>>Can I use axf file for production?
Yes, but read below.
>>I mean can I programme axf file in my devices at the time of production?
The .axf is the same as a .elf. The answer depends on your manufacturing process. And if your programmer supports that format. Most common formats are Intel Hex, binary or S19 files (See MCUXpresso IDE: S-Record, Intel Hex and Binary Files | MCU on Eclipse and MCUXpresso IDE: S-Record, Intel Hex and Binary Files | MCU on Eclipse).
>>Is it safe?
Depends what you mean with 'safe' in this context or why this topic would be related to functional safety?
Keep in mind that using the .axf/.elf file contains much more information than needed for production programming. So by default it contains a lot of information about your application (variables, names, symbol information) which is needed by the debugger, but not for a production programmer. So if you are concerned about reverse engineering your application, you better to not not pass the .elf/.axf to someone else.
I hope this helps,
Erich
