Split file system

• US 6,219,677 B1
• Filed: 05/01/1998
• Issued: 04/17/2001
• Est. Priority Date: 05/01/1998
• Status: Expired due to Term

• Current Assignee: Panasonic Electric Works Company Limited (Panasonic Holdings Corporation)
• Original Assignee: emWare, Inc. (Panasonic Holdings Corporation)
• Inventors: Howard, Michael L.
• Primary Examiner(s): HO, RUAY L
• Application Number:
  US09/071,091
• Time in Patent Office: 1,082 Days
• Field of Search: 707/1, 707/5, 707/10, 707/100-104, 707/200-206, 707/511, 707/506, 707/507, 707/530, 711/111, 364/282.1, 364/283.3, 364/283.4, 348/460, 348/467, 348/473
• US Class Current: 1/1
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: Y10S 707/99953 Recoverability
• CPC Class Codes: Y10S 707/99956 File allocation

Abstract

A file system for a collection of data files on a microcontroller-based device, the microcontroller-based device including an arithmetic/logic unit, read/write memory, and program memory, and the file system comprising a data table stored in the program memory and a document table of contents stored on a host computer. The data table is a set of data files, and the document table of contents includes length and offset information for each data file. A method is also described for creating and managing a file system for a collection of data files on a microcontroller-based device, wherein the microcontroller-based device includes an arithmetic/logic unit, read/write memory, and program memory, wherein the method comprises the steps of providing a data table for storage in the program memory and providing a document table of contents for storage on a host computer.

Claims

1. A split file system for a collection of data files on a microcontroller-based device, the split file system being implemented on a host computer and the microcontroller-based device, the microcontroller-based device including:

an arithmetic/logic unit;

read/write memory; and

program memory;

wherein the split file system comprises;

a data table stored in the program memory of the microcontroller-based device; and

a document table of contents stored on the host computer, wherein the host computer is in electronic communication with the microcontroller-based device and wherein the host computer and the microcontroller-based device are separate systems.

2. The file system in accordance with claim 1, wherein the data table is a set of data files, and the document table of contents includes length and offset information for each data file.

3. The file system in accordance with claim 2, wherein the set of data files is a concatenated set of compressed data files.

4. The file system in accordance with claim 2, further comprising:

means for accessing the document table of contents on the host computer to retrieve the length and offset information; and

means for retrieving the desired data file using the retrieved length and offset information.

5. The file system in accordance with claim 1, wherein at least one of the collection of data files is a rich text document.

6. The file system in accordance with claim 5, wherein the rich text document is an HTML document.

7. A method for creating and managing a split file system for a collection of data files on a microcontroller-based device, the split file system being implemented on a host computer and the microcontroller-based device, wherein the microcontroller-based device includes:

an arithmetic/logic unit;

read/write memory; and

program memory;

wherein the method comprises the steps of;

(a) providing a data table for storage in the program memory of the microcontroller-based device; and

(b) providing a document table of contents for storage on the host computer, wherein the host computer is in electronic communication with the microcontroller-based device and wherein the host computer and the microcontroller-based device are separate systems.

8. The method in accordance with claim 7, wherein the step of providing a data table further comprises the steps of:

(a) compressing each file in a set of desired files; and

(b) concatenating the compressed files to form the data table.

9. The method in accordance with claim 7, wherein the document table of contents includes file length and file offset information.

10. The method in accordance with claim 9, wherein a desired file is accessed by the steps of:

(a) retrieving length and offset information relating to the desired data file from the document table of contents on the host computer; and

(b) accessing the desired data file in the program memory using the retrieved length and offset information.

11. A split file system having software components distributed over a computer network, wherein one element of the computer network is a microcontroller-based device including:

an arithmetic/logic unit;

read/write memory;

program memory; and

non-volatile memory; and

another element of the computer network is a host computer system, wherein the host computer system is in electronic communication with the microcontroller-based device through the computer network and wherein the host computer system and the microcontroller-based device are separate systems, the split file system comprising;

a collection of data files stored in the non-volatile memory of the microcontroller-based device;

byte-oriented non-volatile memory access routines stored in the program memory of the microcontroller-based device; and

file-oriented access routines stored on the host computer, the file-oriented access routines using the computer network to invoke the byte-oriented access routines of the microcontroller-based device;

wherein the file-oriented access routines provide directory and file manipulation capability for the data files stored in the non-volatile memory of the microcontroller-based device.

12. The file system in accordance with claim 11, wherein the data files in the non-volatile memory of the microcontroller-based device are configured as an array of writable blocks.

13. The file system in accordance with claim 11, wherein the memory access routines comprise:

a read routine that reads a range of memory locations from the non-volatile memory; and

a write routine that writes to a single memory location.

14. The file system in accordance with claim 13, wherein a start address and a number of memory locations to be read are passed to the read routine as parameters.

15. The file system in accordance with claim 13, wherein a memory address and a value to be written are passed to the write routine as parameters.

16. A method for creating and managing a split file system having software components distributed over a computer network, wherein one element of the computer network is a microcontroller-based device including:

an arithmetic/logic unit;

read/write memory;

program memory; and

non-volatile memory;

and another element of the computer network is a host computer system, wherein the host computer system is in electronic communication with the microcontroller-based device through the computer network and wherein the host computer system and the microcontroller-based device are separate systems, the method comprising the steps of;

(a) providing a collection of data files stored in the non-volatile memory of the microcontroller-based device;

(b) providing byte-oriented non-volatile memory access routines stored in the program memory of the microcontroller-based device; and

(c) providing file-oriented access routines stored on the host computer, the file-oriented access routines using the computer network to invoke the byte-oriented access routines of the microcontroller-based device.

17. The method in accordance with claim 16, wherein the collection of data files stored in the non-volatile memory of the microcontroller-based device is a collection of compressed data files.

18. A method for maintaining a split file system for one or more files stored in non-volatile memory of a microcontroller-based device, wherein the microcontroller-based device is in communication with a host computer over a computer network, wherein the host computer and the microcontroller-based device are separate systems, the method comprising the steps of:

(a) providing byte-oriented non-volatile memory access routines stored in the program memory of the microcontroller-based device;

(b) providing, on the host computer, file-oriented access routines, the file-oriented access routines using the computer network to invoke the byte-oriented access routines of the microcontroller-based device; and

(c) maintaining, on the host computer, a directory and a free block list characterizing the files stored on the microcontroller-based device and the file storage space available.

19. The method in accordance with claim 18, wherein updating a file stored on the microcontroller-based device further includes the steps of:

(d) maintaining, on the host computer, a copy of the file to be updated;

(e) compressing the copy of the file;

(f) determining file length;

(g) examining the free block list to determine whether number of block required for file storage has changed; and

, if so

(h) modifying the free block list to reflect new block allocation;

(i) storing the file in blocks as allocated in the free block list;

(j) updating a directory entry corresponding to the file being updated; and

(k) writing the file to the microcontroller-based device utilizing the byte-oriented access routines in the program memory of the microcontroller-based device.

20. The method in accordance with claim 19, further comprising the step of updating a transaction counter stored both on the microcontroller-based device and on the host computer.

21. A split file system being distributed between a host computer system and a microcontroller-based device, the split file system comprising:

a data table stored in memory of the microcontroller-based device; and

a software module on the host computer system, wherein the host computer system is in electronic communication with the microcontroller-based device, wherein the host computer system and the microcontroller-based device are separate systems, and wherein the software module interprets the data table.

22. The file system of claim 21, wherein the table is grouped into logical blocks of data.

23. The file system of claim 22, wherein the logical blocks comprise an arrangement including:

a directory structure;

a free block list; and

sequences of blocks that store contents of a file.