Systems, apparatuses and methods may provide for technology that initializes a host-managed device memory (HDM) as a temporary proxy for a system memory, wherein the HDM is associated with an accelerator. The technology also creates a shadow copy of boot firmware code in the HDM and executes one or more boot instructions in the shadow copy of the boot firmware code. In one example, the one or more boot instructions are to be one or more of executed before an initialization of the system memory or executed in parallel with the initialization of the system memory.