For
// platforms that require a special tag on exported symbols, BX_PLUGGABLE
// is used to know when we are exporting symbols and when we are importing.
#define BX_PLUGGABLE
#ifndef WIN32
#include <dirent.h>
#endif
#define NO_DEVICE_INCLUDES
#include "iodev.h"
#include "hdimage.h"
#include "vvfat.h"
#define LOG_THIS bx_devices.pluginHardDrive->
#define VVFAT_MBR "vvfat_mbr.bin"
#define VVFAT_BOOT "vvfat_boot.bin"
#if defined (BX_LITTLE_ENDIAN)
#define htod16(val) (val)
#else
#define htod16(val) ( (((val)&0xff00)>>8) | (((val)&0xff)<<8) )
#endif
// dynamic array functions
static inline void array_init(array_t* array,unsigned int item_size)
{
array->pointer = NULL;
array->size = 0;
array->next = 0;
array->item_size = item_size;
}
static inline void array_free(array_t* array)
{
if (array->pointer)
free(array->pointer);
array->size=array->next = 0;
}
// does not automatically grow
static inline void* array_get(array_t* array,unsigned int index)
{
assert(index < array->next);
return array->pointer + index * array->item_size;
}
static inline int array_ensure_allocated(array_t* array, int index)
{
if ((index + 1) * array->item_size > array->size) {
int new_size = (index + 32) * array->item_size;
array->pointer = (char*)realloc(array->pointer, new_size);
if (!array->pointer)
return -1;
array->size = new_size;
array->next = index + 1;
}
return 0;
}
static inline void* array_get_next(array_t* array)
{
unsigned int next = array->next;
void* result;
if (array_ensure_allocated(array, next) < 0)
return NULL;
array->next = next + 1;
result = array_get(array, next);
return result;
}
static inline void* array_insert(array_t* array,unsigned int index,unsigned int count)
{
if ((array->next+count)*array->item_size > array->size) {
int increment = count*array->item_size;
array->pointer = (char*)realloc(array->pointer, array->size+increment);
if (!array->pointer)
return NULL;
array->size += increment;
}
memmove(array->pointer+(index+count)*array->item_size,
array->pointer+index*array->item_size,
(array->next-index)*array->item_size);
array->next += count;
return array->pointer+index*array->item_size;
}
/* this performs a "roll", so that the element which was at index_from becomes
* index_to, but the order of all other elements is preserved. */
static inline int array_roll(array_t* array, int index_to, int index_from, int count)
{
char* buf;
char* from;
char* to;
int is;
if (!array ||
(index_to < 0) || (index_to >= (int)array->next) ||
(index_from < 0 || (index_from >= (int)array->next)))
return -1;
if (index_to == index_from)
return 0;
is = array->item_size;
from = array->pointer+index_from*is;
to = array->pointer+index_to*is;
buf = (char*)malloc(is*count);
memcpy(buf, from, is*count);
if (index_to < index_from)
memmove(to+is*count, to, from-to);
else
memmove(from, from+is*count, to-from);
memcpy(to, buf, is*count);
free(buf);
return 0;
}
static inline int array_remove_slice(array_t* array,int index, int count)
{
assert(index >=0);
assert(count > 0);
assert(index + count <= (int)array->next);
if (array_roll(array,array->next-1,index,count))
return -1;
array->next -= count;
return 0;
}
static int array_remove(array_t* array,int index)
{
return array_remove_slice(array, index, 1);
}
// return the index for a given member
static int array_index(array_t* array, void* pointer)
{
size_t offset = (char*)pointer - array->pointer;
assert((offset % array->item_size) == 0);
assert(offset/array->item_size < array->next);
return offset/array->item_size;
}
#if defined(_MSC_VER)
#pragma pack(push, 1)
#elif defined(__MWERKS__) && defined(macintosh)
#pragma options align=packed
#endif
typedef
#if defined(_MSC_VER) && (_MSC_VER>=1300)
__declspec(align(1))
#endif
struct bootsector_t {
Bit8u jump[3];
Bit8u name[8];
Bit16u sector_size;
Bit8u sectors_per_cluster;
Bit16u reserved_sectors;
Bit8u number_of_fats;
Bit16u root_entries;
Bit16u total_sectors16;
Bit8u media_type;
Bit16u sectors_per_fat;
Bit16u sectors_per_track;
Bit16u number_of_heads;
Bit32u hidden_sectors;
Bit32u total_sectors;
union {
#if defined(_MSC_VER) && (_MSC_VER>=1300)
__declspec(align(1))
#endif
struct {
Bit8u drive_number;
Bit8u current_head;
Bit8u signature;
Bit32u id;
Bit8u volume_label[11];
}
#if !defined(_MSC_VER)
GCC_ATTRIBUTE((packed))
#endif
fat16;
#if defined(_MSC_VER) && (_MSC_VER>=1300)
__declspec(align(1))
#endif
struct {
Bit32u sectors_per_fat;
Bit16u flags;
Bit8u major, minor;
Bit32u first_cluster_of_root_directory;
Bit16u info_sector;
Bit16u backup_boot_sector;
Bit16u ignored;
}
#if !defined(_MSC_VER)
GCC_ATTRIBUTE((packed))
#endif
fat32;
} u;
Bit8u fat_type[8];
Bit8u ignored[0x1c0];
Bit8u magic[2];
}
#if !defined(_MSC_VER)
GCC_ATTRIBUTE((packed))
#endif
bootsector_t;
typedef
#if defined(_MSC_VER) && (_MSC_VER>=1300)
__declspec(align(1))
#endif
struct partition_t {
Bit8u attributes; /* 0x80 = bootable */
mbr_chs_t start_CHS;
Bit8u fs_type; /* 0x1 = FAT12, 0x6 = FAT16, 0xe = FAT16_LBA, 0xb = FAT32, 0xc = FAT32_LBA */
mbr_chs_t end_CHS;
Bit32u start_sector_long;
Bit32u length_sector_long;
}
#if !defined(_MSC_VER)
GCC_ATTRIBUTE((packed))
#endif
partition_t;
typedef
#if defined(_MSC_VER) && (_MSC_VER>=1300)
__declspec(align(1))
#endif
struct mbr_t {
Bit8u ignored[0x1b8];
Bit32u nt_id;
Bit8u ignored2[2];
partition_t partition[4];
Bit8u magic[2];
}
#if !defined(_MSC_VER)
GCC_ATTRIBUTE((packed))
#endif
mbr_t;
#if defined(_MSC_VER)
#pragma pack(pop)
#elif defined(__MWERKS__) && defined(macintosh)
#pragma options align=reset
#endif
vvfat_image_t::vvfat_image_t()
{
first_sectors = new Bit8u[0x8000];
}
vvfat_image_t::~vvfat_image_t()
{
delete [] first_sectors;
}
bx_bool vvfat_image_t::sector2CHS(Bit32u spos, mbr_chs_t *chs)
{
Bit32u head, sector;
sector = spos % sectors;
spos /= sectors;
head = spos % heads;
spos /= heads;
if (spos >= cylinders) {
/* Overflow,
it happens if 32bit sector positions are used, while CHS is only 24bit.
Windows/Dos is said to take 1023/255/63 as nonrepresentable CHS */
chs->head = 0xff;
chs->sector = 0xff;
chs->cylinder = 0xff;
return 1;
}
chs->head = (Bit8u)head;
chs->sector = (Bit8u)((sector+1) | ((spos >> 8) << 6));
chs->cylinder = (Bit8u)spos;
return 0;
}
void vvfat_image_t::init_mbr(void)
{
mbr_t* real_mbr = (mbr_t*)first_sectors;
partition_t* partition = &(real_mbr->partition[0]);
bx_bool lba;
memset(first_sectors, 0, 0x0200);
// Win NT Disk Signature
real_mbr->nt_id = htod32(0xbe1afdfa);
partition->attributes = 0x80; // bootable
// LBA is used when partition is outside the CHS geometry
lba = sector2CHS(n_first_sectors - 1, &partition->start_CHS);
lba |= sector2CHS(sector_count, &partition->end_CHS);
// LBA partitions are identified only by start/length_sector_long not by CHS
partition->start_sector_long = htod32(n_first_sectors - 1);
partition->length_sector_long = htod32(sector_count - n_first_sectors + 1);
/* FAT12/FAT16/FAT32 */
/* DOS uses different types when partition is LBA,
probably to prevent older versions from using CHS on them */
partition->fs_type = fat_type==12 ? 0x1:
fat_type==16 ? (lba?0xe:0x06):
/*fat_tyoe==32*/ (lba?0xc:0x0b);
real_mbr->magic[0] = 0x55;
real_mbr->magic[1] = 0xaa;
}
// dest is assumed to hold 258 bytes, and pads with 0xffff up to next multiple of 26
static inline int short2long_name(char* dest,const char* src)
{
int i;
int len;
for (i = 0; (i < 129) && src[i]; i++) {
dest[2*i] = src[i];
dest[2*i+1] = 0;
}
len = 2 * i;
dest[2*i] = dest[2*i+1] = 0;
for (i = 2 * i + 2; (i % 26); i++)
dest[i] = (char)0xff;
return len;
}
direntry_t* vvfat_image_t::create_long_filename(const char* filename)
{
char buffer[258];
int length = short2long_name(buffer, filename),
number_of_entries = (length+25) / 26, i;
direntry_t* entry;
for (i = 0; i < number_of_entries; i++) {
entry = (direntry_t*)array_get_next(&directory);
entry->attributes = 0xf;
entry->reserved[0] = 0;
entry->begin = 0;
entry->name[0] = (number_of_entries - i) | (i==0 ? 0x40:0);
}
for (i = 0; i < 26 * number_of_entries; i++) {
int offset = (i % 26);
if (offset < 10) offset = 1 + offset;
else if (offset < 22) offset = 14 + offset - 10;
else offset = 28 + offset - 22;
entry = (direntry_t*)array_get(&directory, directory.next - 1 - (i / 26));
entry->name[offset] = buffer[i];
}
return (direntry_t*)array_get(&directory, directory.next-number_of_entries);
}
static char is_long_name(const direntry_t* direntry)
{
return direntry->attributes == 0xf;
}
static void set_begin_of_direntry(direntry_t* direntry, Bit32u begin)
{
direntry->begin = htod16(begin & 0xffff);
direntry->begin_hi = htod16((begin >> 16) & 0xffff);
}
static inline Bit8u fat_chksum(const direntry_t* entry)
{
Bit8u chksum = 0;
int i;
for (i = 0; i < 11; i++) {
unsigned char c;
c = (i < 8) ? entry->name[i] : entry->extension[i-8];
chksum = (((chksum & 0xfe) >> 1) | ((chksum & 0x01) ? 0x80:0)) + c;
}
return chksum;
}
// if return_time==0, this returns the fat_date, else the fat_time
#ifndef WIN32
static Bit16u fat_datetime(time_t time, int return_time)
{
struct tm* t;
struct tm t1;
t = &t1;
localtime_r(&time, t);
if (return_time)
return htod16((t->tm_sec/2) | (t->tm_min<<5) | (t->tm_hour<<11));
return htod16((t->tm_mday) | ((t->tm_mon+1)<<5) | ((t->tm_year-80)<<9));
}
#else
static Bit16u fat_datetime(FILETIME time, int return_time)
{
FILETIME localtime;
SYSTEMTIME systime;
FileTimeToLocalFileTime(&time, &localtime);
FileTimeToSystemTime(&localtime, &systime);
if (return_time)
return htod16((systime.wSecond/2) | (systime.wMinute<<5) | (systime.wHour<<11));
return htod16((systime.wDay) | (systime.wMonth<<5) | ((systime.wYear-1980)<<9));
}
#endif
void vvfat_image_t::fat_set(unsigned int cluster, Bit32u value)
{
if (fat_type == 32) {
Bit32u* entry = (Bit32u*)array_get(&fat, cluster);
*entry = htod32(value);
} else if (fat_type == 16) {
Bit16u* entry = (Bit16u*)array_get(&fat, cluster);
*entry = htod16(value & 0xffff);
} else {
int offset = (cluster * 3 / 2);
Bit8u* p = (Bit8u*)array_get(&fat, offset);
switch (cluster & 1) {
case 0:
p[0] = value & 0xff;
p[1] = (p[1] & 0xf0) | ((value>>8) & 0xf);
break;
case 1:
p[0] = (p[0]&0xf) | ((value&0xf)<<4);
p[1] = (value>>4);
break;
}
}
}
void vvfat_image_t::init_fat(void)
{
if (fat_type == 12) {
array_init(&fat, 1);
array_ensure_allocated(&fat, sectors_per_fat * 0x200 * 3 / 2 - 1);
} else {
array_init(&fat, (fat_type==32) ? 4:2);
array_ensure_allocated(&fat, sectors_per_fat * 0x200 / fat.item_size - 1);
}
memset(fat.pointer, 0, fat.size);
switch (fat_type) {
case 12: max_fat_value = 0xfff; break;
case 16: max_fat_value = 0xffff; break;
case 32: max_fat_value = 0x0fffffff; break;
default: max_fat_value = 0; /* error... */
}
}
// TODO: in create_short_filename, 0xe5->0x05 is not yet handled!
// TODO: in parse_short_filename, 0x05->0xe5 is not yet handled!
direntry_t* vvfat_image_t::create_short_and_long_name(
unsigned int directory_start, const char* filename, int is_dot)
{
int i, j, long_index = directory.next;
direntry_t* entry = NULL;
direntry_t* entry_long = NULL;
if (is_dot) {
entry = (direntry_t*)array_get_next(&directory);
memset(entry->name,0x20,11);
memcpy(entry->name,filename,strlen(filename));
return entry;
}
entry_long = create_long_filename(filename);
i = strlen(filename);
for (j = i - 1; j>0 && filename[j]!='.';j--);
if (j > 0)
i = (j > 8 ? 8 : j);
else if (i > 8)
i = 8;
entry = (direntry_t*)array_get_next(&directory);
memset(entry->name, 0x20, 11);
memcpy(entry->name, filename, i);
if (j > 0)
for (i = 0; i < 3 && filename[j+1+i]; i++)
entry->extension[i] = filename[j+1+i];
// upcase & remove unwanted characters
for (i=10;i>=0;i--) {
if (i==10 || i==7) for (;i>0 && entry->name[i]==' ';i--);
if (entry->name[i]<=' ' || entry->name[i]>0x7f
|| strchr(".*?<>|\":/\\[];,+='",entry->name[i]))
entry->name[i]='_';
else if (entry->name[i]>='a' && entry->name[i]<='z')
entry->name[i]+='A'-'a';
}
// mangle duplicates
while (1) {
direntry_t* entry1 = (direntry_t*)array_get(&directory, directory_start);
int j;
for (;entry1<entry;entry1++)
if (!is_long_name(entry1) && !memcmp(entry1->name,entry->name,11))
break; // found dupe
if (entry1==entry) // no dupe found
break;
// use all 8 characters of name
if (entry->name[7]==' ') {
int j;
for(j=6;j>0 && entry->name[j]==' ';j--)
entry->name[j]='~';
}
// increment number
for (j=7;j>0 && entry->name[j]=='9';j--)
entry->name[j]='0';
if (j > 0) {
if (entry->name[j]<'0' || entry->name[j]>'9')
entry->name[j]='0';
else
entry->name[j]++;
}
}
// calculate checksum; propagate to long name
if (entry_long) {
Bit8u chksum = fat_chksum(entry);
// calculate anew, because realloc could have taken place
entry_long = (direntry_t*)array_get(&directory, long_index);
while (entry_long<entry && is_long_name(entry_long)) {
entry_long->reserved[1]=chksum;
entry_long++;
}
}
return entry;
}
/*
* Read a directory. (the index of the corresponding mapping must be passed).
*/
int vvfat_image_t::read_directory(int mapping_index)
{
mapping_t* mapping = (mapping_t*)array_get(&this->mapping, mapping_index);
direntry_t* direntry;
const char* dirname = mapping->path;
int first_cluster = mapping->begin;
int parent_index = mapping->info.dir.parent_mapping_index;
mapping_t* parent_mapping = (mapping_t*)
(parent_index >= 0 ? array_get(&this->mapping, parent_index) : NULL);
int first_cluster_of_parent = parent_mapping ? (int)parent_mapping->begin : -1;
#ifndef WIN32
DIR* dir = opendir(dirname);
struct dirent* entry;
int i;
assert(mapping->mode & MODE_DIRECTORY);
if (!dir) {
mapping->end = mapping->begin;
return -1;
}
i = mapping->info.dir.first_dir_index =
first_cluster == 0 ? 0 : directory.next;
// actually read the directory, and allocate the mappings
while ((entry=readdir(dir))) {
unsigned int length = strlen(dirname) + 2 + strlen(entry->d_name);
char* buffer;
direntry_t* direntry;
struct stat st;
bx_bool is_dot = !strcmp(entry->d_name, ".");
bx_bool is_dotdot = !strcmp(entry->d_name, "..");
if (first_cluster == 0 && (is_dotdot || is_dot))
continue;
buffer = (char*)malloc(length);
snprintf(buffer,length,"%s/%s",dirname,entry->d_name);
if (stat(buffer, &st) < 0) {
free(buffer);
continue;
}
bx_bool is_mbr_file = !strcmp(entry->d_name, VVFAT_MBR);
bx_bool is_boot_file = !strcmp(entry->d_name, VVFAT_BOOT);
if (first_cluster == 0 && (is_mbr_file || is_boot_file) && (st.st_size == 512)) {
free(buffer);
continue;
}
// create directory entry for this file
direntry = create_short_and_long_name(i, entry->d_name, is_dot || is_dotdot);
direntry->attributes = (S_ISDIR(st.st_mode) ? 0x10 : 0x20);
direntry->reserved[0] = direntry->reserved[1]=0;
direntry->ctime = fat_datetime(st.st_ctime, 1);
direntry->cdate = fat_datetime(st.st_ctime, 0);
direntry->adate = fat_datetime(st.st_atime, 0);
direntry->begin_hi = 0;
direntry->mtime = fat_datetime(st.st_mtime, 1);
direntry->mdate = fat_datetime(st.st_mtime, 0);
if (is_dotdot)
set_begin_of_direntry(direntry, first_cluster_of_parent);
else if (is_dot)
set_begin_of_direntry(direntry, first_cluster);
else
direntry->begin = 0; // do that later
if (st.st_size > 0x7fffffff) {
BX_ERROR(("File %s is larger than 2GB", buffer));
free(buffer);
return -2;
}
direntry->size = htod32(S_ISDIR(st.st_mode) ? 0:st.st_size);
// create mapping for this file
if (!is_dot && !is_dotdot && (S_ISDIR(st.st_mode) || st.st_size)) {
current_mapping = (mapping_t*)array_get_next(&this->mapping);
current_mapping->begin = 0;
current_mapping->end = st.st_size;
/*
* we get the direntry of the most recent direntry, which
* contains the short name and all the relevant information.
*/
current_mapping->dir_index = directory.next-1;
current_mapping->first_mapping_index = -1;
if (S_ISDIR(st.st_mode)) {
current_mapping->mode = MODE_DIRECTORY;
current_mapping->info.dir.parent_mapping_index =
mapping_index;
} else {
current_mapping->mode = MODE_UNDEFINED;
current_mapping->info.file.offset = 0;
}
current_mapping->path = buffer;
current_mapping->read_only =
(st.st_mode & (S_IWUSR | S_IWGRP | S_IWOTH)) == 0;
}
}
closedir(dir);
#else
WIN32_FIND_DATA finddata;
char filter[MAX_PATH];
wsprintf(filter, "%s\\*.*", dirname);
HANDLE hFind = FindFirstFile(filter, &finddata);
int i;
assert(mapping->mode & MODE_DIRECTORY);
if (hFind == INVALID_HANDLE_VALUE) {
mapping->end = mapping->begin;
return -1;
}
i = mapping->info.dir.first_dir_index =
first_cluster == 0 ? 0 : directory.next;
// actually read the directory, and allocate the mappings
do {
unsigned int length = lstrlen(dirname) + 2 + lstrlen(finddata.cFileName);
char* buffer;
direntry_t* direntry;
bx_bool is_dot = !lstrcmp(finddata.cFileName, ".");
bx_bool is_dotdot = !lstrcmp(finddata.cFileName, "..");
if (first_cluster == 0 && (is_dotdot || is_dot))
continue;
bx_bool is_mbr_file = !lstrcmp(finddata.cFileName, VVFAT_MBR);
bx_bool is_boot_file = !lstrcmp(finddata.cFileName, VVFAT_BOOT);
if (first_cluster == 0 && (is_mbr_file || is_boot_file) && (finddata.nFileSizeLow == 512))
continue;
buffer = (char*)malloc(length);
snprintf(buffer, length, "%s/%s", dirname, finddata.cFileName);
// create directory entry for this file
direntry = create_short_and_long_name(i, finddata.cFileName, is_dot || is_dotdot);
direntry->attributes = ((finddata.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) ? 0x10 : 0x20);
direntry->reserved[0] = direntry->reserved[1]=0;
direntry->ctime = fat_datetime(finddata.ftCreationTime, 1);
direntry->cdate = fat_datetime(finddata.ftCreationTime, 0);
direntry->adate = fat_datetime(finddata.ftLastAccessTime, 0);
direntry->begin_hi = 0;
direntry->mtime = fat_datetime(finddata.ftLastWriteTime, 1);
direntry->mdate = fat_datetime(finddata.ftLastWriteTime, 0);
if (is_dotdot)
set_begin_of_direntry(direntry, first_cluster_of_parent);
else if (is_dot)
set_begin_of_direntry(direntry, first_cluster);
else
direntry->begin = 0; // do that later
if (finddata.nFileSizeLow > 0x7fffffff) {
BX_ERROR(("File %s is larger than 2GB", buffer));
free(buffer);
return -2;
}
direntry->size = htod32((finddata.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) ? 0:finddata.nFileSizeLow);
// create mapping for this file
if (!is_dot && !is_dotdot && ((finddata.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) || finddata.nFileSizeLow)) {
current_mapping = (mapping_t*)array_get_next(&this->mapping);
current_mapping->begin = 0;
current_mapping->end = finddata.nFileSizeLow;
/*
* we get the direntry of the most recent direntry, which
* contains the short name and all the relevant information.
*/
current_mapping->dir_index = directory.next-1;
current_mapping->first_mapping_index = -1;
if (finddata.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) {
current_mapping->mode = MODE_DIRECTORY;
current_mapping->info.dir.parent_mapping_index =
mapping_index;
} else {
current_mapping->mode = MODE_UNDEFINED;
current_mapping->info.file.offset = 0;
}
current_mapping->path=buffer;
current_mapping->read_only = (finddata.dwFileAttributes & FILE_ATTRIBUTE_READONLY);
}
} while (FindNextFile(hFind, &finddata));
FindClose(hFind);
#endif
// fill with zeroes up to the end of the cluster
while (directory.next % (0x10 * sectors_per_cluster)) {
direntry_t* direntry = (direntry_t*)array_get_next(&directory);
memset(direntry, 0, sizeof(direntry_t));
}
// TODO: if there are more entries, bootsector has to be adjusted!
#define ROOT_ENTRIES (0x02 * 0x10 * sectors_per_cluster)
if ((mapping_index == 0) && (directory.next < (unsigned int)ROOT_ENTRIES)) {
// root directory
int cur = directory.next;
array_ensure_allocated(&directory, ROOT_ENTRIES - 1);
memset(array_get(&directory, cur), 0,
(ROOT_ENTRIES - cur) * sizeof(direntry_t));
}
// reget the mapping, since s->mapping was possibly realloc()ed
mapping = (mapping_t*)array_get(&this->mapping, mapping_index);
first_cluster += (directory.next - mapping->info.dir.first_dir_index)
* 0x20 / cluster_size;
mapping->end = first_cluster;
direntry = (direntry_t*)array_get(&directory, mapping->dir_index);
set_begin_of_direntry(direntry, mapping->begin);
return 0;
}
Bit32u vvfat_image_t::sector2cluster(off_t sector_num)
{
return (Bit32u)(sector_num - faked_sectors) / sectors_per_cluster;
}
int vvfat_image_t::init_directories(const char* dirname)
{
bootsector_t* bootsector;
mapping_t* mapping;
unsigned int i;
unsigned int cluster;
char size_txt[8];
memset(&first_sectors[0], 0, 0x8000);
cluster_size = sectors_per_cluster * 0x200;
cluster_buffer = new Bit8u[cluster_size];
/*
* The formula: sc = spf+1+spf*spc*(512*8/fat_type),
* where sc is sector_count,
* spf is sectors_per_fat,
* spc is sectors_per_clusters, and
* fat_type = 12, 16 or 32.
*/
i = 1 + sectors_per_cluster * 0x200 * 8 / fat_type;
sectors_per_fat = (sector_count + i) / i; // round up
array_init(&this->mapping, sizeof(mapping_t));
array_init(&directory, sizeof(direntry_t));
/* add volume label */
{
direntry_t *entry = (direntry_t*)array_get_next(&directory);
entry->attributes = 0x28; // archive | volume label
memcpy(entry->name, "BOCHS VV", 8);
memcpy(entry->extension, "FAT", 3);
}
// Now build FAT, and write back information into directory
init_fat();
faked_sectors = n_first_sectors + sectors_per_fat * 2;
cluster_count = sector2cluster(sector_count);
mapping = (mapping_t*)array_get_next(&this->mapping);
mapping->begin = 0;
mapping->dir_index = 0;
mapping->info.dir.parent_mapping_index = -1;
mapping->first_mapping_index = -1;
mapping->path = strdup(dirname);
i = strlen(mapping->path);
if (i > 0 && mapping->path[i - 1] == '/')
mapping->path[i - 1] = '\0';
mapping->mode = MODE_DIRECTORY;
mapping->read_only = 0;
path = mapping->path;
for (i = 0, cluster = 0; i < this->mapping.next; i++) {
/* MS-DOS expects the FAT to be 0 for the root directory
* (except for the media byte). */
/* LATER TODO: still true for FAT32? */
int fix_fat = (i != 0);
mapping = (mapping_t*)array_get(&this->mapping, i);
if (mapping->mode & MODE_DIRECTORY) {
mapping->begin = cluster;
if (read_directory(i)) {
BX_ERROR(("Could not read directory %s", mapping->path));
return -1;
}
mapping = (mapping_t*)array_get(&this->mapping, i);
} else {
assert(mapping->mode == MODE_UNDEFINED);
mapping->mode = MODE_NORMAL;
mapping->begin = cluster;
if (mapping->end > 0) {
direntry_t* direntry = (direntry_t*)array_get(&directory, mapping->dir_index);
mapping->end = cluster + 1 + (mapping->end-1) / cluster_size;
set_begin_of_direntry(direntry, mapping->begin);
} else {
mapping->end = cluster + 1;
fix_fat = 0;
}
}
assert(mapping->begin < mapping->end);
/* next free cluster */
cluster = mapping->end;
if (cluster > cluster_count) {
sprintf(size_txt, "%dMB", sector_count * 512);
BX_ERROR(("Directory does not fit in FAT%d (capacity %s)",
fat_type,
(fat_type == 12) ? (sector_count == 2880) ? "1.44 MB":"2.88 MB"
: size_txt));
return -EINVAL;
}
// fix fat for entry
if (fix_fat) {
int j;
for (j = mapping->begin; j < (int)(mapping->end - 1); j++)
fat_set(j, j + 1);
fat_set(mapping->end - 1, max_fat_value);
}
}
mapping = (mapping_t*)array_get(&this->mapping, 0);
sectors_of_root_directory = mapping->end * sectors_per_cluster;
last_cluster_of_root_directory = mapping->end;
// the FAT signature
fat_set(0, max_fat_value);
fat_set(1, max_fat_value);
current_mapping = NULL;
bootsector = (bootsector_t*)(first_sectors+(n_first_sectors - 1) * 0x200);
bootsector->jump[0] = 0xeb;
bootsector->jump[1] = 0x3e;
bootsector->jump[2] = 0x90;
memcpy(bootsector->name,"BOCHS ", 8);
bootsector->sector_size = htod16(0x200);
bootsector->sectors_per_cluster = sectors_per_cluster;
bootsector->reserved_sectors = htod16(1);
bootsector->number_of_fats = 0x2;
bootsector->root_entries = htod16(sectors_of_root_directory * 0x10);
bootsector->total_sectors16 = (sector_count > 0xffff) ? 0:htod16(sector_count);
bootsector->media_type = ((fat_type != 12) ? 0xf8:(sector_count==5760) ? 0xf9:0xf8);
fat.pointer[0] = bootsector->media_type;
bootsector->sectors_per_fat = htod16(sectors_per_fat);
bootsector->sectors_per_track = htod16(sectors);
bootsector->number_of_heads = htod16(heads);
bootsector->hidden_sectors = htod32(n_first_sectors - 1);
bootsector->total_sectors = htod32((sector_count > 0xffff) ? sector_count:0);
// LATER TODO: if FAT32, this is wrong
bootsector->u.fat16.drive_number = (fat_type == 12) ? 0:0x80; // assume this is hda (TODO)
bootsector->u.fat16.current_head = 0;
bootsector->u.fat16.signature = 0x29;
bootsector->u.fat16.id = htod32(0xfabe1afd);
memcpy(bootsector->u.fat16.volume_label, "BOCHS VVFAT", 11);
memcpy(bootsector->fat_type, ((fat_type==12) ? "FAT12 ":(fat_type==16) ? "FAT16 ":"FAT32 "), 8);
bootsector->magic[0] = 0x55;
bootsector->magic[1] = 0xaa;
return 0;
}
int vvfat_image_t::open(const char* dirname)
{
Bit32u size_in_mb;
// TODO: read MBR file (if present) and use it's values
if (cylinders == 0) {
cylinders = 1024;
heads = 16;
sectors = 63;
}
n_first_sectors = sectors + 1;
sector_count = cylinders * heads * sectors;
hd_size = sector_count * 512;
size_in_mb = (Bit32u)(hd_size >> 20);
if (size_in_mb >= 2047) {
fat_type = 32;
sectors_per_cluster = 8;
BX_PANIC(("FAT32 required, but not supported yet"));
} else {
fat_type = 16;
if (size_in_mb >= 1023) {
sectors_per_cluster = 64;
} else if (size_in_mb >= 511) {
sectors_per_cluster = 32;
} else if (size_in_mb >= 255) {
sectors_per_cluster = 16;
} else {
sectors_per_cluster = 8;
}
}
current_cluster = 0xffff;
init_directories(dirname);
sector_count = faked_sectors + sectors_per_cluster * cluster_count;
if (n_first_sectors > 1)
init_mbr();
return 0;
}
void vvfat_image_t::close(void)
{
array_free(&fat);
array_free(&directory);
array_free(&mapping);
if (cluster_buffer != NULL)
delete [] cluster_buffer;
}
Bit64s vvfat_image_t::lseek(Bit64s offset, int whence)
{
if (whence == SEEK_SET) {
sector_num = (Bit32u)(offset / 512);
} else if (whence == SEEK_CUR) {
sector_num += (Bit32u)(offset / 512);
} else {
BX_ERROR(("lseek: mode not supported yet"));
return -1;
}
if (sector_num >= sector_count)
return -1;
return 0;
}
void vvfat_image_t::close_current_file(void)
{
if(current_mapping) {
current_mapping = NULL;
if (current_fd) {
::close(current_fd);
current_fd = 0;
}
}
current_cluster = 0xffff;
}
/* mappings between index1 and index2-1 are supposed to be ordered
* return value is the index of the last mapping for which end>cluster_num
*/
int vvfat_image_t::find_mapping_for_cluster_aux(int cluster_num, int index1, int index2)
{
while(1) {
int index3;
mapping_t* mapping;
index3 = (index1+index2) / 2;
mapping = (mapping_t*)array_get(&this->mapping, index3);
assert(mapping->begin < mapping->end);
if (mapping->begin >= (unsigned int)cluster_num) {
assert(index2 != index3 || index2 == 0);
if (index2 == index3)
return index1;
index2 = index3;
} else {
if (index1 == index3)
return (mapping->end <= (unsigned int)cluster_num) ? index2 : index1;
index1 = index3;
}
assert(index1 <= index2);
}
}
mapping_t* vvfat_image_t::find_mapping_for_cluster(int cluster_num)
{
int index = find_mapping_for_cluster_aux(cluster_num, 0, mapping.next);
mapping_t* mapping;
if (index >= (int)this->mapping.next)
return NULL;
mapping = (mapping_t*)array_get(&this->mapping, index);
if ((int)mapping->begin > cluster_num)
return NULL;
assert(((int)mapping->begin <= cluster_num) && ((int)mapping->end > cluster_num));
return mapping;
}
int vvfat_image_t::open_file(mapping_t* mapping)
{
if (!mapping)
return -1;
if (!current_mapping ||
strcmp(current_mapping->path, mapping->path)) {
/* open file */
int fd = ::open(mapping->path, O_RDONLY
#ifdef O_BINARY
| O_BINARY
#endif
#ifdef O_LARGEFILE
| O_LARGEFILE
#endif
);
if (fd < 0)
return -1;
close_current_file();
current_fd = fd;
current_mapping = mapping;
}
return 0;
}
int vvfat_image_t::read_cluster(int cluster_num)
{
mapping_t* mapping;
if (current_cluster != cluster_num) {
int result=0;
off_t offset;
assert(!current_mapping || current_fd || (current_mapping->mode & MODE_DIRECTORY));
if (!current_mapping
|| ((int)current_mapping->begin > cluster_num)
|| ((int)current_mapping->end <= cluster_num)) {
// binary search of mappings for file
mapping = find_mapping_for_cluster(cluster_num);
assert(!mapping || ((cluster_num >= (int)mapping->begin) && (cluster_num < (int)mapping->end)));
if (mapping && mapping->mode & MODE_DIRECTORY) {
close_current_file();
current_mapping = mapping;
read_cluster_directory:
offset = cluster_size * (cluster_num - current_mapping->begin);
cluster = (unsigned char*)directory.pointer+offset
+ 0x20 * current_mapping->info.dir.first_dir_index;
assert(((cluster -(unsigned char*)directory.pointer) % cluster_size) == 0);
assert((char*)cluster + cluster_size <= directory.pointer + directory.next * directory.item_size);
current_cluster = cluster_num;
return 0;
}
if (open_file(mapping))
return -2;
} else if (current_mapping->mode & MODE_DIRECTORY)
goto read_cluster_directory;
assert(current_fd);
offset = cluster_size * (cluster_num - current_mapping->begin) + current_mapping->info.file.offset;
if (::lseek(current_fd, offset, SEEK_SET) != offset)
return -3;
cluster = cluster_buffer;
result = ::read(current_fd, cluster, cluster_size);
if (result < 0) {
current_cluster = 0xffff;
return -1;
}
current_cluster = cluster_num;
}
return 0;
}
ssize_t vvfat_image_t::read(void* buf, size_t count)
{
char *cbuf = (char*)buf;
Bit32u scount = (Bit32u)(count / 512);
while (scount-- > 0) {
if (sector_num < faked_sectors) {
if (sector_num < n_first_sectors)
memcpy(buf, &first_sectors[sector_num * 0x200], 0x200);
else if (sector_num - n_first_sectors < sectors_per_fat)
memcpy(buf, &fat.pointer[(sector_num - n_first_sectors) * 0x200], 0x200);
else if ((sector_num - n_first_sectors - sectors_per_fat) < sectors_per_fat)
memcpy(buf, &fat.pointer[(sector_num - n_first_sectors - sectors_per_fat) * 0x200], 0x200);
} else {
Bit32u sector = sector_num - faked_sectors,
sector_offset_in_cluster = (sector % sectors_per_cluster),
cluster_num = sector / sectors_per_cluster;
if (read_cluster(cluster_num) != 0) {
memset(buf, 0, 0x200);
} else {
memcpy(cbuf, cluster + sector_offset_in_cluster * 0x200, 0x200);
}
}
sector_num++;
cbuf += 0x200;
}
return count;
}
ssize_t vvfat_image_t::write(const void* buf, size_t count)
{
Bit32u scount = (Bit32u)(count / 512);
if (sector_num < n_first_sectors)
return -1;
BX_ERROR(("VVFAT write not supported yet: sector=%d, count=%d", sector_num, scount));
return -1;
}
Bit32u vvfat_image_t::get_capabilities(void)
{
return HDIMAGE_READONLY | HDIMAGE_HAS_GEOMETRY;
}
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