Patent ID: 7581037

Claim:
A method, comprising: receiving, by a processor, a call while the processor is operating in a first mode, wherein the call is made to effect execution of device code to control an Input/Output (I/O) device, wherein the device code is implemented in a non-volatile memory in the I/O device; loading second mode instructions into a protected second mode section of a computer memory; loading the device code from the non-volatile memory in the I/O device into the second mode section of the computer memory, wherein the device code is executed from the second mode section to the computer memory by the processor operating in the second mode; determining, by the processor, whether the call is intended to change a processor operating mode from the first mode to a second mode; selectively changing the state of the processor to the second mode in which the processor executes second mode instructions loaded in the protected second mode section of the computer memory, wherein the second mode section of the computer memory is inaccessible to an operating system, in response to determining that the call is intended to change the processor operating mode; and executing, by the second mode instructions, the device code to control the I/O device.