System boot with external media

Abstract

Various aspects of the present disclosure provide for a system that is able to boot from a variety of media that can be connected to the system, including SPI NOR and SPI NAND memory, universal serial bus (“USB”) devices, and devices attached via PCIe and Ethernet interfaces. When the system is powered on, the system processor is held in a reset mode, while a microcontroller in the system identifies an external device to be booted, and then copies a portion of boot code from the external device to an on-chip memory. The microcontroller can then direct the reset vector to the boot code in the on-chip memory and brings the system processor out of reset. The system processor can execute the boot code in-place on the on-chip memory, which initiates the system memory and the second stage boot loader.

Dependencies are inferred from the claim text.