Sometimes it is desired to link in a binary file for example as an array initializer. For this, objcopy can be utilized, with the binary file as an input and for example elf as output format, placing the data into a single, explicitly named section. The architecture of output file can be explicitly set using the -B switch. That possibility is constrained explicitly to binary input files, for other input formats, the diagnostics "Warning: input target 'binary' required for binary architecture parameter." is output and the switch is subsequently ignored. However, the binary file might might come in a "nearly-binary" format, such as intelhex. While it is always possible to convert such format into "pure" binary, it would be nice if objcopy would allow to use the -B switch with intelhex and similar input formats directly.
You didn't mention which version you are using. This is fixed in the binutils 2.21 release. Thanks for the bug report.
Indeed. I used an older version (basically by mistake as I intended to test multiple versions). Checking with version 2.21 shows it works as advertised :-) My apologies and thanks.