As a first step, check the uberXMHF (pc-intel-x86_32) Hardware Requirements, and be sure to enable the corresponding BIOS options (enable TPM, enable VT-x, enable VT-d, and enable TXT–often many of these are disabled by default in the BIOS). Also make sure your BIOS is up to date; you could ruin your motherboard if your BIOS is buggy. Secondly, ensure that you are running one of the supported guest operating systems (see uberXMHF (pc-intel-x86_32) Supported Guest Operating Systems– 32-bit page tables, blacklisted kernel modules ). Thirdly, ensure you have copied the mico-hypervisor (xmhf-x86-vmx-x86pc.bin.gz) and the SINIT module (Intel TXT webpage) into your /boot/ directory. Lastly, configure your system to boot uberXMHF as described below.

Configure target system to boot uberXMHF

You will need to install Grub 1, if you haven’t already. On most modern Linux distributions, you will need to downgrade from Grub 2. On Windows machines without a Linux installation, you will need to install Grub. This can be done by installing a minimal Linux installation, which will typically take care of non-destructively repartitioning for you.

Downgrade from Grub 2 to Grub 1

Booting uberXMHF is currently only supported using Grub 1. If Grub 2 is already installed (as it typically is on recent Linux distributions), you will need to downgrade to Grub 1.

The following commands accomplish the above task on Ubuntu:

# remove all GRUB 2 files (answer yes to any questions)
sudo apt-get purge grub-pc grub-common os-prober
sudo apt-get purge grub-gfxpayload-lists
sudo apt-get install grub
# If asked about creating a /boot/grub/menu.lst answer yes
sudo update-grub
grub-install /dev/sda

You should have an automatically filled in /boot/grub/menu.lst with entries for any kernels installed on the machine. While unlikely, check this file for any lines attempting to load GRUB 2 (such as the snippet below):

title          Chainload into GRUB 2
root           b5912383-7f9e-4911-b51d-b14ce8cea70b
kernel         /boot/grub/core.img

For further details about downgradeing GRUB, please refer to the following posts on downgrading GRUB for Ubuntu and downgrading GRUB for Debian respectively.

Get the correct SINIT module

uberXMHF launches itself with a dynamic root of trust. On Intel platforms, this requires a signed SINIT module provided by Intel, that matches your platform CPU and chipset.

SINIT modules can be found here:

You can determine the appropriate SINIT module by determining your CPU’s Product Collection and Code Name. If unsure about these details. First, find your CPU’s model name (cat /proc/cpuinfo | grep 'model name'). Second, use the CPU model to search Intel’s product specifications. You should now have your CPU’s Product Collection and Code Name, which you can use to identify the appropriate SINIT module. Note, as of the time of writing, there was a second table at the bottom of the page with the attached SINIT modules (in case the links in the main table do not work).

Ensure that the .BIN from this module is copied into your /boot/ directory.

Building and Installing uberXMHF binaries

If you haven’t already built and installed uberXMHF, see Verifying and Building uberXMHF (pc-intel-x86_32)

Ensure that the xmhf-x86-vmx-x86pc.bin.gz is copied into your /boot/ directory.

Adding a Grub entry to boot Linux

You will need to add a Grub entry to /boot/grub/menu.lst. To ensure that it doesn’t get clobbered, put it outside the AUTOMAGIC KERNEL LIST (i.e., append it to the end of the file).

To boot a Linux guest, we create a grub entry that loads the micro-hypervisor, and then re-loads grub. When booting the machine, first choose the uberXMHF entry, and then choose a normal Linux entry.

A grub entry for uberXMHF should look something like this:

title uberXMHF
uuid   xxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx               # copy this from an AUTOMAGIC entry
kernel /boot/xmhf-x86-vmx-x86pc.bin.gz serial=115200,8n1,0x3f8 nmi_watchdog=0 # substitute in the correct serial address
modulenounzip (hd0)+1                                     # should point to where grub is installed
modulenounzip /boot/4th_gen_i5_i7_SINIT_75.BIN            # Intel TXT SINIT AC module

This will boot uberXMHF with debug output going to the specified serial port, and then reload grub. Note, check if the AUTOMAGIC KERNELS refernce /boot/vmlinuz-* or simply /vmlinuz-* and have your uberXMHF entry match (i.e., some do not require the /boot/ prefix in the above example).

Additionally, you must specify new command line option to disable the NMI watchdog kernel-module on your guest OS (linux). The added command line options must include nmi_watchdog=0

If your Default OS (the Linux kernel that will be booting after the micro-hypervisor) uses an LVM filesystem, you might need to alter its GRUB entry. Modify the kernel entry to specify the root as the LVM disk. For example, change:

kernel     /vmlinuz-4.4.236+ root=UUID=xxxxxxxx-xxxx-xxxx-xxxxxxxxxxxx ro quiet splash


kernel      /vmlinuz-4.4.236+ root=/dev/${Volume Group name}/root ro text nomodeset nmi_watchdog=0

Where you can find the appropriate ${Volume Group name} using sudo vgs --noheadings -o vg_name

savedefault for unattended boot

Booting linux involves loading the grub menu twice. The first time you must select the uberXMHF entry, and the second time you must select an OS entry. You can automate this by using savedefault.

Set grub to boot the saved default:

default         saved

Have your uberXMHF entry and what you want as your default OS entry save each-other as the new default:

title Default OS
savedefault 1         # where the number equates to the subsequent grub entry to load (i.e. 0 == the first in the list of options)

title uberXMHF
savedefault 0

The parameter to savedefault is the menu entry that you would like as the new default.

Example GRUB menu.lst

A minimal grub menu.lst example is shown below.

default saved

title          Default OS
uuid           c8abe43f-8658-42bb-b238-60b97320c50
kernel         /vmlinuz-4.4.236+ root=/dev/uberXMHF-vg/root ro text nomodeset memblock=debug nmi_watchdog=0
initrd         /initrd.img-4.4.236+
savedefault    1

title          uberXMHF
uuid           c8abe43f-8658-42bb-b238-60b97320c50
kernel         /xmhf-x86-vmx-x86pc.bin.gz serial=11520,8n1,0x3f8
modulenounzip  (hd0)+1
modulenounzip  /4th_gen_i5_i7_SINIT_75.BIN
savedefault    0