Understanding and using COFF

COFF, Common Object File Format, is the formal definition for the structure of machine code files in the UNIX System V.3 environment. All machine-code files—fully linked executables, compiled applications, or system libraries—are COFF files. There is hardly a system-related task that does not require some knowledge of COFF, from understanding assembly source to implementing a proprietary system enhancement. This handbook explains the COFF data structure and its manipulation.

Contents include:

• Basics of COFF.
• Assembly code relocation process.
• COFF file headers.
• Relocation structures.
• Linking.
• The COFF system in UNIX.
• Magic numbers.
• The COFF symbolic debug system.