Reducing Power-On Time by Simulating Operating System Memory Hot Add

• US 20090287900A1
• Filed: 05/14/2008
• Published: 11/19/2009
• Est. Priority Date: 05/14/2008
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kritt, Barry Alan, Kirscht, Joseph Allen, Kochar, Sumeet, Schwartz, William Bradley
• Granted Patent: US 7,987,336 B2
• Time in Patent Office: Days
• US Class Current: 711/173
• CPC Class Codes: G06F 9/4406 Loading of operating system

Abstract

This invention generally provides a method for speeding up system boot time, by initializing a subset of memory during the system firmware test/initialization, and allowing the system to boot an operating system with this subset of installed memory. While the system is completing the operating system boot with the subset of installed memory, a remainder of the installed system memory is being initialized/tested. When the initialization the remainder of system memory is completed (and after the OS has booted), the SMI handler is invoked. The SMI handler then simulates a physical memory “Hot Add” event, and reports the event to the OS. This allows much of the memory initialization/test activity to occur in parallel with the firmware initialization/test and operating system startup processes.

Claims

1. A computer system comprising:

a memory partitioned into a first region being relatively small as compared to a second region;

a memory controller configured to initialize the first region;

an operating system utilizing the first region upon first region initialization, and;

a System Management Interface (SMI) handler to simulate a physical hot add of the second region to the operating system.

2. The computer system of claim 1 wherein the memory controller begins to initialize the second region upon beginning the initialization of the first region, and wherein the operating system utilizes both the first region and second region upon the simulated physical hot add event.

3. The computer system of claim 2 wherein the operating utilizes the second region as if it were newly added physical memory upon the simulated physical hot add event.

4. The computer system of claim 3 wherein the SMI handler is also configured to adjust a Advanced Configuration and Power Interface (ACPI) table to notify the operating system of the simulated physical hot add event.

5. A method for initializing a computer system comprising:

completing the initializing of a first region of system memory being relatively small as compared to a second region of system memory;

starting initialization for the second region of system memory;

starting a operating system utilizing only the first region of system memory;

simulating a physical hot add of the second region of system memory, and;

allowing the operating system to utilize both the first region of system memory and the second region of system memory.

6. The method of claim 5 wherein the first region is a relatively small amount of the system memory as compared to the second region.

7. The memory of claim 6 wherein simulating a physical hot add of the second region memory is completed only upon the completion of the memory initialization for the second region.

8. The method of claim 7 wherein completing memory initialization for the first region further comprises:

adjusting a Advanced Configuration and Power Interface (ACPI) table to show the first region as being initialized.

9. The method of claim 8 wherein starting memory initialization for the second region further comprises:

generating a System Management Interface (SMI) request upon initialization of the second region.

10. The method of claim 6 wherein a memory controller generates the SMI request.

11. The method of claim 6 wherein simulating a physical hot add of the second region memory is completed by a SMI handler.

12. The method of claim 11 wherein the SMI handler further adjusts the ACPI table and notifies the system operating system of a memory configuration change.

13. A signal bearing medium encoded with instructions, wherein the instruction when executed comprise:

completing the initializing of a first region of system memory;

starting initialization for a second region of system memory;

starting a operating system utilizing only the first region of system memory;

simulating a physical hot add of the second region of system memory, and;

allowing the operating system to utilize both the first region of system memory and the second region of system memory.

14. The signal bearing medium of claim 13 wherein the first region of system memory is a relatively small amount of the system memory as compared to the second region of system memory.

15. The signal bearing medium of claim 14 wherein the simulating a physical hot add is completed only upon the completion of the memory initialization for the second region of system memory.

16. The signal bearing medium of claim 15 wherein the completing the initializing of a first region of system memory comprises:

adjusting a Advanced Configuration and Power Interface (ACPI) table to show the first region as being initialized.

17. The signal bearing medium of claim 15 wherein the starting initialization for a second region of system memory comprises:

generating a System Management Interface (SMI) request upon initialization of the second region of system memory.

18. The signal bearing medium of claim 15 wherein a memory controller is directed to generate the SMI request.

19. The signal bearing medium of claim 15 wherein a SMI handler is directed to simulate a physical hot add of the second region memory.

20. The signal bearing medium of claim 19 wherein the SMI handler is further directed to adjust the ACPI table and notify the operating system of the simulated physical hot add event.