Abstract: Systems and methods to support system management mode (SMM) update and telemetry in runtime for bare metal deployments. During runtime operation of a host operating system on a bare metal platform having a management controller and including a processing unit on which the host operating system (OS) and host BIOS are executed, an out-of-band runtime update is performed to update secure execution mode (e.g., SMM) runtime firmware for the bare metal platform using an out-of-band channel comprising an interrupt driven, shared memory-based data exchange channel between the management controller and the host BIOS. This enables secure execution mode runtime firmware to be updated without during runtime without having to reboot the platform or restart the OS kernel. The out-of-band channel also supports exchange of telemetry data logged by the host BIOS during the runtime update with the management controller.