Permanently Cleaning Inet AB Hardcoded SMBIOS Metadata

Why do we allow resellers to tamper with our hardware's SMBIOS for marketing purposes? After finding Inet AB hardcoded as chassis_vendor in my new workstation, I decided to take full control of the NVRAM.

Here's the method I used to permanently erase their metadata and restore the correct ASUS information - without compromising BIOS integrity.

• Download AMIDEFIx64.efi.zip here

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This is a classic OEM behavior - Inet builds the computer and before sending it off they use a DMI editing tool from American Megatrends (AMI) to burn their own “System Manufacturer”string directly into the motherboard's NVRAM/SMBIOS table.

The reason it remains is that the default BIOS flash utility (Asus EZ Flash) is designed to keep the DMI block intact, otherwise the motherboard serial number, UUID, and Mac addresses would have been deleted with each update.

Since Linux reads the DMI table extremely early in the boot phase, it is not possible to mask this via a simple cmdline parameter. You have to overwrite the table at the hardware level, and you do it with the same type of tool that Inet AB used.

Permanently change the DMI table in EFI

You need a tool called AMIDEFIx64.efi (AMI DMI Editor for EFI). It often circulates online in packages such as AMI Aptio V DMI Edit tools.

Place the tool: Download AMIDEFIx64.efi and put the file directly in the root of your EFI partition (the same partition where you have your cores).

Boot an EFI Shell

If you do not already have an EFI shell, you can find it in /usr/share/edk2/OvmfX64/Shell.efi (Gentoo Linux) or from e.g. from TianoCore and put it on the partition. You can boot it directly via your current efibootmgr setup or from the BIOS boot menu.

Change the strings

Once inside the EFI shells, navigate to your disk (usually FS0: or FS1:) and run the following commands to restore Asus original strings

Change System Manufacturer from Inet_AB to Asus

AMIDEFIx64.efi /SM "ASUSTeK COMPUTER INC."

As a bonus, right now it probably says System Product Name in your dmesg (which is the default when Inet AB missed setting it). You can correct it too

AMIDEFIx64.efi /SP "PRIME A620AM-K"

Inet AB

So where do we find Inet_AB and where have they placed their advertising?

First of all, we find it in bioset systems, i.e. id you can either find it in these several ways

We can find it in chassis_vendor directory for dmi

grep Inet_AB /sys/class/dmi/id/chassis_vendor 
Inet_AB

We can find it in sys_vendor inside dmi directory

grep Inet_AB /sys/class/dmi/id/chassis_vendor 
Inet_AB

We can find it in sys_vendor insidie dmi directory

grep Inet_AB /sys/class/dmi/id/chassis_vendor 
Inet_AB

We also can find it in modalias inside dmi directory

grep Inet_AB /sys/class/dmi/id/modalias
dmi:bvnAmericanMegatrendsInc.:bvr3827:bd02/05/2026:br38.27:svnInet_AB:pnSystemProductName:pvrSystemVersion:rvnASUSTeKCOMPUTERINC.:rnPRIMEA620AM-K:rvrRev1.xx:cvnInet_AB:ct3:cvrDefaultstring:skuSKU:pfaTobefilledbyO.E.M.:

We can find it via dmidecode -t system

dmidecode -t system|grep -i Inet
Manufacturer: Inet_AB

How To Grub Method

Download AMIDEFIx64.efi.zip from above of this page and move the AMIDEFIx64.efi folder into /boot/efi.

Once you downloaded and unzipped the AMIDEFIx64.efi file run below command

cat /etc/grub.d/40_custom 
#!/bin/sh
exec tail -n +3 $0
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the 'exec tail' line above.

menuentry "Flash BIOS (AMIDEFI)" {
    insmod part_gpt
    insmod fat
    search --no-floppy --fs-uuid --set=root 525cbfeb-c4bb-43c9-9070-75931eb00100
    chainloader /EFI/AMIDEFIx64.efi/efi/boot/BOOTX64.efi
}

Update grub

grub-mkconfig -o /boot/grub/grub.cfg

Reboot the PC

Hit <F8> for enter Startup Menu and choose the grub setup 

Inside grub

Press enter on `Flash BIOS (AMIDEFI)`

You will see an error message about portage but you can ignore this warning

Screenshots

Main Direcotry

• Hit fs0: to enter the correct directory

ChgLogo.efi is from Lenovo

Set System Manufacturer value

Set System Product value

Set System Version value

Set System Manufacturer value

Set Chassis Version value

Set System Family value

Set Chassis Serial Number value

Result

Here is the result after we updated as above pictures shown

Here is the end result

Help

Help Picture 1

Help Picture 2

Help Picture 3

Help Picture 4

• Happy Hacking!