bool InitDriveThread::partitionDrive()
{
/* Partition layout:
*
* First 1MB (2048 blocks) kept empty for alignment
* Followed by FAT partition of RESCUE_PARTITION_SIZE (default 1 GB)
* Followed by extended partition spanning remainder of space
*/
QByteArray partitionTable;
int rescueBlocks = RESCUE_PARTITION_SIZE*1024*2;
mbr_table extended_mbr;
int startOfExtended = 2048+rescueBlocks + 5000 * 2048; // reserve space for WinIoT
int sizeOfDisk = sizeofSDCardInBlocks();
int sizeOfExtended = sizeOfDisk - startOfExtended;
partitionTable = "2048,"+QByteArray::number(rescueBlocks)+",0E\n"; /* FAT partition */
partitionTable += "0,0\n";
partitionTable += "0,0\n";
partitionTable += QByteArray::number(startOfExtended)+","+QByteArray::number(sizeOfExtended)+",X\n"; /* Extended partition with all remaining space */
/* Write out empty extended partition table with signature */
memset(&extended_mbr, 0, sizeof extended_mbr);
extended_mbr.signature[0] = 0x55;
extended_mbr.signature[1] = 0xAA;
QFile f("/dev/mmcblk0");
f.open(f.ReadWrite);
f.seek(((qint64)startOfExtended)*512L);
f.write((char *) &extended_mbr, sizeof(extended_mbr));
f.close();
/* Write main partition table */
QString cmd = QString("/sbin/sfdisk -uS /dev/mmcblk0");
QProcess proc;
proc.setProcessChannelMode(proc.MergedChannels);
proc.start(cmd);
proc.write(partitionTable);
proc.closeWriteChannel();
proc.waitForFinished(-1);
QThread::msleep(500);
return proc.exitCode() == 0;
}
bool InitDriveThread::zeroMbr()
{
/* First 512 bytes should be enough to zero out the MBR, but we zero out 8 kb to make sure we also erase any
* GPT primary header and get rid of any partitionless FAT headers.
* also zero out the last 4 kb of the card to get rid of any secondary GPT header
*
* Using conv=fsync to make sure we get notified of write errors
*/
return QProcess::execute("/bin/dd conv=fsync count=1 bs=8192 if=/dev/zero of="+_drive) == 0
&& QProcess::execute("/bin/dd conv=fsync count=8 bs=512 if=/dev/zero seek="+QString::number(sizeofSDCardInBlocks()-8)+" of="+_drive) == 0;
}
bool InitDriveThread::method_resizePartitions()
{
int newStartOfRescuePartition = getFileContents("/sys/class/block/mmcblk0p1/start").trimmed().toInt();
int newSizeOfRescuePartition = sizeofBootFilesInKB()/1000 + 100;
if (!umountSystemPartition())
{
emit error(tr("Error unmounting system partition."));
return false;
}
if (!QFile::exists("/dev/mmcblk0p1"))
{
// SD card does not have a MBR.
// Warn user that their SD card does not have an MBR and ask
// if they would like us to create one for them
QMessageBox::StandardButton answer;
emit query(tr("Would you like NOOBS to create one for you?\nWARNING: This will erase all data on your SD card"),
tr("Error: No MBR present on SD Card"),
&answer);
if(answer == QMessageBox::Yes)
{
emit statusUpdate(tr("Zeroing partition table"));
if (!zeroMbr())
{
emit error(tr("Error zero'ing MBR/GPT. SD card may be broken or advertising wrong capacity."));
return false;
}
// Create MBR containing single FAT partition
emit statusUpdate(tr("Writing new MBR"));
QProcess proc;
proc.setProcessChannelMode(proc.MergedChannels);
proc.start("/usr/sbin/parted /dev/mmcblk0 --script -- mktable msdos mkpartfs primary fat32 8192s -1");
proc.waitForFinished(-1);
if (proc.exitCode() != 0)
{
// Warn user if we failed to create an MBR on their card
emit error(tr("Error creating MBR")+"\n"+proc.readAll());
return false;
}
qDebug() << "Created missing MBR on SD card. parted output:" << proc.readAll();
// Advise user that their SD card has now been formatted
// suitably for installing NOOBS and that they will have to
// re-copy the files before rebooting
emit error(tr("SD card has now been formatted ready for NOOBS installation. Please re-copy the NOOBS files onto the card and reboot"));
return false;
}
else
{
emit error(tr("SD card has not been formatted correctly. Please reformat using the SD Association Formatting Tool and try again."));
return false;
}
}
emit statusUpdate(tr("Removing partitions 2,3,4"));
QFile f("/dev/mmcblk0");
f.open(f.ReadWrite);
// Seek to partition entry 2
f.seek(462);
// Zero out partition 2,3,4 to prevent parted complaining about invalid constraints
f.write(QByteArray(16*3, '\0'));
f.flush();
// Tell Linux to re-read the partition table
ioctl(f.handle(), BLKRRPART);
f.close();
QThread::msleep(500);
emit statusUpdate(tr("Resizing FAT partition"));
/* Relocating the start of the FAT partition is a write intensive operation
* only move it when it is not aligned on a MiB boundary already */
if (newStartOfRescuePartition < 2048 || newStartOfRescuePartition % 2048 != 0)
{
newStartOfRescuePartition = 8192; /* 4 MiB */
}
QString cmd = "/usr/sbin/parted --script /dev/mmcblk0 resize 1 "+QString::number(newStartOfRescuePartition)+"s "+QString::number(newSizeOfRescuePartition)+"M";
qDebug() << "Executing" << cmd;
QProcess p;
p.setProcessChannelMode(p.MergedChannels);
p.start(cmd);
p.closeWriteChannel();
p.waitForFinished(-1);
if (p.exitCode() != 0)
{
emit error(tr("Error resizing existing FAT partition")+"\n"+p.readAll());
return false;
}
qDebug() << "parted done, output:" << p.readAll();
QThread::msleep(500);
emit statusUpdate(tr("Creating extended partition"));
mbr_table extended_mbr;
QByteArray partitionTable;
int startOfOurPartition = getFileContents("/sys/class/block/mmcblk0p1/start").trimmed().toInt();
int sizeOfOurPartition = getFileContents("/sys/class/block/mmcblk0p1/size").trimmed().toInt();
int startOfExtended = startOfOurPartition + sizeOfOurPartition;
// Align on 4 MiB boundary
startOfExtended += 8192-(startOfExtended % 8192);
// BUGBUG - reserve space for WinIOT
startOfExtended += 5000 * 2048;
//
int sizeOfDisk = sizeofSDCardInBlocks();
int sizeOfExtended = sizeOfDisk - startOfExtended;
partitionTable = QByteArray::number(startOfOurPartition)+","+QByteArray::number(sizeOfOurPartition)+",0E\n"; /* FAT partition */
partitionTable += "0,0\n";
partitionTable += "0,0\n";
partitionTable += QByteArray::number(startOfExtended)+","+QByteArray::number(sizeOfExtended)+",X\n"; /* Extended partition with all remaining space */
qDebug() << "Writing partition table" << partitionTable;
/* Write out extended partition table with settings logical partition */
memset(&extended_mbr, 0, sizeof extended_mbr);
extended_mbr.part[0].starting_sector = EBR_PARTITION_OFFSET;
extended_mbr.part[0].nr_of_sectors = SETTINGS_PARTITION_SIZE;
extended_mbr.part[0].id = 0x83;
extended_mbr.signature[0] = 0x55;
extended_mbr.signature[1] = 0xAA;
f.open(f.ReadWrite);
f.seek(((qint64)startOfExtended)*512L);
f.write((char *) &extended_mbr, sizeof(extended_mbr));
f.flush();
f.close();
/* Let sfdisk write a proper partition table */
cmd = QString("/sbin/sfdisk -uS /dev/mmcblk0");
QProcess proc;
proc.setProcessChannelMode(proc.MergedChannels);
proc.start(cmd);
proc.write(partitionTable);
proc.closeWriteChannel();
proc.waitForFinished(-1);
if (proc.exitCode() != 0)
{
emit error(tr("Error creating extended partition")+"\n"+proc.readAll());
return false;
}
qDebug() << "sfdisk done, output:" << proc.readAll();
QThread::msleep(500);
/* For reasons unknown Linux sometimes
* only finds /dev/mmcblk0p2 and /dev/mmcblk0p1 goes missing */
if (!QFile::exists("/dev/mmcblk0p1"))
{
/* Probe again */
QProcess::execute("/usr/sbin/partprobe");
QThread::msleep(1500);
}
QProcess::execute("/sbin/mlabel p:RECOVERY");
emit statusUpdate(tr("Mounting FAT partition"));
if (!mountSystemPartition())
{
emit error(tr("Error mounting system partition."));
return false;
}
return true;
}
