What is `bfdname` referred by objcopy manpage?

[Nick Clifton]

Hi Guys,

>> The manpage of objcopy says:
>>
>> -O bfdname
>> --output-target=bfdname
>> 	Write the output file using the object format bfdname.
>>
>> I have no idea what is bfdname.

It would probably be clearer if we used "<target>" here, or maybe "<supported 
target type>".  That way the connection with the last few lines of the --help 
output would be more obvious.

>> Even if I often use `mips-elf-objcopy -O binary a.exe a.bin`, I don't know
>> what is the exact meaning of -O binary 

In this context "binary" is an unfortunate choice of name since it refers to a 
file format called "binary" which is designed to be very simple and space 
efficient, so that it is often used in embedded devices.  It does not 
necessarily mean that the contents of the data in such files can only be 
executables; it is also possible for them to contain data and text.

So the "-O binary" command line switch does not mean "convert the input file 
into the binary numbering system".  The input is already in the binary 
numbering system (as is everything in computers).  It means "convert the input 
file from its current file format into the file format called 'binary'".

Cheers
   Nick