Isolated Execution Environments (IEEs), such as ARM TrustZone and Intel SGX, offer the possibility to execute sensitive code in isolation from other malicious programs, running on the same machine, or a potentially corrupted OS. A key feature of IEEs is the ability to produce reports binding cryptographically a message to the program that produced it, typically ensuring that this message is the result of the given program running on an IEE. We present a symbolic model for specifying and verifying applications that make use of such features. For this we introduce the S$\ell$APIC process calculus, that allows to reason about reports issued at given locations. We also provide tool support, extending the SAPIC/TAMARIN toolchain and demonstrate the applicability of our framework on several examples implementing secure outsourced computation (SOC), a secure licensing protocol and a one-time password protocol that all rely on such IEEs.