Method and system for preserving crash dump in a diskless system

• US 20060156057A1
• Filed: 01/13/2005
• Published: 07/13/2006
• Est. Priority Date: 01/13/2005
• Status: Active Grant

• Current Assignee: Nokia Solutions and Networks US LLC (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Babu, Venkatesh
• Granted Patent: US 7,484,127 B2
• Time in Patent Office: Days
• US Class Current: 714/5
• CPC Class Codes: G06F 11/0742 in a data processing system embedded in a mobile device, e.g. mobile phones, handheld devices
• CPC Class Codes: G06F 11/0778 Dumping, i.e. gathering error/state information after a fault for later diagnosis
• CPC Class Codes: G06F 11/1441 Resetting or repowering

Abstract

The invention discloses a method for preserving crash dump data in case of operating system crash in a diskless device. The method and the system according to the invention uses two stage booting where in a primary and a secondary kernel are loaded. The primary kernel is a compact kernel that comprises a limited set of functionality and the secondary kernel is a fully functional kernel used for running applications. In case of a crash of the secondary kernel, the kernel prepares a jump back to the primary kernel. Then the primary kernel preserves the crash dump support data and secondary kernel'"'"'s RAM contents by sending it to a remote system which can store it on a nonvolatile memory.

Claims

1. A method for preserving crash dump in a diskless system in a situation where operating system crashes, which method comprising:

loading and booting a primary operating system kernel;

preparing environment for booting a secondary operating system kernel by means of said primary kernel;

loading and booting a secondary operating system kernel;

wherein in case of crash;

preparing said secondary kernel for jumping back to said primary kernel; and

preserving crash dump data and jumping back to said primary kernel for storing the preserved data.

2. A method according to claim 1, wherein said primary kernel is a stripped version of said secondary kernel.

3. A method according to claim 1, wherein said jumping back to said primary kernel is performed through a boot loader.

4. A method according to claim 3, wherein said primary kernel is configured to determine if the secondary kernel has crashed.

5. A method according to claim 1, wherein said preparing for jumping back to said primary kernel further comprising:

changing processor from protected mode to unprotected mode;

setting up segmentation, page and interrupt tables; and

clearing internal caches and buffers.

6. A method according to claim 5, wherein said changing to unprotected mode comprises arranging program code in virtual memory and physical memory into exactly same address for allowing said changing.

7. A method according to claim 1, wherein storing crash dump support data into a non-volatile memory.

8. A method according to claim 1, wherein storing crash dump data by transferring said crash dump data to a remote system.

9. A computer program embodied on a computer readable medium, said computer program for preserving crash dump data in a diskless system in a situation where operating system crashes, wherein the computer program performs the following steps when executed in a data-processing device:

loading and booting a primary operating system kernel;

preparing environment for booting a secondary operating system kernel by means of said primary kernel;

loading and booting a secondary operating system kernel;

wherein in case of crash;

preparing said secondary kernel for jumping back to said primary kernel; and

jumping back to said primary kernel for preserving secondary kernel'"'"'s RAM contents and crash dump support data.

10. A computer program according to claim 9, wherein said primary kernel is a stripped version of said secondary kernel.

11. A computer program according to claim 9, wherein said jumping back to said primary kernel is performed through a boot loader.

12. A computer program according to claim 11, wherein said primary kernel is configured to determine if the secondary kernel has crashed.

13. A computer program according to claim 9, wherein said preparing for jumping back to said primary kernel further comprising:

changing processor from protected mode to unprotected mode;

setting up segmentation, page and interrupt tables; and

clearing internal caches and buffers.

14. A computer program according to claim 13, wherein said changing to unprotected mode comprises arranging program code in virtual memory and physical memory into exactly same address for allowing said changing.

15. A computer program according to claim 9, wherein storing crash dump support data into a non-volatile memory.

16. A computer program according to claim 9, wherein storing crash dump data by transferring said crash dump data to a remote system.

17. A device configured to preserve crash dump data in a diskless system in a situation where operating system crashes, wherein the device comprising at least:

a memory for storing data and program code;

a processor for executing said program code;

a primary kernel that is loaded into said memory; and

a secondary kernel for executing applications that is loaded into said memory, wherein in case of crash the device is configured to jump from said secondary kernel to said primary kernel.

18. A device according to claim 17, wherein said primary kernel is a stripped version of said secondary kernel.

19. A device according to claim 17, wherein said device further comprises a boot loader for jumping back to said primary kernel.

20. A device according to claim 19, wherein said primary kernel is configured to determine if the secondary kernel has crashed.

21. A device according to claim 17, wherein said processor comprises protected and unprotected modes.

22. A device according to claim 17, wherein said device further comprises a non-volatile memory for storing crash dump data.

23. A device according to claim 17, wherein said device further comprises a connection to a remote system for storing crash dump data by transferring said crash dump data to said remote system.

24. A system configured to preserve crash dump data in a situation where operating system crashes in a device, wherein the system comprising at least:

A first device;

A second device; and

A network connection between said devices, where in the first device comprising at least;

a memory for storing data and program code;

a processor for executing said program code;

a primary kernel that is loaded into said memory; and

a secondary kernel for executing applications that is loaded into said memory, wherein in case of crash the device is configured to jump from said secondary kernel to said primary kernel.

25. A system according to claim 24, wherein said primary kernel of the first device is a stripped version of said secondary kernel of the first device.

26. A system according to claim 24, wherein said first device further comprises a boot loader for jumping back to said primary kernel.

27. A device according to claim 26, wherein said primary kernel is configured to determine if the secondary kernel has crashed.

28. A system according to claim 24, wherein said processor of the first device comprises protected and unprotected modes.

29. A system according to claim 24, wherein said first device further comprises a non-volatile memory for storing crash dump data.

30. A system according to claim 24, wherein said first device further comprises a connection to a remote system for storing crash dump data by transferring said crash dump data to said remote system.

31. A system according to claim 30, wherein said second device is configured to receive the crash dump data sent by the first device.