On Decompilation of VLIW Executable Files

• http://archive.nbuv.gov.ua/portal/natural/progr/iss/jabout.html

reverse engineering, decompilation, VLIW, Lissom

Machine-code decompilation (i.e. reverse program compilation) is a process often used in reverse engineering. Its task is to transform a platform-specific executable file into a high-level language representation, which is usually the C language. In present, we can find several such tools that support different target architectures (e.g. Intel x86, MIPS, ARM). These architectures can be classified either as RISC (reduced instruction set computing) or CISC (complex instruction set computing). However, none of the existing decompilers support another major architecture type - VLIW (very long instruction word). In this paper, we briefly describe the VLIW architecture together with its unique features and we present several novel approaches how to handle these VLIW-specific features in the decompilation process. We focus on handling of instruction lengths, instruction bundling, and data hazards.