dolphin/Source/Core/Common/SDCardUtil.cpp

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2015-05-24 04:32:32 +00:00
// Copyright 2009 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.
/* mksdcard.c
**
** Copyright 2007, The Android Open Source Project
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are met:
** * Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** * Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in the
** documentation and/or other materials provided with the distribution.
** * Neither the name of Google Inc. nor the names of its contributors may
** be used to endorse or promote products derived from this software
** without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED BY Google Inc. ``AS IS'' AND ANY EXPRESS OR
** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
** MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
** EVENT SHALL Google Inc. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
** PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
** OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
** WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
** OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
** ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
// A simple and portable piece of code used to generate a blank FAT32 image file.
// Modified for Dolphin.
#include <cinttypes>
#include <cstddef>
#include <cstdio>
#include <cstring>
#include <ctime>
#include <string>
#include "Common/CommonFuncs.h"
#include "Common/CommonTypes.h"
#include "Common/FileUtil.h"
#include "Common/Logging/Log.h"
#include "Common/SDCardUtil.h"
#ifndef _WIN32
#include <unistd.h> // for unlink()
#endif
#ifdef _MSC_VER
#pragma warning(push)
#pragma warning(disable : 4310)
#endif
/* Believe me, you *don't* want to change these constants !! */
#define BYTES_PER_SECTOR 512
#define RESERVED_SECTORS 32
#define BACKUP_BOOT_SECTOR 6
#define NUM_FATS 2
#define BYTE_(p, i) (((u8*)(p))[(i)])
#define POKEB(p, v) BYTE_(p, 0) = (u8)(v)
#define POKES(p, v) (BYTE_(p, 0) = (u8)(v), BYTE_(p, 1) = (u8)((v) >> 8))
#define POKEW(p, v) \
(BYTE_(p, 0) = (u8)(v), BYTE_(p, 1) = (u8)((v) >> 8), BYTE_(p, 2) = (u8)((v) >> 16), \
BYTE_(p, 3) = (u8)((v) >> 24))
static u8 s_boot_sector[BYTES_PER_SECTOR]; /* Boot sector */
static u8 s_fsinfo_sector[BYTES_PER_SECTOR]; /* FS Info sector */
static u8 s_fat_head[BYTES_PER_SECTOR]; /* First FAT sector */
/* This is the date and time when creating the disk */
static unsigned int get_serial_id()
{
u16 lo, hi;
time_t now = time(nullptr);
struct tm tm = gmtime(&now)[0];
lo = (u16)(tm.tm_mday + ((tm.tm_mon + 1) << 8) + (tm.tm_sec << 8));
hi = (u16)(tm.tm_min + (tm.tm_hour << 8) + (tm.tm_year + 1900));
return lo + (hi << 16);
}
static unsigned int get_sectors_per_cluster(u64 disk_size)
{
u64 disk_MB = disk_size / (1024 * 1024);
if (disk_MB < 260)
return 1;
if (disk_MB < 8192)
return 4;
if (disk_MB < 16384)
return 8;
if (disk_MB < 32768)
return 16;
return 32;
}
static unsigned int get_sectors_per_fat(u64 disk_size, u32 sectors_per_cluster)
{
u64 divider;
/* Weird computation from MS - see fatgen103.doc for details */
disk_size -= RESERVED_SECTORS * BYTES_PER_SECTOR; /* Don't count 32 reserved sectors */
disk_size /= BYTES_PER_SECTOR; /* Disk size in sectors */
divider = ((256 * sectors_per_cluster) + NUM_FATS) / 2;
return (u32)((disk_size + (divider - 1)) / divider);
}
static void boot_sector_init(u8* boot, u8* info, u64 disk_size, const char* label)
{
u32 sectors_per_cluster = get_sectors_per_cluster(disk_size);
u32 sectors_per_fat = get_sectors_per_fat(disk_size, sectors_per_cluster);
u32 sectors_per_disk = (u32)(disk_size / BYTES_PER_SECTOR);
u32 serial_id = get_serial_id();
u32 free_count;
if (label == nullptr)
label = "DOLPHINSD";
POKEB(boot, 0xeb);
POKEB(boot + 1, 0x5a);
POKEB(boot + 2, 0x90);
strcpy((char*)boot + 3, "MSWIN4.1");
POKES(boot + 0x0b, BYTES_PER_SECTOR); /* Sector size */
POKEB(boot + 0xd, sectors_per_cluster); /* Sectors per cluster */
POKES(boot + 0xe, RESERVED_SECTORS); /* Reserved sectors before first FAT */
POKEB(boot + 0x10, NUM_FATS); /* Number of FATs */
POKES(boot + 0x11, 0); /* Max root directory entries for FAT12/FAT16, 0 for FAT32 */
POKES(boot + 0x13, 0); /* Total sectors, 0 to use 32-bit value at offset 0x20 */
POKEB(boot + 0x15, 0xF8); /* Media descriptor, 0xF8 == hard disk */
POKES(boot + 0x16, 0); /* Sectors per FAT for FAT12/16, 0 for FAT32 */
POKES(boot + 0x18, 9); /* Sectors per track (whatever) */
POKES(boot + 0x1a, 2); /* Number of heads (whatever) */
POKEW(boot + 0x1c, 0); /* Hidden sectors */
POKEW(boot + 0x20, sectors_per_disk); /* Total sectors */
/* Extension */
POKEW(boot + 0x24, sectors_per_fat); /* Sectors per FAT */
POKES(boot + 0x28, 0); /* FAT flags */
POKES(boot + 0x2a, 0); /* Version */
POKEW(boot + 0x2c, 2); /* Cluster number of root directory start */
POKES(boot + 0x30, 1); /* Sector number of FS information sector */
POKES(boot + 0x32, BACKUP_BOOT_SECTOR); /* Sector number of a copy of this boot sector */
POKEB(boot + 0x40, 0x80); /* Physical drive number */
POKEB(boot + 0x42, 0x29); /* Extended boot signature ?? */
POKEW(boot + 0x43, serial_id); /* Serial ID */
strncpy((char*)boot + 0x47, label, 11); /* Volume Label */
memcpy(boot + 0x52, "FAT32 ", 8); /* FAT system type, padded with 0x20 */
POKEB(boot + BYTES_PER_SECTOR - 2, 0x55); /* Boot sector signature */
POKEB(boot + BYTES_PER_SECTOR - 1, 0xAA);
/* FSInfo sector */
free_count = sectors_per_disk - 32 - 2 * sectors_per_fat;
POKEW(info + 0, 0x41615252);
POKEW(info + 484, 0x61417272);
POKEW(info + 488, free_count); /* Number of free clusters */
POKEW(info + 492, 3); /* Next free clusters, 0-1 reserved, 2 is used for the root dir */
POKEW(info + 508, 0xAA550000);
}
static void fat_init(u8* fat)
{
POKEW(fat, 0x0ffffff8); /* Reserve cluster 1, media id in low byte */
POKEW(fat + 4, 0x0fffffff); /* Reserve cluster 2 */
POKEW(fat + 8, 0x0fffffff); /* End of cluster chain for root dir */
}
static unsigned int write_sector(FILE* file, u8* sector)
{
return fwrite(sector, 1, 512, file) != 512;
}
static unsigned int write_empty(FILE* file, u64 count)
{
static u8 empty[64 * 1024];
count *= 512;
while (count > 0)
{
u64 len = sizeof(empty);
if (len > count)
len = count;
if (fwrite(empty, 1, (size_t)len, file) != (size_t)len)
return 1;
count -= len;
}
return 0;
}
bool SDCardCreate(u64 disk_size /*in MB*/, const std::string& filename)
{
u32 sectors_per_fat;
u32 sectors_per_disk;
// Convert MB to bytes
disk_size *= 1024 * 1024;
if (disk_size < 0x800000 || disk_size > 0x800000000ULL)
{
ERROR_LOG(COMMON,
"Trying to create SD Card image of size %" PRIu64 "MB is out of range (8MB-32GB)",
disk_size / (1024 * 1024));
return false;
}
// Pretty unlikely to overflow.
sectors_per_disk = (u32)(disk_size / 512);
sectors_per_fat = get_sectors_per_fat(disk_size, get_sectors_per_cluster(disk_size));
boot_sector_init(s_boot_sector, s_fsinfo_sector, disk_size, nullptr);
fat_init(s_fat_head);
File::IOFile file(filename, "wb");
FILE* const f = file.GetHandle();
if (!f)
{
ERROR_LOG(COMMON, "Could not create file '%s', aborting...", filename.c_str());
return false;
}
/* Here's the layout:
*
* boot_sector
* fsinfo_sector
* empty
* backup boot sector
* backup fsinfo sector
* RESERVED_SECTORS - 4 empty sectors (if backup sectors), or RESERVED_SECTORS - 2 (if no backup)
* first fat
* second fat
* zero sectors
*/
if (write_sector(f, s_boot_sector))
goto FailWrite;
if (write_sector(f, s_fsinfo_sector))
goto FailWrite;
if (BACKUP_BOOT_SECTOR > 0)
{
if (write_empty(f, BACKUP_BOOT_SECTOR - 2))
goto FailWrite;
if (write_sector(f, s_boot_sector))
goto FailWrite;
if (write_sector(f, s_fsinfo_sector))
goto FailWrite;
if (write_empty(f, RESERVED_SECTORS - 2 - BACKUP_BOOT_SECTOR))
goto FailWrite;
}
else
{
if (write_empty(f, RESERVED_SECTORS - 2))
goto FailWrite;
}
if (write_sector(f, s_fat_head))
goto FailWrite;
if (write_empty(f, sectors_per_fat - 1))
goto FailWrite;
if (write_sector(f, s_fat_head))
goto FailWrite;
if (write_empty(f, sectors_per_fat - 1))
goto FailWrite;
if (write_empty(f, sectors_per_disk - RESERVED_SECTORS - 2 * sectors_per_fat))
goto FailWrite;
return true;
FailWrite:
ERROR_LOG(COMMON, "Could not write to '%s', aborting...", filename.c_str());
if (unlink(filename.c_str()) < 0)
ERROR_LOG(COMMON, "unlink(%s) failed: %s", filename.c_str(), GetLastErrorMsg().c_str());
return false;
}
#ifdef _MSC_VER
#pragma warning(pop)
#endif