parted: disk_set

 
 2.4.2 disk_set
 --------------
 
  -- Command: disk_set FLAG STATE
 
      Changes a flag on the disk.  A flag can be either "on" or "off".
      Some or all of these flags will be available, depending on what
      disk label you are using:
 
      'pmbr_boot'
           (GPT) - this flag enables the boot flag on the GPT's
           protective MBR partition.
 
      The disk's flags are displayed by the print command on the "Disk
      Flags:" line.  They are also output as the last field of the disk
      information in machine mode.
 
           (parted) disk_set pmbr_boot on
 
      Set the PMBR's boot flag.