System and method for updating contents of a flash ROM

• US 7,017,004 B1
• Filed: 03/29/2002
• Issued: 03/21/2006
• Est. Priority Date: 03/29/2002
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Fortier, Dominique, Chew, Chee H., Calligaro, Michael P., Ramig, Randal James, Lantz, Eric Lawrence Albert
• Primary Examiner(s): Peikari, B. James
• Assistant Examiner(s): Li, Zhuo H.
• Application Number:
  US10/112,243
• Time in Patent Office: 1,453 Days
• Field of Search: 711/147, 711/100, 711102-103, 711/104, 713 1- 2, 713/191, 713/200, 713170-171, 713/176, 713/180, 713/100, 713/155, 713/161, 713164-167, 713/160, 345/745, 365/200, 365/230.01, 365/230.04, 395/497
• US Class Current: 711/102
• CPC Class Codes: G06F 12/0223 User address space allocation, e.g. contiguous or non contiguous base addressing
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 2212/2022 Flash memory

Abstract

Upgrading a non-volatile memory image such as a flash ROM is accomplished by partitioning the flash ROM into a plurality of flash ROM regions. One of the flash ROM regions is selected to receive the software upgrade, which can then be directly overwritten without having to overwrite the flash ROM image in its entirety. Through the use of an image buffer, which stores information about the ROM regions, it is possible to move ROM regions, delete ROM regions, add ROM regions, expand/contact ROM regions, update ROM regions, and enable/disable ROM regions without having to modify the entire ROM image or shadow parts of the ROM image in RAM. Additionally, security and registry information can also be logically linked to a particular region.

Claims

1. In a computer system containing a processor coupled to a non-volatile memory system for storing a non-volatile memory image representing read-only-memory of the computer system, a method for updating the non-volatile memory image with a software update, the method comprising:

processing the software update by the processor to validate the software update, wherein the processor is to execute an operating system;

partitioning the non-volatile memory image into a plurality of non-volatile memory regions, the non-volatile memory regions each potentially having a varying size,

allocating an image buffer for storing an address location, a size, and a purpose for at least a portion of the non-volatile memory regions;

designating a selected non-volatile memory region to receive the software update by identifying an existing non-volatile memory region at least large enough to accommodate the software update or repartitioning a portion of the non-volatile memory image to form a new non-volatile memory region at least large enough to accommodate the software update;

overwriting the selected non-volatile memory region with the software update without having to overwrite the non-volatile memory image in its entirety; and

updating the image buffer such that the address location, the size, and the purpose for the selected non-volatile memory region are current.

2. The method as recited in claim 1, further comprising:

issuing an update interrupt command temporarily preventing the operating system of the computer system from recognizing the plurality of non-volatile memory regions.

3. The method as recited in claim 1, wherein processing the software update by the processor to validate the software update further comprises assigning a security signature to the selected non-volatile memory region;

and verifying whether the software update contains a matching security signature prior to overwriting the selected non-volatile memory region with the software update.

4. The method as recited in claim 1, wherein overwriting the selected non-volatile memory region with the software update further comprises merging registry data associated with the selected non-volatile memory region with registry data associated with the software upgrade.

5. The method as recited in claim 1, wherein at least a portion of the plurality of non-volatile memory regions include execute-in-place files.

6. One or more computer-readable media comprising computer-executable instructions that, when executed, perform the method as recited in claim 1.

7. A method for maintaining a non-volatile memory of a computer system having a processor coupled to the non-volatile memory, the non-volatile memory containing a boot loader, a kernel, an operating system to be executed by the processor and other functional devices, the method comprising:

partitioning the non-volatile memory into a plurality of non-volatile memory regions;

maintaining an image buffer containing an information entry including an address location, a size, and a purpose for at least a portion of the non-volatile memory regions;

updating the image buffer to reflect changes in the address location, the size, and the purpose of at least one of the non-volatile memory regions; and

referencing, by the processor, the image buffer rather than the boot loader and/or kernel to identify the locations of one or more of the non-volatile memory regions.

8. The method as recited in claim 7, wherein the image buffer is a configurable data structure in one of the plurality of non-volatile memory regions.

9. The method as recited in claim 7, further comprising disabling a particular non-volatile memory region from the plurality of non-volatile memory regions by removing at least part of the information entry pertaining to the particular non-volatile memory region from the image buffer.

10. The method as recited in claim 7, further comprising adding an additional non-volatile memory region to the plurality of non-volatile memory regions, by adding an additional information entry pertaining to the additional non-volatile memory region to the image buffer.

11. One or more computer-readable media comprising computer-executable instructions that, when executed, perform the method as recited in claim 7.

12. A method for maintaining a flash ROM in a computer system having a processor, the flash ROM including a kernel, an operation system and other devices, the method comprising:

partitioning the flash ROM into a plurality of flash ROM regions;

storing contents of the kernel, operating systems, and other devices in separate flash ROM regions among the plurality of flash ROM regions;

storing an address location, a size, and a purpose for at least a portion of the plurality of flash ROM regions in an image buffer;

maintaining the image buffer to reflect changes in the address location, the size, and the purpose of at least one of the plurality of flash ROM regions; and

enabling the computer system under control of the operation system to access the other devices stored in the plurality of flash ROM regions by referencing the image buffer, wherein the processor is to execute the operating system.

13. The method as recited in claim 12, further comprising:

(a) receiving a file that contains instructions to update the contents of a particular one of the other devices with updated contents;

(b) disabling the computer system from referencing the image buffer;

(c) booting the computer system;

(d) flashing one of the plurality of flash ROM regions that contains the particular one of the other devices with the updated contents; and

(e) enabling the computer system to reference the image buffer, after completion of the flashing.

14. The method as recited in claim 13, further comprising assigning a digital security signature to at least a portion of the plurality of flash ROM regions and ascertaining whether the file that contains instructions to update the contents of a particular one of the other devices, contains a matching digital security signature.

15. The method as recited in claim 14, further comprising if the file does not contain a matching digital security signature, then rendering inoperative those acts performed in paragraphs (b) through (e).

16. The method as recited in claim 13, wherein the file is an execute-in-place file that contains address locations for the updated contents.

17. One or more computer-readable media comprising computer-executable instructions that, when executed, perform the method as recited in claim 12.

18. A non-volatile memory system, comprising:

a plurality of flash ROMs having a specified address location and size;

each of the flash ROMs containing one or more functional devices;

an image buffer containing address locations, sizes, and purposes for each of the flash ROMs, the image buffer being modifiable to reflect changes in the address locations, the sizes, and the purposes of the flash ROMS; and

an operating system to be executed by a processor coupled to the non-volatile memory system, the operating system being stored in at least one of the of the plurality of flash ROMs, wherein during operation of the system the operating system is to read the image buffer and link the plurality of flash ROMs so that they function together as single ROM image.

19. The system as recited in claim 18, wherein at least a portion of the flash ROMs are separately configurable, whereby if contents of one of at least a portion of the flash ROMs are modified, it is not necessary to overwrite contents of at least one of the other flash ROMs.

20. The system as recited in claim 18, wherein at least a portion of the plurality of flash ROMs contain encrypted security codes preventing unauthorized modifications of the flash ROMs.

21. The system as recited in claim 18, wherein at least a portion of the plurality of flash ROMs are configured to store execute-in-place files.

22. One or more computer-readable media having stored thereon computer executable instructions that, when executed by one or more processors coupled to a non-volatile memory system, causes the one or more processor of a computer system to:

execute an operating system, wherein each of the one or more processors is to selectively execute the operating system;

receive a file used to update an old version of a non-volatile memory image to a new version of a non-volatile memory image, wherein the new version of the non-volatile memory image contains a software update to the old version of the non-volatile memory image, wherein the non-volatile memory image is logically partitioned into a plurality of non-volatile memory regions, the non-volatile memory regions each potentially having a varying size;

allocate an image buffer for storing an address location, a size, and a purpose for at least a portion of the non-volatile memory regions;

process the file by the one or more processors to validate the software update;

designate a selected non-volatile memory regions to receive the software update by identifying an existing non-volatile memory region at least large enough to accommodate the software update or repartitioning a portion of the non-volatile memory image to form a new non-volatile memory region at least large enough to accommodate the software update;

overwrite the selected non-volatile memory region with the software update without having to overwrite the non-volatile memory image int its entirety; and

update the image buffer such that the address location, the size, and the purpose for the selected non-volatile memory region are current.

23. One or more computer-readable media as recited in claim 22, further comprising computer executable instructions that, when executed, direct the computer system to allocate an image buffer containing address locations for each of the plurality of non-volatile memory regions.

24. One or more computer-readable media as recited in claim 22, further comprising computer executable instructions that, when executed, direct the computer system to issue an update interrupt command temporarily preventing the operating system of the computer system from recognizing the plurality of non-volatile memory regions.

25. One or more computer-readable media as recited in claim 22, further comprising computer executable instructions that, when executed, direct the computer system to check whether a security signature embedded in the selected non-volatile memory region matches security signature associated with the software update prior to directing the computer system to overwrite the selected non-volatile memory region with the software update.

26. One or more computer-readable media as recited in claim 22, further comprising computer executable instructions that, when executed, direct the computer system to merge registry data associated with the selected non-volatile memory region with registry data associated with the software upgrade when the computer system is directed to overwrite the selected non-volatile memory region with the software update.

27. One or more computer-readable media having stored thereon computer executable instructions that, when executed by one ore more processors, causes the one or more processors of a computer system to:

partition a non-volatile memory of the computer system into a plurality of non-volatile memory regions each storing a separate one of a boot loader, a kernel, an operating system and other functional devices;

execute the operating system, wherein each of the one or more processors is to selectively execute the operating system;

maintaining an image buffer containing an information entry including an address location, a size, and a purpose for at least a portion of the non-volatile memory regions;

update the address location in the image buffer to reflect changes in the address location, the sizes, and the purpose of at least one of the non-volatile memory regions; and

reference the image buffer rather than the boot loader and/or kernel to identify the locations of one or more of the non-volatile memory regions.

28. One or more computer-readable media as recited in claim 27, further comprising executable instructions that, when executed, direct the computer system to disable a particular non-volatile memory region from the plurality of non-volatile memory regions by removing at least part of the information entry pertaining to the particular non-volatile memory region from the image buffer.

29. One or more computer-readable media as recited in claim 27, further comprising computer executable instructions that, when executed, direct the computer system to add an additional non-volatile memory region to the plurality of non-volatile memory regions, by adding an pertaining to the additional non-volatile memory region in the image buffer.

30. A computer system, comprising:

a processor to execute an operating system,

a configurable memory device containing a plurality of ROMs each containing software contents and potentially having a varying size;

an image buffer for storing an address location, a size, and a purpose for at least a portion of the software contents stored in the configurable memory device; and

ROM update software that when verified and executed by the processor causes;

the software contents in one of the plurality of ROMs to be overwritten by revised software contents without having to overwrite the other of the plurality of ROMs in their entirety; and

the image buffer to be updated to reflect changes in the address location, the size, and the purpose for the software contents overwritten by the revised software contents.

31. The computer system as recited in claim 30, wherein the configurable memory device is a non-volatile memory device.

32. The computer system as recited in claim 30, wherein the configurable memory device is a flash memory device.

33. The computer system as recited in claim 30, wherein the image buffer is configurable such that one or more of the plurality of ROMs can be moved, deleted, and/or expanded by modifying the address locations contained in the image buffer.