<!-- Code generated from the comments of the Config struct in builder/virtualbox/iso/builder.go; DO NOT EDIT MANUALLY -->

- `chipset` (string) - The chipset to be used: PIIX3 or ICH9.
  When set to piix3, the firmare is PIIX3. This is the default.
  When set to ich9, the firmare is ICH9.

- `firmware` (string) - The firmware to be used: BIOS or EFI.
  When set to bios, the firmare is BIOS. This is the default.
  When set to efi, the firmare is EFI.

- `nested_virt` (bool) - Nested virtualization: false or true.
  When set to true, nested virtualisation (VT-x/AMD-V) is enabled.
  When set to false, nested virtualisation is disabled. This is the default.

- `rtc_time_base` (string) - RTC time base: UTC or local.
  When set to true, the RTC is set as UTC time.
  When set to false, the RTC is set as local time. This is the default.

- `disk_size` (uint) - The size, in megabytes, of the hard disk to create for the VM. By
  default, this is 40000 (about 40 GB).

- `nic_type` (string) - The NIC type to be used for the network interfaces.
  When set to 82540EM, the NICs are Intel PRO/1000 MT Desktop (82540EM). This is the default.
  When set to 82543GC, the NICs are Intel PRO/1000 T Server (82543GC).
  When set to 82545EM, the NICs are Intel PRO/1000 MT Server (82545EM).
  When set to Am79C970A, the NICs are AMD PCNet-PCI II network card (Am79C970A).
  When set to Am79C973, the NICs are AMD PCNet-FAST III network card (Am79C973).
  When set to Am79C960, the NICs are AMD PCnet-ISA/NE2100 (Am79C960).
  When set to virtio, the NICs are VirtIO.

- `audio_controller` (string) - The audio controller type to be used.
  When set to ac97, the audio controller is ICH AC97. This is the default.
  When set to hda, the audio controller is Intel HD Audio.
  When set to sb16, the audio controller is SoundBlaster 16.

- `gfx_controller` (string) - The graphics controller type to be used.
  When set to vboxvga, the graphics controller is VirtualBox VGA. This is the default.
  When set to vboxsvga, the graphics controller is VirtualBox SVGA.
  When set to vmsvga, the graphics controller is VMware SVGA.
  When set to none, the graphics controller is disabled.

- `gfx_vram_size` (uint) - The VRAM size to be used. By default, this is 4 MiB.

- `gfx_accelerate_3d` (bool) - 3D acceleration: true or false.
  When set to true, 3D acceleration is enabled.
  When set to false, 3D acceleration is disabled. This is the default.

- `gfx_efi_resolution` (string) - Screen resolution in EFI mode: WIDTHxHEIGHT.
  When set to WIDTHxHEIGHT, it provides the given width and height as screen resolution
  to EFI, for example 1920x1080 for Full-HD resolution. By default, no screen resolution
  is set. Note, that this option only affects EFI boot, not the (default) BIOS boot.

- `guest_os_type` (string) - The guest OS type being installed. By default this is other, but you can
  get dramatic performance improvements by setting this to the proper
  value. To view all available values for this run VBoxManage list
  ostypes. Setting the correct value hints to VirtualBox how to optimize
  the virtual hardware to work best with that operating system.

- `hard_drive_discard` (bool) - When this value is set to true, a VDI image will be shrunk in response
  to the trim command from the guest OS. The size of the cleared area must
  be at least 1MB. Also set hard_drive_nonrotational to true to enable
  TRIM support.

- `hard_drive_interface` (string) - The type of controller that the primary hard drive is attached to,
  defaults to ide. When set to sata, the drive is attached to an AHCI SATA
  controller. When set to scsi, the drive is attached to an LsiLogic SCSI
  controller. When set to pcie, the drive is attached to an NVMe
  controller. When set to virtio, the drive is attached to a VirtIO
  controller. Please note that when you use "pcie", you'll need to have
  Virtualbox 6, install an [extension
  pack](https://www.virtualbox.org/wiki/Downloads#VirtualBox6.0.14OracleVMVirtualBoxExtensionPack)
  and you will need to enable EFI mode for nvme to work, ex:
  
  In JSON:
  ```json
   "vboxmanage": [
        [ "modifyvm", "{{.Name}}", "--firmware", "EFI" ],
   ]
  ```
  
  In HCL2:
  ```hcl
   vboxmanage = [
        [ "modifyvm", "{{.Name}}", "--firmware", "EFI" ],
   ]
  ```

- `sata_port_count` (int) - The number of ports available on any SATA controller created, defaults
  to 1. VirtualBox supports up to 30 ports on a maximum of 1 SATA
  controller. Increasing this value can be useful if you want to attach
  additional drives.

- `nvme_port_count` (int) - The number of ports available on any NVMe controller created, defaults
  to 1. VirtualBox supports up to 255 ports on a maximum of 1 NVMe
  controller. Increasing this value can be useful if you want to attach
  additional drives.

- `hard_drive_nonrotational` (bool) - Forces some guests (i.e. Windows 7+) to treat disks as SSDs and stops
  them from performing disk fragmentation. Also set hard_drive_discard to
  true to enable TRIM support.

- `iso_interface` (string) - The type of controller that the ISO is attached to, defaults to ide.
  When set to sata, the drive is attached to an AHCI SATA controller.
  When set to virtio, the drive is attached to a VirtIO controller.

- `disk_additional_size` ([]uint) - Additional disks to create. Uses `vm_name` as the disk name template and
  appends `-#` where `#` is the position in the array. `#` starts at 1 since 0
  is the default disk. Each value represents the disk image size in MiB.
  Each additional disk uses the same disk parameters as the default disk.
  Unset by default.

- `keep_registered` (bool) - Set this to true if you would like to keep the VM registered with
  virtualbox. Defaults to false.

- `skip_export` (bool) - Defaults to false. When enabled, Packer will not export the VM. Useful
  if the build output is not the resultant image, but created inside the
  VM.

- `vm_name` (string) - This is the name of the OVF file for the new virtual machine, without
  the file extension. By default this is packer-BUILDNAME, where
  "BUILDNAME" is the name of the build.