Why use opdis instead of objdump?
The GNU objdump(1) utility is intended to examine the output of the gcc compiler and the utilities in the GNU binutils distribution. It cannot be used when examining file formats not supported by BFD (e.g. ROM images), and its disassembly options are limited. The opdis utility is intended to complement objdump by providing a simple disassembler for object code. Features which distinguish opdis from objdump include: • the ability to disassemble from an arbitrary starting point in a file • the ability to disassemble a string of hex bytes (e.g. shellcode) • a disassembly algorithm that follows control flow in the target • support for custom output formats via a printf-style format string The intended audience for opdis includes embedded system developers working with ROM images, security personnel examining shellcode strings, and software developers reverse engineering hostile or non-BFD-compliant binaries.
