Methods and Systems for Running Multiple Operating Systems in a Single Mobile Device

• US 20090037649A1
• Filed: 08/28/2008
• Published: 02/05/2009
• Est. Priority Date: 07/07/2004
• Status: Active Grant

• Current Assignee: Intellectual Ventures Holding 81 LLC (Intellectual Ventures LLC)
• Original Assignee: Intellectual Ventures Fund 63 LLC (Intellectual Ventures LLC)
• Inventors: Xu, Yongyong
• Granted Patent: US 8,090,938 B2
• Time in Patent Office: Days
• US Class Current: 711/103
• CPC Class Codes: G06F 11/1446 Point-in-time backing up or restoration of persistent data
• CPC Class Codes: G06F 11/1469 Backup restoration techniques
• CPC Class Codes: G06F 12/14 Protection against unauthorised use of memory or access to memory
• CPC Class Codes: G06F 9/4401 Bootstrapping security arrangements therefor G06F21/57
• CPC Class Codes: G06F 9/4406 Loading of operating system
• CPC Class Codes: G06F 9/441 Multiboot arrangements, i.e. selecting an operating system to be loaded
• CPC Class Codes: G06F 9/45545 Guest-host, i.e. hypervisor is an application program itself, e.g. VirtualBox
• CPC Class Codes: G06F 9/544 Buffers; Shared memory; Pipes

Abstract

Methods and systems for running multiple operating systems in a single embedded or mobile device (include PDA, cellular phone and other devices) are disclosed. The invention allows a mobile device that normally can only run a single operating system to run another operating system while preserving the state and data of the original operating system. Guest OS is packaged into special format recognizable by the host OS that still can be executed in place by the system. The Methods include: Change the memory protection bits for the original OS; Fake a reduced physical memory space for guest OS; Use special memory device driver to claim memories of host OS; Backup whole image of the current OS and data to external memory card.

Claims

1. A method for preserving the state and data of an operating system of a mobile device comprising the steps of:

saving the state and data of said operating system;

performing other operations on the mobile device; and

restoring the state and data of said operating system following the performance of said operations.

2. The method of claim 1, wherein saving the state and data of said operating system comprises manipulating memory protection bits for pages of a mobile device memory.

3. The method of claim 2, wherein manipulating memory protection bits for pages of said mobile device memory comprises changing attributes of said pages of said mobile device memory from read/write to read-only.

4. The method of claim 2, wherein manipulating memory protection bits for pages of said mobile device memory comprises making said pages of said mobile device memory inaccessible.

5. The method of claim 1, wherein saving the state and data of said operating system comprises copying and moving said state and data from a lower memory address space to an upper address space and faking a reduced memory environment.

6. The method of claim 5, wherein restoring the state and data of said operating system following the performance of said operations comprises reverting said state and data from said upper address space to said lower address space and restoring said reduced memory environment to a previous memory environment

7. The method of claim 5, wherein faking said reduced memory environment comprises modifying a system register to report said reduced memory environment.

8. The method of claim 5, wherein faking said reduced memory environment comprises changing a memory detection module to use said reduced memory environment.

9. The method of claim 5, wherein faking said reduced memory environment comprises generating said reduced memory environment by disabling one or more memory banks to make them invisible.

10. The method of claim 1, wherein saving the state and data of said operating system comprises using a memory device driver to claim memory blocks containing said state and data of said operating system.

11. The method of claim 10, wherein claiming memory blocks containing said state and data of said operating system comprises making said memory blocks un-modifiable.

12. The method of claim 10, wherein claiming memory blocks containing said state and data of said operating system comprises making said memory blocks inaccessible.

13. The method of claim 10, wherein the memory device driver is a kernel mode driver that prevents said claimed memory blocks from being used by both kernel and user space processes.

14. The method of claim 1, wherein saving the state and data of said operating system comprises backing up said state and data of said operating system to an external memory card.

15. The method of claim 14, wherein said external memory card is selected from a group consisting of a Compact Flash (CF) memory card, a Secure Digital (SD) memory card, and an MMC card.

16. The method of claim 1, wherein said state and data of said operating system comprise a current input/output (IO) state and current registers of said mobile device.

17. A system for preserving the state and data of an operating system of a mobile device comprising:

a means for saving the state and data of said operating system;

a means for performing other operations on the mobile device; and

a means for restoring the state and data of said operating system following the performance of said operations.

18. The system of claim 17, wherein said system is a mobile operating system component.

19. A mobile device capable of preserving the state and data of an operating system running on said mobile device comprising:

a means for saving the state and data of said operating system;

a means for performing other operations on the mobile device; and

a means for restoring the state and data of said operating system following the performance of said operations.

20. The device of claim 19, wherein said device is selected from a group consisting of a PDA, a handheld device, a cellular phone, and an embedded device.