Software management systems and methods for automotive computing devices

• US 7,000,075 B2
• Filed: 06/03/2004
• Issued: 02/14/2006
• Est. Priority Date: 12/20/2000
• Status: Expired due to Term

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Drasnin, Sharon, Radko, Ronald Otto, Beckert, Richard Dennis
• Primary Examiner(s): BRAGDON, REGINALD GLENWOOD
• Application Number:
  US10/860,880
• Publication Number:
  US 20040221096A1
• Time in Patent Office: 621 Days
• Field of Search: 711/207, 711/206, 711/103, 711/104, 711/105, 711/159, 711/160
• US Class Current: 711/133
• CPC Class Codes: G06F 11/1441 Resetting or repowering
• CPC Class Codes: G06F 11/2015 Redundant power supplies power supply failure G06F1/30
• CPC Class Codes: G06F 12/08 in hierarchically structured memory systems, e.g. virtual memory systems
• CPC Class Codes: G06F 12/1009 using page tables, e.g. page table structures
• CPC Class Codes: G06F 12/1027 using associative or pseudo-associative address translation means, e.g. translation look-aside buffer [TLB]
• CPC Class Codes: G06F 12/122 of the least frequently used [LFU] type, e.g. with individual count value
• CPC Class Codes: G06F 2212/2022 Flash memory

Abstract

Methods and systems for operating automotive computing devices are described. In one embodiment, an automotive computing device is provided having a processor, volatile memory, non-volatile memory, and SRAM. An object store is provided for the computing device in the non-volatile memory. One or more pages from the object store are maintained in the SRAM.

Claims

1. A method comprising:

providing an automotive computing device having a processor, volatile memory, non-volatile memory, and SRAM;

providing an object store for the computing device in the non-volatile memory;

maintaining one or more pages from the object store in the SRAM; and

providing pages from the SRAM into the non-volatile memory in a predetermined manner based upon a frequency that said pages are written to said non-volatile memory, wherein said frequency is tracked based on a write count stored in an object store page table.

2. The method of claim 1, wherein said maintaining is performed responsive to a detected power loss.

3. The method of claim 1 further comprising paging object store pages on demand into volatile memory.

4. The method of claim 1 further comprising writing one or more pages from volatile memory into SRAM.

5. The method of claim 4, wherein said writing comprises doing so responsive to accessing a page for the purpose of writing to the page.

6. The method of claim 1 further comprising writing one or more pages from volatile memory into a DRAM buffer allocated for that purpose.

7. The method of claim 1, wherein said providing of the object store comprises copying the object store into the non-volatile memory on an initial boot up of the device.

8. The method of claim 1, wherein the non-volatile memory comprises flash memory.

9. The method of claim 1 further comprising maintaining the object store page table in SRAM, the object store page table providing data associated with the location of object store pages.

10. The method of claim 9 further comprising updating the object store page table in SRAM whenever an object store page is moved from one medium to another.

11. The method of claim 1 further comprising maintaining the object store page table in DRAM, the object store page table providing data associated with the location of object store pages.

12. The method of claim 1 further comprising battery-backing the SRAM in the event of a power loss.

13. In an automotive computing device having non-volatile storage that can contain a system object store and DRAM that can receive object store pages, a method comprising:

providing one or more object store pages from the DRAM into an SRAM or separate DRAM buffer, comprising part of the automotive computing device; and

providing one or more pages from the SRAM or DRAM buffer into the non-volatile storage in a predetermined manner based upon a frequency that said pages are written to said non-volatile storage, wherein said frequency is tracked based on a write count stored in an object store page table.

14. The method of claim 13, wherein said acts of providing comprise doing so using virtual addressing techniques.

15. The method of claim 13 further comprising paging object store pages from the non-volatile storage into DRAM responsive to a page being accessed.

16. The method of claim 15, wherein the non-volatile storage comprises flash memory.

17. The method of claim 15, wherein said paging comprises determining whether a page that is attempted to be accessed is already in DRAM or SRAM, and if not in either, paging it in from the non-volatile memory.

18. The method of claim 17 further comprising updating a translation look-aside buffer to contain a new mapping for a virtual address of at least one page that has been paged in.

19. The method of claim 13 further comprising maintaining the object store page table in the SRAM, or a region of the DRAM buffer that can be backed up to non volatile memory on shutdown, the object store page table maintaining information associated with the location of object store pages.

20. The method of claim 19 further comprising updating one or more entries in the object store page table responsive to said acts of providing.

21. The method of claim 19 further comprising using the object store page table to track the object store pages across power cycles.

22. One or more computer-readable media having computer-readable instructions thereon which, when executed by a computer, implements the method of claim 13.

23. A method comprising:

maintaining, in an automotive computing device, multiple object store pages in device SRAM; and

periodically flushing one or more object store pages to device non-volatile memory to make room for additional object store pages wherein pages that are least frequently written to said non-volatile memory will be flushed first, the least frequently written pages determined based on a write count stored in an object store page table.

24. The method of claim 23 further comprising determining when to flush pages as a function of how many free SRAM pages are available.

25. A method of operating an automotive computing device comprising:

providing an automotive computing device having a processor, volatile memory, non-volatile memory, and SRAM;

providing an object store for the computing device in the non-volatile memory;

maintaining one or more pages from the object store in the SRAM responsive to a detected power loss;

battery-backing the SRAM in the event of a power loss; and

providing pages from the SRAM into the non-volatile memory in a predetermined manner based upon a frequency that said pages are written to said non-volatile memory, wherein said frequency is tracked based on a write count stored in an object store page table.

26. The method of claim 25, further comprising writing one or more pages from volatile memory into SRAM responsive to accessing a page for the purpose of writing to the page.

27. The method of claim 25 further comprising maintaining the object store page table in SRAM, the object store page table providing data associated with the location of object store pages.

28. The method of claim 27 further comprising updating the object store page table in SRAM whenever an object store page is moved from one medium to another.