Embedded platforms with heterogeneous architecture, considered in this paper, consist of one primary and one or more secondary processors. Development of software systems for these platforms poses substantial difficulties, requiring a distinct set of tools for each constituent of the heterogeneous system. It also makes achieving high efficiency the more difficult task. Moreover, many use cases of embedded systems require runtime configuration, that cannot be easily achieved with usual approaches. This work presents a C-like metaprogramming DSL and a library that provides a unified interface for programming secondary processors of heterogeneous systems with this DSL. Together they help to resolve aforementioned problems. The DSL is embedded in C++ and allows to freely manipulate its expressions and thus embodies the idea of generative programming, when the expressive power of high-level C++ language is used to compose pieces of low-level DSL code. Together with other features, such as generic DSL functions, it makes the DSL a flexible and powerful tool for dynamic code generation. The approach behind the library is dynamic compilation: the DSL is translated to LLVM IR and then compiled to native executable code at runtime. It opens a possibility of dynamic code optimizations, e.g. runtime function specialization for specific parameters known only at runtime. Flexible library architecture allows simple extensibility to any target platform supported by LLVM. At the end of the paper a system approbation on different platforms and a demonstration of dynamic optimizations capability are presented.