Mechanism to Change Firmware in a High Availability Single Processor System

• US 20080215915A1
• Filed: 06/28/2007
• Published: 09/04/2008
• Est. Priority Date: 10/29/2002
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Brocade Communications Systems, Inc. (Broadcom, Inc.)
• Inventors: ZHOU, Bill J., HAMMONS, Richard L.
• Granted Patent: US 8,375,363 B2
• Time in Patent Office: Days
• US Class Current: 714/15
• CPC Class Codes: G06F 8/656 while running

Abstract

A “high availability” system comprises multiple switches under the control of a control processor (“CP”). The firmware executing on the processor can be changed when desired. Consistent with the high availability nature of the system (i.e., minimal down time), a single CP system implements a firmware change by loading new firmware onto the system, saving state information pertaining to the old firmware, preventing the old firmware from communicating with the switches, bringing the new firmware to an active state and applying the saved state information to the new firmware.

Claims

1. A method of changing from first firmware to second firmware in a single processor system in which said processor communicates with a plurality of electronic devices, comprising:

(a) saving state information pertaining to said first firmware;

(b) preventing the processor from communicating with the electronic devices;

(c) ceasing execution of the first firmware;

(d) bringing the second firmware to an active state; and

(e) applying the saved state information to the second firmware.

2. The method of claim 1 further including prior to (d) loading the second firmware into memory accessible by said processor.

3. The method of claim 1 further including rebooting the processor between (c) and (d).

4. The method of claim 1 wherein (a) includes saving the state information to non-volatile memory.

5. The method of claim 1 wherein following (e) permitting the processor to communicate with the electronic devices using the second firmware.

6. The method of claim 1 wherein the electronic devices comprise network switches.

7. A method of changing from first firmware to second firmware in a single processor system in which said processor communicates with a plurality of electronic devices, comprising:

(a) saving state information pertaining to said first firmware;

(b) preventing the processor from communicating with the electronic devices;

(c) ceasing execution of the first firmware;

(d) bringing the second firmware to an active state; and

(e) synchronizing the second firmware to the first firmware using the saved state information.

8. A method of changing from first firmware to second firmware in a single processor system in which said processor communicates with a plurality of electronic devices, comprising:

(a) loading the second firmware onto the system in which the first firmware is actively running;

(b) saving state information pertaining to said first firmware;

(c) preventing the processor from communicating with the electronic devices;

(d) ceasing execution of the first firmware;

(e) bringing the second firmware to an active state; and

(f) synchronizing the second firmware to the first firmware using the saved state information.

9. A system, comprising:

a plurality of electronic devices; and

a control processor that executes firmware and communicates with the electronic devices,

said control processor having memory;

wherein the firmware being executed by said control processor can be changed to new firmware, the change over to the new firmware occurring by saving state information pertaining to the currently executing firmware in said memory, preventing the processor from communicating with the electronic devices, ceasing execution of the currently executing firmware, bringing the new firmware to an active state, and applying the saved state information to the new firmware.

10. The system of claim 9 wherein the firmware change over also includes loading the new firmware into said memory.

11. The system of claim 9 wherein the firmware change over also includes rebooting the control processor.

12. The system of claim 9 wherein said memory comprises non-volatile memory.

13. The system of claim 9 wherein the firmware change over also includes the control processor again communicating with the electronic devices using the new firmware.

14. The system of claim 9 wherein the electronic devices comprise network switches.

15. A control processor coupled to electronic devices, comprising:

a CPU; and

memory coupled to said CPU and containing CPU executable firmware having associated state information;

wherein the firmware being executed by said CPU can be changed to new firmware, the change over to the new firmware occurring by saving state information pertaining to the currently executing firmware in said memory, preventing the control processor from communicating with the electronic devices, ceasing execution of the currently executing firmware, bringing the new firmware to an active state, and applying the saved state information to the new firmware.

16. The control processor of claim 15 wherein the firmware change over also includes loading the new firmware said memory.

17. The control processor of claim 15 wherein the firmware change over also includes rebooting the control processor.

18. The control processor of claim 15 wherein said memory comprises non-volatile memory.

19. The control processor of claim 15 wherein the firmware change over also includes the control processor again communicating with the electronic devices using the new firmware.

20. The control processor of claim 15 wherein the electronic devices comprise network switches.

21. A computer readable storage medium for storing an executable set of software instructions that are executable by a CPU, said software instructions being operable to change firmware in a processor from first firmware to second firmware, said processor adapted to communicate with a plurality of electronic devices, said software instructions comprising:

(a) a means for saving state information pertaining to said first firmware;

(b) a means for preventing the processor from communicating with the electronic devices;

(c) a means for ceasing execution of the first firmware;

(d) a means for bringing the second firmware to an active state; and

(e) a means for applying the saved state information to the second firmware.

22. The storage medium of claim 21 further including a means for loading the second firmware into memory accessible by said processor prior to the means in (d) bringing the second firmware to an active state.

23. The storage medium of claim 21 further including a means for rebooting the processor between the means in (c) ceasing execution and the means in (d) bring the second firmware to the active state.

24. The storage medium of claim 21 wherein the means in (a) includes a means for saving the state information to non-volatile memory.

25. The storage medium of claim 21 further including a means for permitting the processor to communicate with the electronic devices using the second firmware following the means in (e) applying the saved state information to the second firmware.

26. The storage medium of claim 21 wherein the electronic devices comprise network switches.

27. A method of changing from first firmware to second firmware in a single processor system in which said processor communicates with a plurality of electronic devices, comprising:

(a) launching a utility as a standby image;

(b) synchronizing the standby image to an active image in which the first firmware is running;

(c) preventing the processor from communicating with the electronic devices;

(d) making the second firmware a standby image;

(e) launching the utility as an active image;

(f) synchronizing the standby image to the active image; and

(g) failing over from the active image to the standby image.

28. The method of claim 27 wherein (b) includes saving state information pertaining to the active image to non-volatile memory.

29. The method of claim 27 wherein (f) includes retrieving state information from the non-volatile memory and applying the retrieved state information to the standby image.

30. The method of claim 27 wherein (a) includes enabling loopback to cause state information update messages destined for another processor system to be rerouted and provided to the standby image.

31. The method of claim 27 wherein (e) includes enabling loopback to cause state information update messages destined for another processor system to be rerouted and provided to the standby image.

32. The method of claim 27 further including prior to (d) loading the second firmware into memory accessible by said processor.

33. A system, comprising:

a plurality of electronic devices; and

a control processor that executes firmware and a utility and communicates with the electronic devices, said control processor having memory;

wherein the firmware being executed by said control processor can be changed to new firmware, the change over to the new firmware occurring by launching the utility as a standby image, synchronizing the standby image to an active image in which the currently executing firmware is running, preventing the control processor from communicating with the electronic devices, making the new firmware a standby image, launching the utility as an active image, synchronizing the standby image to the active image, and failing over from the active image to the standby image.

34. The system of claim 33 wherein synchronizing the standby image containing the utility to the active image containing the currently executing firmware to be replaced includes saving state information pertaining to the active image to non-volatile memory.

35. The system of claim 33 wherein synchronizing the standby image containing the new firmware to the active image containing the utility includes retrieving state information from the non-volatile memory and applying the retrieved state information to the standby image.

36. The system of claim 33 wherein launching the utility as a standby image includes enabling loopback to cause state information update messages destined for another processor system to be rerouted and provided to the standby image.

37. The system of claim 33 wherein launching the utility as an active image includes enabling loopback to cause state information update messages destined for another processor system to be rerouted and provided to the standby image.

38. The system of claim 33 wherein the firmware change over also includes loading the new firmware into said memory.

39. A control processor coupled to electronic devices, comprising:

a CPU; and

memory coupled to said CPU and containing CPU executable firmware having associated state information and a utility;

wherein the firmware being executed by said control processor can be changed to new firmware, the change over to the new firmware occurring by launching the utility as a standby image, synchronizing the standby image to an active image in which the currently executing firmware is running, preventing the control processor from communicating with the electronic devices, making the new firmware a standby image, launching the utility as an active image, synchronizing the standby image to the active image, and failing over from the active image to the standby image.

40. The control processor of claim 39 wherein synchronizing the standby image containing the utility to the active image containing the currently executing firmware to be replaced includes saving state information pertaining to the active image to non-volatile memory.

41. The control processor of claim 39 wherein synchronizing the standby image containing the new firmware to the active image containing the utility includes retrieving state information from the non-volatile memory and applying the retrieved state information to the standby image.

42. The control processor of claim 39 wherein launching the utility as a standby image includes enabling loopback to cause state information update messages destined for another processor system to be rerouted and provided to the standby image.

43. The control processor of claim 39 wherein launching the utility as an active image includes enabling loopback to cause state information update messages destined for another processor system to be rerouted and provided to the standby image.