Abstract: In an example, a system includes a firmware controller to initiate a SM execution mode of the system. The firmware controller scans memory for a process pool tag. The firmware controller compares the process pool tag to a set of operating system process pool tags and detects a coherency discrepancy between the process pool tag and the set of operating system process pool tags. The firmware controller exits the SM execution mode of the system.

Abstract: Example computing devices that are enabled to enter secure operating modes are provided. An example computing device includes a main processor to run an operating system enabled to establish communication from an external device to the main processor via a hardware interrupt handler when the external device is connected to the computing device. The computing device further includes a keyboard controller to detect a lock keystroke sequence at a keyboard, and, in response to detecting the lock keystroke sequence, cause the main processor to halt the operating system and to enter a secure operating mode in which communication from the external device to the main processor via the hardware interrupt handler is blocked.

Abstract: In some examples, executable code causes a processor to execute a first function and enter a system management mode responsive to receipt of a first system management interrupt during the execution of the first function. The executable code causes the processor to pause execution of the first function, save a state of the processor in the system management mode, and exit the system management mode. The executable code causes the processor to execute a second function identified by the first system management interrupt and receive a second system management interrupt to enter the system management mode. The executable code causes the processor to restore the state of the processor in the system management mode and exit the system management mode. The executable code causes the processor to resume execution of the first function after exiting the system management mode.

Abstract: Example computing devices that are enabled to enter secure operating modes are provided. An example computing device includes a main processor to run an operating system enabled to establish communication from an external device to the main processor via a hardware interrupt handler when the external device is connected to the computing device. The computing device further includes a keyboard controller to detect a lock keystroke sequence at a keyboard, and, in response to detecting the lock keystroke sequence, cause the main processor to halt the operating system and to enter a secure operating mode in which communication from the external device to the main processor via the hardware interrupt handler is blocked.

Abstract: In an example, a system includes a firmware controller to initiate a SM execution mode of the system. The firmware controller scans memory for a process pool tag. The firmware controller compares the process pool tag to a set of operating system process pool tags and detects a coherency discrepancy between the process pool tag and the set of operating system process pool tags. The firmware controller exits the SM execution mode of the system.