Here is a detailed breakdown of how both mechanisms work under the hood:
Both Intel TXT and AMD SVM/SKINIT solve the same fundamental problem: how do you establish a clean, verifiable trust anchor after the system has already booted, without having to power cycle? A Dynamic Launch is achieved with a lightweight processor bootstrap initiated through a CPU instruction. An important function of x86 Late Launch CPU instructions is that they "measure" the execution code provided for the launch — accomplished by taking a cryptographic hash using an algorithm supported by the TPM so that it may store the measurement within one of the TPM's Platform Configuration Registers (PCR). This initial measurement, referred to as the Core Root of Trust Measurement (CRTM), is the trust anchor for the DRTM.
While they share the same goal, the two implementations are architecturally quite different.