Optimized UEFI reboot process

• US 10,452,404 B2
• Filed: 07/28/2016
• Issued: 10/22/2019
• Est. Priority Date: 07/28/2016
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Bhimanadhuni, Ramakoti R., Bulusu, Mallik, Ramachandran, Brijesh, Kelly, Bryan D.
• Primary Examiner(s): Rahman, Fahmida
• Application Number:
  US15/222,791
• Publication Number:
  US 20180032349A1
• Time in Patent Office: 1,181 Days
• CPC Class Codes: G06F 3/0604 Improving or facilitating administration, e.g. storage management
• CPC Class Codes: G06F 3/0631 by allocating resources to storage systems
• CPC Class Codes: G06F 3/0632 by initialisation or re-initialisation of storage systems
• CPC Class Codes: G06F 3/0685 Hybrid storage combining heterogeneous device types, e.g. hierarchical storage, hybrid arrays
• CPC Class Codes: G06F 8/65 Updates security arrangements therefor G06F21/57
• CPC Class Codes: G06F 8/654 using techniques specially adapted for alterable solid state memories, e.g. for EEPROM or flash memories
• CPC Class Codes: G06F 9/4401 Bootstrapping security arrangements therefor G06F21/57
• CPC Class Codes: G06F 9/4406 Loading of operating system

Abstract

Systems and methods are disclosed for an initialization process that selectively reloads part or all of the UEFI when called by the operating system. The reload skips platform initialization and enables the selective loading of UEFI modules with tailored dependencies. A special protected region of memory is reserved and is not available for use by the host operating system. Once initialized, the UEFI will use the reserved memory region to execute code that initiates or loads UEFI modules. The host operating system will await the UEFI reload and then re-initialize the functions, structures and variables it receives from the UEFI.

Claims

1. A computer system comprising:

a processor;

a non-volatile memory configured to store a firmware image comprising code used to boot the computer system;

a volatile random-access memory comprising a first reserved region and one or more additional regions available for use by an operating system, wherein the first reserved region comprises an extended memory region that is reserved during an initial system boot but is not used to store code during the initial system boot performed by the firmware image, the first reserved region configured to be available to store code from an updated firmware image following a system reboot; and

instructions executable by the processor to perform a firmware update that comprises a type of reboot with the updated firmware image that reformats the first reserved region while preserving the operating system and application context in the one or more additional regions by skipping memory initialization code in the updated firmware image.

2. The system of claim 1, wherein the first reserved region is designated on the initial system boot for use by Basic Input/Output System (BIOS) code or by system management code.

3. The system of claim 2, further comprising:

a second reserved region in the volatile random-access memory that is designated on the initial system boot for use by BIOS code or by system management code.

4. The system of claim 1, wherein the non-volatile memory is read only memory (ROM) or non-volatile random access memory (NVRAM).

5. A method for booting a computer system, comprising:

configuring computer system hardware using a firmware image stored in non-volatile memory;

configuring a volatile random-access memory to reserve a protected memory area, wherein memory outside the protected memory area is available for use by an operating system, wherein the protected memory area comprises a standard memory region and an extended memory region, and wherein the extended memory region is not used to store code during an initial system boot performed by the firmware image but is configured to be available to store code from an updated firmware image following a system reboot; and

performing a firmware update that comprises a type of reboot with the updated firmware image that reformats the protected memory area while preserving the operating system and application context in the memory outside the protected memory area by skipping memory initialization code in the updated firmware image.

6. The method of claim 5, wherein at least part of the protected memory areas are designated on the initial system boot for use by Basic Input/Output System (BIOS) code or Unified Extensible Firmware Interface (UEFI) code or by system management code.

7. The method of claim 5, further comprising:

replacing the firmware image with the updated firmware image;

rebooting the computer system using the updated firmware image while maintaining an existing operating system context in the volatile random-access memory; and

storing code from the updated firmware image in the extended memory regions of the protected memory areas.

8. The method of claim 7, further comprising:

saving operating system code and data and applications to memory prior to the rebooting; and

waking the operating system code and data and the applications from the memory after rebooting the computer.

9. The method of claim 5, further comprising:

replacing one or more firmware volume sections with the updated firmware image section;

rebooting computer using the updated firmware image while maintaining an existing operating system context in the volatile random-access memory; and

storing code from the updated firmware image in the extended memory regions of the protected memory areas.

10. The method of claim 5, wherein the updated firmware image comprises one or more new firmware volume sections and at least one firmware volume section from a previous firmware image.

11. A method for rebooting a computer system, comprising:

loading an updated firmware image into a protected memory area, wherein the protected memory area comprises an extended memory region that was not used to store code during an initial computer system boot performed by a previous firmware image;

rebooting the computer system using the updated firmware image while maintaining an existing operating system context in regions of volatile random-access memory outside the protected memory area by skipping memory initialization code in the updated firmware image; and

subsequent to the rebooting, storing updated Basic Input/Output System (BIOS) or Unified Extensible Firmware Interface (UEFI) code from the updated firmware image in a reserved memory area that was protected during the initial computer system boot.

12. The method of claim 11, wherein the reserved memory area is an area of the volatile random-access memory that has been protected from use by an operating system.

13. The method of claim 12, wherein the volatile random-access memory comprises a standard memory region and an extended memory region, wherein the extended memory region is not used to store code during the initial computer system boot but is configured to be available to store code in the updated firmware image following a system reboot.

14. The method of claim 11, further comprising:

saving operating system code and data and applications to memory prior to rebooting the computer; and

waking the operating system code and data and the applications from the memory after rebooting the computer.

15. The method of claim 11, wherein the updated firmware image comprises one or more new firmware volume sections and at least one firmware volume section from a prior firmware image.