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

• US 20090037909A1
• 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 Holding 81 LLC (Intellectual Ventures LLC)
• Inventors: Xu, Yongyong
• Granted Patent: US 9,164,787 B2
• Time in Patent Office: Days
• US Class Current: 718/1
• 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

1-54. -54. (canceled)

55. A system for running a guest operating system from a host operating system in a mobile device, the host system supporting a memory protection mechanism to run said guest operating system within the same memory space of said host operating system while preserving the state of said host operating system in memory throughout the execution of said guest operating system, comprising:

a launcher for starting said guest operating system, said launcher going through said memory protection mechanism to mark memory blocks used by said host operating system as protected from said guest operating system;

an exit-code for exiting said guest operating system, said exit-code restoring said state of said host operating system; and

wherein said guest operating system accesses only memory blocks that have not been marked as protected so that said memory blocks marked as protected are preserved throughout the execution of said guest operating system.

56. The method of claim 55, wherein said memory protection mechanism is achieved through a memory management unit (MMU) that allows or disallows a program to access particular memory addresses.

57. The method of claim 55, wherein said launcher is operable to move memory blocks currently used by said host operating system whose address range is needed by said guest operating system to a free memory location in the mobile device and mark said free memory blocks as protected.

58. The method of claim 57, wherein said exit-code is operable to restore said free memory blocks to said memory blocks whose address range is needed by said guest operating system and reverting said free memory blocks.

59. A system for running a guest operating system from a host operating system of a mobile device while keeping the state and data of said host operating system in memory throughout the execution of said guest operating system comprising:

a launcher for moving memory blocks in a lower address space used by said host operating system to free memory blocks in an upper address space and preserving said state and data of said host operating system to said upper address space, identifying a memory address location where memory addresses above said location contain said host operating system data and memory addresses below said memory address location that are free to be used by said guest operating system, and launching said guest operating system by passing said memory address location as a reduced memory size to said guest operating system;

an exit-code for exiting said guest operating system, said exit-code restoring said state of said host operating system; and

wherein said guest operating system runs in said reduced in size memory space and leaves memory space higher than said memory location untouched.

60. The system of claim 59, wherein said launcher is operable to find a free memory block in the upper address space for each of said memory blocks in lower address currently used by said host operating system, and move said used memory block in said lower address space to said free memory block in said upper address space.

61. The system of claim 59, wherein said exit-code is operable to restore the state and data of said host operating system by reverting each of said memory blocks in said lower address space from each of said free memory blocks in said upper address space.

62. The system of claim 59, further comprising a memory detection module of said guest operating system that uses said reduced in size memory space as the total available memory of the mobile device instead of the real memory size of the mobile device.

63. The system of claim 59, wherein said launcher is operable to modify a system register in said mobile device to report said reduced memory size as total available memory to said guest operating system.

64. The system of claim 59, wherein said launcher is operable to generate said reduced memory size by disabling one or more memory banks of said mobile device to make them no longer available to said guest operating system.

65. The system of claim 59, wherein input output (IO) states and registers of said mobile device within said host operating system are preserved and later restored into said free memory block in upper address space.

66. A system for starting a guest operating system from a host operating system of a mobile device within the same memory space of said host operating system while keeping the running state of said host operating system throughout the execution of said guest operating system in place comprising:

a launcher for launching said guest operating system;

a memory device driver of the guest operating system, said memory device driver receiving a list of memory addresses of currently used memory of said host operating system from said launcher during initialization of said guest operating system, said memory device driver claiming said list of memory addresses and keeping them from being modified by any other part of said guest operating system during the execution of said guest operating system;

an exit-code for restoring the state of said host operating system by releasing said list of memory addresses from said device driver; and

wherein said guest operating system runs in the same memory space of said host operating system, with memory used by said host operating system being claimed and protected by said memory device driver.

67. The system of claim 66, wherein said list of memory addresses used by said host operating system includes memory addresses only in dynamic runtime memory of said host operating system.

68. The system of claim 66, wherein said list of memory addresses used by host operating system also includes the current input output (IO) states and current registers of said mobile device.

69. The system of claim 66, wherein said memory device driver is operable to temporarily move a memory block around in order to make said memory block freely available.

70. The system of claim 66, wherein said memory device driver is kernel mode driver.

71. A system for running a guest operating system from a host operating system of a mobile device while keeping the state and data of said host operating system in memory throughout the execution of said guest operating system comprising:

a launcher, said launcher saving an image of memory used by said host operating system to an external memory device; and

an exit-code, said exit-code restoring said host operating system from said external memory device.

72. The system of claim 71, wherein said image of memory used by said host operating system is transferable to another mobile device or emulator and resumed therein.

73. The system of claim 71, wherein saving an image of memory only saves dynamic and runtime memory.

74. The system of claim 71, wherein said saved image of memory be served as a backup point.