Firmware Download for Physical Layer of Peripheral Interface

A method, comprising:

• in response to an indication to boot a computer system that is implemented on one or more co-packaged integrated circuit dies:
• configuring, by a physical interface controller circuit for a physical interface circuit, the physical interface circuit to operate in a first hardware-based mode of a plurality of operating modes;
• loading, from a device coupled to the physical interface circuit, at least a first portion of boot code;
• executing, by a processor circuit of the computer system, the first portion of the boot code, including issuing a request to the physical interface controller circuit to configure the physical interface circuit to enter a second hardware-based mode of the plurality of operating modes;
• and
• loading, from the device, communication firmware into a given one of one or more memory circuits included in the computer system, wherein the communication firmware enables one or more firmware-based modes of the plurality of operating modes.

A system, comprising:

• a computer system implemented on one or more co-packaged integrated circuit dies, the computer system including a peripheral component interconnect express (PCIe) circuit that is configured to operate in a first plurality of modes, including first and second hardware-based modes and at least one firmware-based mode;
• and
• a storage device coupled to the PCIe circuit and configured to support a second plurality of modes including the first and second hardware-based modes;
• wherein the PCIe circuit is configured to:
• based on an indication to boot the computer system, download, from the storage device using the first hardware-based mode, at least a first portion of boot code;
• and
• upon execution of the first portion of the boot code, download, from the storage device using the second hardware-based mode, PCIe firmware into a memory circuit coupled to the PCIe circuit.