Virtual memory card controller

• US 7,558,907 B2
• Filed: 10/13/2006
• Issued: 07/07/2009
• Est. Priority Date: 10/13/2006
• Status: Active Grant

• Current Assignee: Cryptolog, Spansion LLC (Infineon Technologies AG)
• Original Assignee: Spansion LLC (Infineon Technologies AG)
• Inventors: Stern, Julien, Colnot, Cedric, Prawitz, Nicolas, Carvounas, Christophe, Grall, Jean-Yves, Pornin, Thomas
• Primary Examiner(s): Verbrugge, Kevin
• Application Number:
  US11/549,551
• Publication Number:
  US 20080091878A1
• Time in Patent Office: 998 Days
• Field of Search: None
• US Class Current: 711/103
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/0643 Management of files
• CPC Class Codes: G06F 3/0661 Format or protocol conversion arrangements
• CPC Class Codes: G06F 3/0664 at device level, e.g. emulation of a storage device or system
• CPC Class Codes: G06F 3/0667 at data level, e.g. file, record or object virtualisation
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]

Abstract

The claimed subject matter can provide an architecture that can transparently provide more robust interactions between a host device and a smartcard or other mass media storage device by way of block level read or write operations provided as part of a standard interface protocol. A virtual controller can be installed on the smartcard to manage access to the data store of a smartcard. The virtual controller can provide special objects (e.g., files, directories, partitions . . . ) to the host, and upon an access to one of these special files, call an application to manage pre- or post-processing of the data transferred between the host and the smartcard.

Claims

1. A system that transparently employs standard read or write operations at a sector level to facilitate interactions between a host and a mass storage block device, comprising:

an interface to a host;

a data store addressable at a sector level; and

a virtual controller component that controls access to the data store and is configured to advertise a special object to a file system employed by the host to facilitate a bi-directional communication socket, wherein the socket is employed to transfer a command that is encapsulated within the socket and transmitted along the interface.

2. The system of claim 1, the virtual controller component is configured to receive an operation associated with the special object and to determine an application to call.

3. The system of claim 2, the virtual controller component determines the application to call based upon at least one of a type of the operation or a type of the special object.

4. The system of claim 2, the operation is a sector level read operation or a sector level write operation.

5. The system of claim 1, the special object is at least one of a special file, a special directory, a special partition, a special file system, or a virtual object.

6. The system of claim 1, the special object is a special file physically extant in the data store.

7. The system of claim 6, the special file has a file size equal to one sector of the file system.

8. The system of claim 6, the special file is created as the data store is formatted.

9. The system of claim 6, the virtual controller component records a logical sector number corresponding to a physical location of the special file.

10. The system of claim 9, the virtual controller component updates the logical sector number when the physical location of the special file is changed.

11. The system of claim 6, the special file is flagged as an unmovable to the file system.

12. The system of claim 6, the special file is created in a special directory.

13. The system of claim 12, the virtual controller component, upon initialization, scans the special directory and records a physical location of the special file.

14. The system of claim 6, the special file is created after initialization and the virtual controller component records a logical sector number corresponding to a physical location of the special file.

15. The system of claim 14, the special file is created as a result of an operation transmitted by the host.

16. The system of claim 1, the special object is a virtual object not extant in the data store.

17. The system of claim 16, the virtual object is dynamically created.

18. The system of claim 16, the virtual object is addressable to the file system as a logical extension of the data store, the logical extension begins at logical sector N, where N is a number of physical sectors in the data store.

19. The system of claim 1, the virtual component comprising:

a file system client that reads data from or writes data to the data store;

a virtual file system that includes a directory registered to a plug-in; and

a file system server that serves the virtual file system to the host.

20. The system of claim 19, the virtual controller component advertises a virtual file system to the host.

21. The system of claim 19, the virtual controller component employs a table to map a sector level operation to a logical path in the virtual file system.

22. The system of claim 21, the virtual controller component is configured to call the plug-in registered to the directory in the logical path with a request for at least one of a directory, a file, or an offset of the file that corresponds to a subpath of the directory.

23. The system of claim 22, the virtual controller component queries the plug-in to determine the special objects over which the plug-in is registered.

24. The system of claim 21, the virtual controller component maintains a special storage block in the data store that is not visible to the host.

25. The system of claim 21, the virtual controller component stores the table in the special storage block.

26. The system of claim 19, the directory is a root directory of the virtual file system and the plug-in is a noop plug-in that forwards an operation received from the host to the data store.

27. The system of claim 19, the plug-in is at least one of a Digital Rights Management (DRM) plug-in, a random plug-in, an encryption plug-in, a multiplexer plug-in, a compression plug-in, or a special plug-in.

28. The system of claim 1, the socket is at least one of an input socket or an output socket, the socket is employed to transfer a command.

29. The system of claim 28, the command is comprised of a device number, a socket number and a payload.

30. The system of claim 28, the ISO command relates to an Application Protocol Data Unit (APDU) command, where APDU is defined by ISO 7816.

31. The system of claim 28, the command is an extension of the ISO command.

32. The system of claim 28, further comprising a file system client included in the VMCC.

33. The system of claim 32, the VMCC pre-processes data received from the input socket prior to writing to the data to the store.

34. The system of claim 32, the VMCC post-processes data received from the data store prior to transmitting the data to the output socket.

35. The system of claim 1, further comprising a mass storage device controller.

36. The system of claim 35, the virtual controller component is a hardware circuit operatively coupled to a mass storage device controller.

37. The system of claim 35, the virtual controller component is a software application that runs on a mass storage device controller.

38. The system of claim 1, the data store is configured as a block device.

39. The system of claim 1, the data store is comprised of flash memory.

40. The system of claim 1, the interface is compliant with at least one of MultiMediaCard (MMC), Secure Digital (SD), or Universal Serial Bus (USB) standards.

41. A computer-implemented method for facilitating interactions between a host and a mass media storage device, comprising:

interfacing a host device with a mass media data storage device;

representing a special object to a file system of the host device;

receiving an access operation relating to the special object; and

instantiating an application associated with the special object based at least in part upon a type of the access operation, wherein the application opens at least one of an input socket or an output socket, the socket is employed to transfer a command that is encapsulated within the socket and transmitted along the interface.