install.c

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/*
 *  FreeLoader - install.c
 *
 *  Copyright (C) 2001  Brian Palmer  <brianp@sginet.com>
 *
 *  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.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
#include <windows.h>
#include <tchar.h>
#include <stdio.h>
#include "install.h"
#include "volume.h"
 
/*
 * These includes are required to define
 * the fat_data and fat32_data arrays.
 */
#include "fat.h"
#include "fat32.h"
 
BOOL    BackupBootSector(LPCTSTR lpszVolumeName);
BOOL    InstallBootSector(LPCTSTR lpszVolumeType);
 
int main(int argc, char *argv[])
{
    if (argc < 3)
    {
        _tprintf(_T("syntax: install x: [fs_type]\nwhere fs_type is fat or fat32\n"));
        return -1;
    }
 
    if (!OpenVolume(argv[1]))
    {
        return -1;
    }
 
    BackupBootSector(argv[1]);
 
    InstallBootSector(argv[2]);
 
    _tprintf(_T("You must now copy freeldr.sys & freeldr.ini to %s.\n"), argv[1]);
 
    CloseVolume();
 
    return 0;
}
 
BOOL BackupBootSector(LPCTSTR lpszVolumeName)
{
    HANDLE    hBackupFile;
    TCHAR    szFileName[MAX_PATH];
    ULONG    Count;
    BYTE    BootSectorBuffer[512];
    DWORD    dwNumberOfBytesWritten;
    BOOL    bRetVal;
 
    //
    // Find the next unused filename and open it
    //
    for (Count=0; ; Count++)
    {
        //
        // Generate the next filename
        //
        _stprintf(szFileName, _T("%s\\bootsect.%03ld"), lpszVolumeName, Count);
 
        //
        // Try to create a new file, fail if exists
        //
        hBackupFile = CreateFile(szFileName, GENERIC_WRITE, 0, NULL, CREATE_NEW, /*FILE_ATTRIBUTE_SYSTEM*/0, NULL);
 
        //
        // Check to see if it worked
        //
        if (hBackupFile != INVALID_HANDLE_VALUE)
        {
            break;
        }
 
        //
        // Nope, didn't work
        // Check to see if it already existed
        //
        if (!(GetLastError() != ERROR_ALREADY_EXISTS))
        {
            _tprintf(_T("%s:%d: "), __FILE__, __LINE__);
            _tprintf(_T("Boot sector backup failed. Error code %ld.\n"), GetLastError());
            return FALSE;
        }
    }
 
    //
    // Try to read the boot sector
    //
    if (!ReadVolumeSector(0, BootSectorBuffer))
    {
        CloseHandle(hBackupFile);
        return FALSE;
    }
 
    //
    // Try to write the boot sector data to the file
    //
    bRetVal = WriteFile(hBackupFile, BootSectorBuffer, 512, &dwNumberOfBytesWritten, NULL);
    if (!bRetVal || (dwNumberOfBytesWritten != 512))
    {
        CloseHandle(hBackupFile);
        _tprintf(_T("%s:%d: "), __FILE__, __LINE__);
        _tprintf(_T("WriteFile() failed. Error code %ld.\n"), GetLastError());
        return FALSE;
    }
 
    _tprintf(_T("Boot sector backed up to file: %s\n"), szFileName);
 
    CloseHandle(hBackupFile);
 
    return TRUE;
}
 
BOOL InstallBootSector(LPCTSTR lpszVolumeType)
{
    BYTE    BootSectorBuffer[512];
 
    //
    // Read in the old boot sector
    //
    if (!ReadVolumeSector(0, BootSectorBuffer))
    {
        return FALSE;
    }
 
    if (_tcsicmp(lpszVolumeType, _T("fat")) == 0)
    {
        //
        // Update the BPB in the new boot sector
        //
        memcpy((fat_data+3), (BootSectorBuffer+3), 59 /*fat BPB length*/);
 
        //
        // Write out new boot sector
        //
        if (!WriteVolumeSector(0, fat_data))
        {
            return FALSE;
        }
    }
    else if (_tcsicmp(lpszVolumeType, _T("fat32")) == 0)
    {
        //
        // Update the BPB in the new boot sector
        //
        memcpy((fat32_data+3), (BootSectorBuffer+3), 87 /*fat32 BPB length*/);
 
        //
        // Write out new boot sector
        //
        if (!WriteVolumeSector(0, fat32_data))
        {
            return FALSE;
        }
 
        //
        // Write out new extra sector
        //
        if (!WriteVolumeSector(14, (fat32_data+512)))
        {
            return FALSE;
        }
    }
    else
    {
        _tprintf(_T("%s:%d: "), __FILE__, __LINE__);
        _tprintf(_T("File system type %s unknown.\n"), lpszVolumeType);
        return FALSE;
    }
 
    _tprintf(_T("%s boot sector installed.\n"), lpszVolumeType);
 
    return TRUE;
}