Booting and power management

• US 10,223,128 B2
• Filed: 10/04/2016
• Issued: 03/05/2019
• Est. Priority Date: 09/23/2016
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Doshi, Hardik K.
• Primary Examiner(s): Patel, Nitin C
• Application Number:
  US15/285,202
• Publication Number:
  US 20180088961A1
• Time in Patent Office: 882 Days
• Field of Search: None
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3287 by switching off individual functional units in the computer system
• CPC Class Codes: G06F 1/3293 by switching to a less power-consuming processor, e.g. sub-CPU
• CPC Class Codes: G06F 9/4405 Initialisation of multiprocessor systems
• CPC Class Codes: G06F 9/4418 Suspend and resume; Hibernate and awake
• CPC Class Codes: G06F 9/442 Shutdown
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A computing device may comprise a first processor and a secondary processor. The first processor may initiate a power management process transitioning the first processor from a first state to a second state and, upon reaching a predetermined step in the power management process, notify the secondary processor of the power management process. The secondary processor may initiate, in response to the notifying, a parallel power management process transitioning the secondary processor from an equivalent first state to an equivalent second state.

Claims

1. A method for coordinating operations between a first processor and a secondary processor in a device, comprising:

initiating, by the first processor, a power management process transitioning the first processor from a first state to a second state;

notifying, by the first processor, the secondary processor of the power management process upon reaching a predetermined step in the power management process;

initiating, by the secondary processor, a parallel power management process transitioning the secondary processor from an equivalent first state to an equivalent second state in response to the notifying; and

polling, by the first processor, the secondary processor upon reaching a later predetermined step in the power management process and waiting for a status of the secondary processor to satisfy a predefined condition before continuing the power management process.

2. The method of claim 1, wherein the power management process comprises at least one process selected from a group consisting of:

a shutdown process, an enter standby process, a leave standby process, a warm reboot process, an enter sleep process, and a wakeup process.

3. The method of claim 1, wherein the notifying comprises sending data from the first processor to the secondary processor on a bus.

4. The method of claim 1, wherein the notifying comprises placing data in a register of the secondary processor.

5. The method of claim 1, further comprising initializing, by the first processor, a predefined recovery process on the secondary processor in response to detection of an error condition in the secondary processor as determined by the status of the secondary processor.

6. The method of claim 1, wherein the first processor comprises a main processor for the device.

7. The method of claim 1, wherein the secondary processor comprises an auxiliary processor for the device configured to operate one or more device hardware subsystems.

8. A computing device comprising:

a first processor;

a secondary processor; and

a set of instructions, that when executed by a processor selected from a group consisting of the first processor and the secondary processor, causes;

the first processor to initiate a power management process transitioning the first processor from a first state to a second state;

the first processor to notify, upon reaching a predetermined step in the power management process, the secondary processor of the power management process;

the secondary processor to initiate a parallel power management process transitioning the secondary processor from an equivalent first state to an equivalent second state in response to the notifying; and

the first processor to poll, upon reaching a later predetermined step in the power management process, the secondary processor and wait for a status of the secondary processor to satisfy a predefined condition before continuing the power management process.

9. The device of claim 8, wherein the power management process comprises at least one process selected from a group consisting of:

a shutdown process, an enter standby process, a leave standby process, a warm reboot process, an enter sleep process, and a wakeup process.

10. The device of claim 8, wherein the first processor is configured to notify the secondary processor by sending data from the first processor to the secondary processor on a bus.

11. The device of claim 8, wherein the first processor is configured to notify the secondary processor by placing data in a register of the secondary processor.

12. The device of claim 8, wherein the first processor is further configured to initialize, by the first processor, a predefined recovery process on the secondary processor in response to detection of an error condition in the secondary processor as determined by the status of the secondary processor.

13. The device of claim 8, wherein the first processor comprises a main processor for the device.

14. The device of claim 8, wherein the secondary processor comprises an auxiliary processor for the device configured to operate one or more device hardware subsystems.

15. A method for coordinating cold boot operations between a first processor and a secondary processor in a device, the method comprising:

supplying power to the first processor;

supplying power to the secondary processor;

initiating, by the first processor, a boot process;

initializing the secondary processor;

upon reaching a predetermined step in the boot process, transferring, by the first processor, a boot payload to the secondary processor;

initiating, by the secondary processor, a parallel boot process using the boot payload after receipt of the boot payload; and

checking, by the first processor, a progress of the parallel boot process being performed by the secondary processor.

16. The method of claim 15, further comprising sending, by the first processor, a boot command to the secondary processor, wherein the initiating of the parallel boot process is performed in response to receiving the boot command.

17. The method of claim 16, wherein the sending comprises sending data from the first processor to the secondary processor on a bus.

18. The method of claim 16, wherein the sending comprises placing data in a register of the secondary processor.

19. The method of claim 15, wherein:

the boot payload is stored in a memory accessible by the first processor; and

the transferring comprises sending the boot payload to a memory accessible by the secondary processor.

20. The method of claim 15, further comprising initializing, by the first processor, a predefined recovery process on the secondary processor in response to detection of an error condition in the secondary processor resulting from checking the progress of the parallel boot process.

21. The method of claim 15, wherein the first processor comprises a main processor for the device.

22. The method of claim 15, wherein the secondary processor comprises an auxiliary processor for the device configured to operate one or more device hardware subsystems.

23. A computing device comprising:

a first processor;

a secondary processor;

a power supply supplying power to the first processor and the secondary processor; and

a set of instructions, that when executed by a processor selected from a group consisting of the first processor and the secondary processor after power is supplied by the power supply to the first processor and the secondary processor in a cold boot, causes;

the first processor to initiate a boot process;

the secondary processor to initialize;

the first processor to transfer, upon reaching a predetermined step in the boot process, a boot payload to the secondary processor;

the secondary processor to initiate a parallel boot process using the boot payload after receipt of the boot payload; and

the first processor to check a progress of the parallel boot process being performed by the secondary processor.

24. The device of claim 23, wherein the set of instructions further causes the first processor to send a boot command to the secondary processor, wherein the initiating of the parallel boot process is performed in response to receiving the boot command.

25. The device of claim 24, wherein the boot command is sent from the first processor to the secondary processor on a bus.

26. The device of claim 24, wherein the boot command is sent by placing data in a register of the secondary processor.

27. The device of claim 23, wherein:

the boot payload is stored in a memory accessible by the first processor; and

the transferring comprises sending the boot payload to a memory accessible by the secondary processor.

28. The device of claim 23, wherein the set of instructions further causes the first processor to initialize a predefined recovery process on the secondary processor in response to detection of an error condition in the secondary processor resulting from checking the progress of the parallel boot process.

29. The device of claim 23, wherein the first processor comprises a main processor for the device.

30. The device of claim 23, wherein the secondary processor comprises an auxiliary processor for the device configured to operate one or more device hardware subsystems.