VirtualBox LAN boot ROM
You can use gPXE as the LAN boot ROM in VirtualBox. The boot ROM can be set per-VM or globally for all VMs. Using gPXE instead of the default LAN boot ROM, VMs can be booted over HTTP, iSCSI, AoE, and gPXE's other advanced features are available.
Build the ROM image
Check which network adapter is configured for the VM.
Here are the adapters supported by VirtualBox v3.1.2 [from a VirtualBox (non-GPL ed.) on Fedora 12 (i686) installation]:
| VirtualBox Adapter 'type' | PCI Vendor ID | PCI Device ID | Mfr Name | Device Name | Notes |
|---|---|---|---|---|---|
| Am79C970A | 1022h | 2000h | AMD | PCnet-PCI II (AM79C970A) | |
| Am79C973 | 1022h | 2000h | AMD | PCnet-PCI III (AM79C973) | Default for Most Guest VM OS Choices |
| 82540EM | 8086h | 100Eh | Intel | Intel PRO/1000 MT Desktop (82540EM) | Default for Windows Vista/Windows 7 VMs |
| 82543GC | 8086h | 1004h | Intel | Intel PRO/1000 T Server (82543GC) | |
| 82545EM | 8086h | 100Fh | Intel | Intel PRO/1000 MT Server (82545EM) | |
| virtio | 1AF4h | 1000h | Qumranet? | Paravirtualized Network (virtio-net) |
Build the appropriate ROM image:
cd gpxe/src make bin/10222000.rom # for pcnet32 1022:2000
Fix up the ROM image
VirtualBox has the following requirements on ROM image size:
- Size must be 4K aligned (i.e. a multiple of 4096)
- Size must not be greater than 64K
Check that your image is not larger than 65536 bytes:
$ ls -l bin/10222000.rom | awk '{print $5}'
55296
Pad the image file to a 4K boundary:
$ python
>>> (55296 + 4095) & ~4095 # Round up to 4K aligned size
57344
>>> 57344 - 55296 # Calculate padding size
2048
>>> f = open('bin/10222000.rom', 'a')
>>> f.write('\0' * 2048) # Pad with zeroes
Configure the VM to use the LAN boot ROM
Use vboxmanage to set the LanBootRom path:
vboxmanage setextradata $VM_NAME VBoxInternal/Devices/pcbios/0/Config/LanBootRom /path/to/10222000.rom
Replace $VM_NAME with your VM's name. If you use “global” as $VM_NAME then all VMs will use the gPXE LAN boot ROM.
Now start the VM and press F12 to choose network booting:
virtualbox -startvm $VM_NAME
To automatically boot gPXE, change the VM boot priorities to try booting from the network first.
Unconfiguring the VM
If you wish to stop using gPXE:
vboxmanage setextradata $VM_NAME VBoxInternal/Devices/pcbios/0/Config/LanBootRom
