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rufus/file.c
Pete Batard cbc54d764d [boot] added FAT16 bootable MS-DOS support
* also fixed broken FAT32 bootable MS-DOS
* also added extended error report in file.c
2011-12-02 00:11:53 +00:00

144 lines
4.5 KiB
C

/******************************************************************
Copyright (C) 2009 Henrik Carlqvist
Modified for Rufus/Windows (C) 2011 Pete Batard
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
******************************************************************/
#include <stdio.h>
#include <string.h>
#include "rufus.h"
#include "file.h"
int write_sectors(HANDLE hDrive, size_t SectorSize,
size_t StartSector, size_t nSectors,
const void *pBuf, size_t BufSize)
{
LARGE_INTEGER ptr;
DWORD Size;
if(SectorSize * nSectors > BufSize)
{
uprintf("write_sectors: Buffer is too small\n");
return 0;
}
ptr.QuadPart = StartSector*SectorSize;
if(!SetFilePointerEx(hDrive, ptr, NULL, FILE_BEGIN))
{
uprintf("write_sectors: Could not access sector %d - %s\n", StartSector, WindowsErrorString());
return 0;
}
if((!WriteFile(hDrive, pBuf, (DWORD)BufSize, &Size, NULL)) || (Size != BufSize))
{
uprintf("write_sectors: Write error - %s\n", WindowsErrorString());
uprintf(" StartSector:%0X, nSectors:%0X, SectorSize:%0X\n", StartSector, nSectors, SectorSize);
return 0;
}
return 1;
}
int read_sectors(HANDLE hDrive, size_t SectorSize,
size_t StartSector, size_t nSectors,
void *pBuf, size_t BufSize)
{
LARGE_INTEGER ptr;
DWORD Size;
if(SectorSize * nSectors > BufSize)
{
uprintf("read_sectors: Buffer is too small\n");
return 0;
}
ptr.QuadPart = StartSector*SectorSize;
if(!SetFilePointerEx(hDrive, ptr, NULL, FILE_BEGIN))
{
uprintf("read_sectors: Could not access sector %d - %s\n", StartSector, WindowsErrorString());
return 0;
}
if((!ReadFile(hDrive, pBuf, (DWORD)BufSize, &Size, NULL)) || (Size != BufSize))
{
uprintf("read_sectors: Read error - %s\n", WindowsErrorString());
uprintf(" StartSector:%0X, nSectors:%0X, SectorSize:%0X\n", StartSector, nSectors, SectorSize);
return 0;
}
return 1;
}
/* Use a bastardized fp that contains a Windows handle and the sector size */
int contains_data(FILE *fp, size_t Position,
const void *pData, size_t Len)
{
unsigned char aucBuf[MAX_DATA_LEN];
HANDLE hDrive = (HANDLE)fp->_ptr;
size_t SectorSize = (size_t)fp->_bufsiz;
size_t StartSector, EndSector, NumSectors;
StartSector = Position/SectorSize;
EndSector = (Position+Len+SectorSize-1)/SectorSize;
NumSectors = EndSector - StartSector;
if((NumSectors*SectorSize) > MAX_DATA_LEN)
{
uprintf("Please increase MAX_DATA_LEN in file.h\n");
return 0;
}
if(!read_sectors(hDrive, SectorSize, StartSector,
NumSectors, aucBuf, sizeof(aucBuf)))
return 0;
if(memcmp(pData, &aucBuf[Position - StartSector*SectorSize], Len))
return 0;
return 1;
} /* contains_data */
/* May read/write the same sector many times, but compatible with existing ms-sys */
int write_data(FILE *fp, size_t Position,
const void *pData, size_t Len)
{
unsigned char aucBuf[MAX_DATA_LEN];
HANDLE hDrive = (HANDLE)fp->_ptr;
size_t SectorSize = (size_t)fp->_bufsiz;
size_t StartSector, EndSector, NumSectors;
StartSector = Position/SectorSize;
EndSector = (Position+Len+SectorSize-1)/SectorSize;
NumSectors = EndSector - StartSector;
if((NumSectors*SectorSize) > MAX_DATA_LEN)
{
uprintf("Please increase MAX_DATA_LEN in file.h\n");
return 0;
}
/* Data to write may not be aligned on a sector boundary => read into a sector buffer first */
if(!read_sectors(hDrive, SectorSize, StartSector,
NumSectors, aucBuf, sizeof(aucBuf)))
return 0;
if(!memcpy(&aucBuf[Position - StartSector*SectorSize], pData, Len))
return 0;
if(!write_sectors(hDrive, SectorSize, StartSector,
NumSectors, aucBuf, sizeof(aucBuf)))
return 0;
return 1;
} /* write_data */