Range Analysis of Microcontroller Code Using Bit-Level Congruences: 15th International Workshop, FMICS 2010, Antwerp, Belgium, September 20-21, 2010. Proceedings

Verifying the correctness of microcontroller programs in presence of bitwise instructions, loops, and indirect data access poses difficult challenges. In particular, it is necessary to show that an indirect write does not mutate registers, which are indirectly addressable. To prove this property, among others, this paper presents a relational binary-code semantics and details how this can be used to compute program invariants in terms of bit-level congruences. Moreover, it demonstrates how congruences can be combined with intervals to derive accurate ranges, as well as information about strided indirect memory accesses.