When running objdump command and got error like this:

'''
$ objdump -D out
objdump: out: File format not recognized
'''

Use -b option with value "binary"

'''
$ objdump -b binary -D out

out:     file format binary

objdump: can't disassemble for architecture UNKNOWN!
'''

If you get an error "objdump: can't disassemble for architecture UNKNOWN!" use -m option to specify the architecture

'''
$ objdump -b binary -m i386 -D out
'''