Info taken from here: https://gist.github.com/eNV25/c8001491dc0440656ff7b0ae18993ba1?permalink_comment_id=5195795#gistcomment-5195795 Or here: https://gist.github.com/alexey198233/087a1a52d7a31b07bc4e114220561bac

There is one more way. I will explain using the example of the HP Probook 440g6 firmware.

The BIOS downloaded from the HP website is not intended for direct flashing (in my case, this is the R71_012800.bin file). The utilities on the HP_TOOLS section are needed to create the firmware.bin file (add few bytes to the beginning of the file), not for flash. The EFI/HP/BIOS/New path apparently serves only to display information about the firmware, it does not need to be created for flashing (that is why, if you have no HP_TOOLS partition, it complains about the incorrect firmware file size because it is not on the required path ). The firmware itself is created by utilities, copied into the EFI/HP/DEVFW folder and then flashed. The algorithm is as follows:

1. Download exe archive with utilities and the BIOS archive inside.
2. Unpack the archive, run the installation under Wine or VirtualBox.
3. After running the utility, there will be a bunch of errors in the logs about the impossibility of creating a correct firmware.bin file, since there is no full access to the WMI interface, but the firmwareRecovery.bin file will be created - this is the bios file for the firmware. It is created during the launch of HpFirmwareUpdRec and is deleted when it is closed. Minimize HpFirmwareUpdRec, copy the firmwareRecovery.bin file and rename it to firmware.bin
4. Mount the EFI partition and copy firmware.bin to the EFI/HP/DEVFW folder.
5. Reboot, go to bios. The firmware will start automatically when you go to the bios / firmware update section. Before flashing, make sure that the downloaded bios file exactly for your model (the list of supported models you can found in the History.txt file).