Firmware reverse engineering comes with some unique challenges compared to the reversing of programs that run in the user space of some mainstream operating system. You will encounter one of them before Ghidra’s Code Browser even opens. Let’s illustrate it at a concrete example: I recently got myself some old Cisco devices off eBay as I was curious to have a look at their proprietary IOS operating system. However, when loading the IOS image into Ghidra¹ you are greeted with the following screen: