Bool ISOInit(CDrv *dv,I64 blk)
{
  CBlkDev *bd=dv->bd;
  I64 spc=bd->blk_size>>BLK_SIZE_BITS,i=blk/spc,drv_offset=0;
  CISOPriDesc *iso=MAlloc(bd->blk_size);
  CISODirEntry *de;
  Bool unlock,res=FALSE;
  U8 buf[8];
  try
  {
    unlock=DrvLock(dv);
    dv->fs_type=FSt_ISO9660;
    dv->spc=spc;
    dv->data_area=dv->root_clus=dv->drv_offset=bd->drv_offset=dv->size=0;
    while (TRUE)
    {
      dv->size=MaxI64(dv->size,(i+1)*spc);
      BlkRead(dv,iso,i*spc,spc);
      buf[0](U32)=iso->id[0](U32);
      buf[4](U16)=iso->id[4](U8);
      switch (LstMatch(buf,"CD001\0CDW02\0BEA01\0BOOT2\0NSR02\0NSR03\0TEA01\0",
                       LMF_EXACT))
      {
      case 0:
        switch (iso->type)
        {
        case ISOT_BOOT_RECORD:
          drv_offset+=(2*DVD_BLK_SIZE+DVD_BLK_SIZE)/BLK_SIZE;
          break;
        case ISOT_SUPPLEMENTARY_DESC:
          de=&iso->root_dir_record;
          dv->size=iso->vol_space_size.little*bd->blk_size>>BLK_SIZE_BITS;
          if (!StrCmp(iso->publisher_id,"TempleOS RedSea"))
          {
            dv->fs_type=FSt_REDSEA;
            bd->drv_offset=dv->drv_offset=19<<2+drv_offset;
            bd->max_blk=dv->size-1;
            dv->size-=bd->drv_offset;
            RedSeaInit(dv);
          }
          else
            dv->root_clus=de->loc.little;
          res=TRUE;
          goto di_done;
        case ISOT_TERMINATOR:
          throw('Drv');
        }
        break;
      default: //Its normal for ISO3346 to read NULL blk as terminator
        PrintErr("File System Not Supported\n");
        throw('Drv');
      }
      i++;
    }
di_done:
    Free(iso);
    if (unlock)
      DrvUnlock(dv);
  }
  catch
  {
    dv->fs_type=FSt_ISO9660;
    dv->spc=spc;
    dv->drv_offset=bd->drv_offset=dv->data_area=dv->root_clus=0;
    Free(iso);
    if (unlock)
      DrvUnlock(dv);
  }
  return res;
}

U0 DVDImageRead(U8 dvd_drv_let,U8 *out_name)
{//Read entire CD/DVD image into ISO file.
  CDrv *dv=Let2Drv(dvd_drv_let);
  CBlkDev *bd=dv->bd;
  U8 *buf=MAlloc(COPY_BUF_BLKS<<BLK_SIZE_BITS),
      *out_name2=ExtDft(out_name,"ISO");
  CFile *f=FOpen(out_name2,"w");
  I64 n,spc=bd->blk_size>>BLK_SIZE_BITS,blk=0,cnt,retry;
  BlkDevInit(bd);
  if (bd->type!=BDT_ATAPI)
    throw('BlkDev');
  if (!out_name)
    out_name=blkdev.dft_iso_filename;
  cnt=CeilU64(dv->size,spc);
  while (cnt>0)
  {
    if (cnt>COPY_BUF_BLKS)
      n=COPY_BUF_BLKS;
    else
      n=cnt;
    if (n>bd->max_reads)
      n=bd->max_reads;
    retry=4;
    while (--retry)
      if (ATAPIReadBlks2(bd,tS+7.0+0.004*n/spc,buf,blk/spc,n/spc,TRUE))
//n is 0x800 if max_reads.  Up to 8 additional seconds
        break;
    if (!retry)
      ATAPIReadBlks2(bd,0,buf,blk/spc,n/spc,TRUE);
    FBlkWrite(f,buf,blk,n);
    cnt-=n;
    blk+=n;
  }
  FClose(f);
  Free(buf);
  Free(out_name2);
}

class CDualBuf
{
  U8 *buf0,*buf1;
  I64 in_buf,out_buf,cnt;
  U8 *filename;
  CBlkDev *dvd_bd;
};

U0 DVDImageWriteTask(CDualBuf *d)
{
  U8 *buf;
  I64 n,blk=0,cnt=d->cnt;
  CFile *f;
  if (FileAttr(d->filename)&RS_ATTR_CONTIGUOUS)
    f=FOpen(d->filename,"rc");
  else
    f=FOpen(d->filename,"r");
  while (cnt>0)
  {
    if (cnt>COPY_BUF_BLKS)
      n=COPY_BUF_BLKS;
    else
      n=cnt;
    if (n>d->dvd_bd->max_writes)
      n=d->dvd_bd->max_writes;
    if (d->in_buf&1)
      buf=d->buf1;
    else
      buf=d->buf0;
    while (d->in_buf>d->out_buf+1)
      Yield;
    FBlkRead(f,buf,blk,n);
    d->in_buf++;
    cnt-=n;
    blk+=n;
  }
  FClose(f);
}

U0 DVDImageWrite(U8 dvd_drv_let,U8 *in_name=NULL,I64 media_type=MT_DVD)
{//Write CD/DVD ISO file to disk.
  CDualBuf *d=CAlloc(sizeof(CDualBuf));
  U8 *buf,*in_name2,*in_name3;
  I64 i,n,spc,blk=0,cnt;
  CDrv *dv=Let2Drv(dvd_drv_let);
  CBlkDev *bd=dv->bd,*bd2;
  CTask *task;
  CFile *f;
  if (!in_name)
    in_name=blkdev.dft_iso_filename;
  in_name3=ExtDft(in_name,"ISO");
  in_name2=FileNameAbs(in_name3);
  f=FOpen(in_name2,"r");
  if (!f)
  {
    Free(d);
    return;
  }
  cnt=(FSize(f)+BLK_SIZE-1)>>BLK_SIZE_BITS;
  FClose(f);
  if (bd->type!=BDT_ATAPI)
    throw('BlkDev');
  bd2=Let2BlkDev(*in_name2);
  while (bd2->lock_fwding)
    bd2=bd2->lock_fwding;  //If two blkdevs on same controller, use one lock
  if ((bd2->type==BDT_ATA || bd2->type==BDT_ATAPI) &&
      bd2->base0==bd->base0)
  {
    PrintErr("Can't burn CD/DVD on same ATA controller as file.\n\n");
    throw('BlkDev');
  }
  bd->flags|=BDF_READ_ONLY_OVERRIDE;
  BlkDevInit(bd);
  spc=bd->blk_size>>BLK_SIZE_BITS;
  if (dv->size<cnt)
    dv->size=cnt;
  d->filename=in_name2;
  d->dvd_bd=bd;
  d->buf0=MAlloc(COPY_BUF_BLKS<<BLK_SIZE_BITS);
  d->buf1=MAlloc(COPY_BUF_BLKS<<BLK_SIZE_BITS);
  d->cnt=cnt;
  task=Spawn(&DVDImageWriteTask,d,"Write CD/DVD");
  while (d->in_buf<=d->out_buf)
    Yield;
  BlkDevLock(bd);
  ATAPIWaitReady(bd,0);
  progress1=0;
  progress1_max=cnt;
  StrCpy(progress1_desc,"Writing");
  while (cnt>0)
  {
    if (cnt>COPY_BUF_BLKS)
      n=COPY_BUF_BLKS;
    else
      n=cnt;
    if (n>bd->max_writes)
      n=bd->max_writes;
    if (d->out_buf&1)
      buf=d->buf1;
    else
      buf=d->buf0;
    while (d->in_buf<=d->out_buf)
      Yield;
    ATAPIWriteBlks(bd,buf,blk/spc,(n+spc-1)/spc);
    d->out_buf++;
    cnt-=n;
    blk+=n;
    progress1+=n;
  }
  ATAPISync(bd);
  progress1=0;
  progress1_max=2;
  StrCpy(progress1_desc,"Closing");
  for (i=0; i<2; i++)
  {
    ATAPIClose(bd,0x100,i); //Close tracks
    progress1++;
  }
  ATAPISync(bd);
  ATAPIClose(bd,0x200); //close disk
  ATAPISync(bd);
  if (media_type==MT_DVD)
  {
    ATAPIClose(bd,0x300);
    ATAPISync(bd);
  }
  *progress1_desc=0;
  progress1=progress1_max=0;
  bd->flags&=~BDF_READ_ONLY_OVERRIDE;
  BlkDevUnlock(bd);
  Free(d->buf0);
  Free(d->buf1);
  Free(in_name2);
  Free(in_name3);
  Free(d);
}