Among the best tools that help create a boot media for installing Windows or a Linux distribution, there is definitely Rufus. It is free (GNU GPLv3 license) and portable software that allows the boot of the system from any type of external media USB. In the article dedicated to Rufus’ tricks and secrets, we saw that the utility allows you to deeply customize the Windows installationsfor example by removing the system requirements checks carried out by the Windows 11 setup.
Rufus It also allows you to prepare bootable media containing a real working installation of Windows. The program supports the function Windows To Goto install and run Windows from a sufficiently fast and powerful USB stick.
What is UEFI validation performed at runtime by Rufus
The new versions of Rufus will integrate a novelty which the developer, the now legendary Pete Batard, has already added to the latest beta of the application, which can be downloaded from this page by clicking on Assets then on the executable indicated as rufus-4.5_BETA.exe.
It’s about the validation of USB support via UEFI, performed at runtime. By checking the box Enable runtime UEFI media validation which appears in the Rufus interface when you click View advanced drive optionsduring the bootable media preparation phase, the application generates a file called md5sum.txtsaved in the root directory of the media.
Inside this file, Rufus notes the MD5 hash of each file on the drive, whether Windows or Linux. The program also prepares an alternative bootloader to the Microsoft one which is loaded first when inserting the USB pendrive when the system is turned on.
The function of runtime UEFI media validation introduced in Rufus, then performs the validation of USB support directly during the system boot process, using UEFI firmware (Unified Extensible Firmware Interface).
Rufus, in essence, becomes able to verify integrity of the USB media before starting the system. An operation that adds an extra level of security and reliability during the boot process.
Why check the integrity of the bootable media
Media based on flash memory, especially cheap USB sticks or SD cards, are prone to failure after the media has been written. Batard highlights the fact that a validation “only one” of the contents at the time of writing (as balenaEtcher and, in part, the Media Creation Tool of Microsoft) would not be sufficient to assure users that their bootable media are fully functional and free from any problems.
The runtime UEFI media validation addition to Rufus proves to be very useful in multiple situations, even if the startup process or installation of the operating system to have restored the degli errors.
By enabling the new feature, the UEFI bootloader provided by Rufus automatically executes the MD5 hash validation of the files present on the medium, based on the information contained in the file md5sum.txt. In case of discrepancies, Rufus displays a boot message to inform the user of the problems encountered with the USB boot media.
At the end of the verification procedure, the Rufus bootloader “passes the ball” to the Microsoft bootloader or the one used by the Linux distro present in the USB drive.
Batard clarifies that the new feature runtime UEFI media validation It is compatible with all versions and editions of Windows as well as with most Penguin distributions.
Opening image credit: Copilot Designer.