Electronic device having improved security

• US 20080022083A1
• Filed: 07/10/2006
• Published: 01/24/2008
• Est. Priority Date: 07/10/2006
• Status: Active Grant

• Current Assignee: Memjet Technology Ltd. (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia, Funk, David William
• Granted Patent: US 7,934,092 B2
• Time in Patent Office: Days
• US Class Current: 713/1
• CPC Class Codes: G06F 21/57 Certifying or maintaining trusted computer platforms, e.g. secure boots or power-downs, version controls, system software checks, secure updates or assessing vulnerabilities

Abstract

An electronic device comprising an embedded computer system is provided. The device comprises a processor supporting a real-time operating system (RTOS). The processor further supports user and supervisor modes. The computer system is programmed such that only code portions directly controlling essential hardware in the device are run in supervisor mode.

Claims

1. An electronic device comprising an embedded computer system, said device comprising a processor supporting a real-time operating system (RTOS), said processor supporting user and supervisor modes, wherein said computer system is programmed such that only code portions directly controlling essential hardware in said device are run in supervisor mode.

2. The electronic device of claim 1, wherein said computer system is programmed such that code portions not directly controlling essential hardware in said device are run in user mode.

3. The electronic device of claim 1, wherein a core of said real-time operating system (RTOS) runs in user mode.

4. The electronic device of claim 1, wherein said computer system is programmed such that a code portion directly controlling essential hardware is callable from an application running in user mode via a trap identifying said code portion.

5. The electronic device of claim 1, wherein said device is a printer and said essential hardware comprises drive circuitry for actuating nozzle actuators in a printhead.

6. The electronic device of claim 1, wherein said code portion directly controlling essential hardware communicates with at least one authentication chip in said device before an operation of said hardware, said authentication chip authorizing said operation.

7. The electronic device of claim 6, wherein a first authentication chip is associated with a consumable component of said device.

8. The electronic device of claim 7 comprising a plurality of first authentication chips, each one of said first authentication chips being associated with a respective consumable component.

9. The electronic device of claim 8, wherein said device is a printer and said consumable component is an ink cartridge having a respective first authentication chip.

10. The electronic device of claim 9, wherein said authorized operation is selected from:

printing only when an ink cartridge of a predetermined type, as determined via the associated authentication chip, is loaded in said printer; and

printing only when a predetermined amount of ink, as determined via the associated authentication chip, is remaining in the ink cartridge.

11. The electronic device of claim 6, wherein a second authentication chip is positioned in a body of said device.

12. The electronic device of claim 11, wherein said device is a printer and said second authentication chip is mounted in or on a print engine.

13. The electronic device of claim 11, wherein said device is a printer and said authorized operation is selected from:

printing at a predetermined speed;

printing at a predetermined resolution;

full color printing; and

monochrome printing.

14. The electronic device of claim 1, wherein said code portion is programmed to allow only an authorized operation of said hardware.

15. The electronic device of claim 14, wherein said device is a printer and said authorized operation is selected from:

printing at a predetermined speed;

printing at a predetermined resolution;

full color printing; and

monochrome printing.