A (binary file) is a low-level, exact copy of the firmware that resides on the motherboard's SPI flash memory chip. For the EliteBook 840 G5, this file contains:

The downloaded .exe file is a wrapper. You can extract the raw .bin file using these methods: Where to download old BIOS version for EliteBook 840 G5

This is the standard method for unbricking a laptop:

: Modifying the BIOS binary may void warranties, violate software licenses, or render the device permanently inoperable. This paper is for educational and authorized repair purposes only.

Official BIOS updates from HP are typically distributed as .exe SoftPaqs. To get the actual .bin file for a programmer (like a CH341A), you must extract it: