Dumping Hardware information

Extracting the dumped information is a common requirement about HDT. This feature is available starting HDT 0.5.0 release.

To achieve this, HDT have to be able to write somewhere. The only way to do it today is by using TFTP.

Using TFTP

To use a TFTP server, Syslinux needs an IP address with some UDP ability. To achieve that, Syslinux is relying on the PXE service.<br> This implies that Dump mode only works with PXELinux. HDT will disable this feature when PXE isn't detected at boot time.

Regular PXE booting is using a TFTP server to download both pxebootstrap (pxelinux.0), its configuration file (i.e pxelinux.cfg/default) and all the booting code (a kernel, a floppy image, ...).

Choosing TFTP server

By default, HDT will use the TFTP server used during the PXE booting. This can be override with the tftp_ip option. Please consult the Dumping parameters page for more details.

Choosing TFTP Path

On this tftp server, by default, HDT will dump information in a hdt/ directory. This can be override with the dump_path option. Please consult the Dumping parameters page for more details.

Export File

By default, HDT will export content into a Gzipped cpio file. The default name is composed of <MAC_ADDRESS>+<DMI_VENDOR_NAME>+<DMI_PRODUCT_NAME>.

On VirtualBox?, we have the following filename : 08-00-27-99-b8-a5+VirtualBox?+innotek_GmbH

Note that ":" of a traditional address is translate into a "-" to avoid some errors on 'older' filesystems.

This filename isn't overridable today.

Extracting data

To extract data, you just have to run the following command :

zcat <filename> | cpio -id

It will produce a set of files which uses the name of the dumped component. I.e pci file will represent the dumped structures of the PCI devices.

This files are formatted in JSON and so can be parsed by any tool that supports JSON. A traditional grep could also works on some items.


Dumping can be started from the Dump to tftp menu. Under the cli, this can be achieved by using the dump command.