vbetool

vbetool command [options]

dpms [on|off|standby|suspend|resume]
    Sets or queries the DPMS (Display Power Management Signaling) state.
on enables the display.
off powers off the display.
standby, suspend, and resume set corresponding power saving modes.

vgastate save filename
    Saves the VGA state to the specified filename.

vgastate restore filename
    Restores the VGA state from the specified filename.

pcirom filename
    Executes the PCI ROM loaded from filename. This is often used for initializing the graphics card.

dumpvbt filename
    Dumps VBT (Video Bios Table) into file. If file exist than will be overwriten.

bios
    Runs the BIOS startup code

post
    Runs the POST (Power-On Self-Test) code within the video BIOS. It perform init and setup device.

pm
    Runs the power management function of the VBIOS.

-v
    Verbose mode, provides more detailed output.

The vbetool command allows you to execute x86 real-mode code, primarily for interacting with the Video BIOS (VBIOS) of your graphics card. This is especially useful in headless systems (servers without monitors) where you might need to initialize the graphics card for proper operation, such as enabling power management features or configuring framebuffers even without a connected display. vbetool can also be used to save and restore the video card's state. It can be a powerful debugging tool when used with care. Improper use can lead to system instability.

vbetool directly manipulates hardware and can potentially cause system crashes or instability if used incorrectly. Use with caution. Requires root privileges to execute.

A common use case is to initialize the graphics card in a headless server. You can use the command 'vbetool post' to execute the Power-On Self-Test within the video BIOS. This can properly initialize the card even without a connected monitor.

Because vbetool gives direct access to hardware, it's vital to run it only when necessary and under controlled circumstances. Unrestricted access to vbetool could potentially be exploited to modify system settings or cause damage.

vbetool was developed to address the needs of headless servers and embedded systems where access to the video BIOS is required without a physical display. It evolved as a utility for initializing graphics cards and managing their power states in such environments. The tool become more popular as the number of embedded systems without displays grew. Usage spread into fixing boot issues or diagnosing faulty graphic cards.

setpci(8), lspci(8)