System and method for loading compressed embedded diagnostics

• US 5,530,847 A
• Filed: 07/14/1993
• Issued: 06/25/1996
• Est. Priority Date: 03/22/1993
• Status: Expired due to Term

• Current Assignee: Dell USA LP (Dell Technologies Inc.)
• Original Assignee: Dell USA LP (Dell Technologies Inc.)
• Inventors: Schieve, Eric, Finch, Richard
• Primary Examiner(s): Canney, Vincent P.
• Application Number:
  US08/091,548
• Time in Patent Office: 1,077 Days
• Field of Search: 395/575, 3/700, 371/18, 371/21.1, 364/265.5, 364/267, 364/267.5, 364/267.6, 364/267.7
• US Class Current: 714/38.13
• CPC Class Codes: G06F 11/0757 by exceeding a time limit, i.e. time-out, e.g. watchdogs
• CPC Class Codes: G06F 11/22 Detection or location of defective computer hardware by testing during standby operation or during idle time, e.g. start-up testing
• CPC Class Codes: G06F 9/4401 Bootstrapping security arrangements therefor G06F21/57

Abstract

Disclosed are a system and method for loading diagnostic routines for execution in a computer system. The method comprises the steps of (1) executing a boot loading routine stored in non-volatile memory within the computer system, the boot loading routine providing an environment in lieu of an operating system of the computer system within which to execute diagnostic routines, the boot loading routine including a decompression routine, (2) decompressing a compressed diagnostic routine stored in the non-volatile memory into video random access memory (RAM) and (3) executing the decompressed diagnostic routine under control of the boot loading routine. The present invention, in its preferred embodiment, allows relatively large diagnostic routines to be stored in electrically erasable programmable read only memory ("EEPROM") and decompressed, as required, into video RAM for execution, without requiring the computer'"'"'s operating system to function.

Claims

1. A method of loading diagnostic routines in a computer system, comprising the steps of:

executing a boot loading routine stored in non-volatile memory within said computer system, said boot loading routine including a decompression routine;

decompressing a driver routine and a compressed diagnostic routine stored in said non volatile memory into video random access memory (RAM), said driver routine providing an environment in lieu of an operating system of said computer system within which to execute said diagnostic routine; and

executing said driver routine under control of said boot loading routine.

2. The method as recited in claim 1 further comprising the step of verifying an integrity of information in said compressed diagnostic routine with said boot loading routine prior to performing said step of decompressing.

3. The method as recited in claim 1 further comprising the step of testing a functioning of a video subsystem of said computer system to determine whether said video subsystem is capable of operating in conjunction with said diagnostic routine prior to performing said step of decompressing.

4. The method as recited in claim 1 further comprising the step of determining a presence of a video monitor of said computer system prior to performing said step of decompressing.

5. The method as recited in claim 1 further comprising the step of decompressing a subsequent diagnostic routine following execution of said decompressed diagnostic routine.

6. The method as recited in claim 1 wherein said computer system is a personal computer (PC).

7. The method as recited in claim 1 wherein said non volatile memory is electrically programmable read only memory (EEPROM).

8. A system for providing diagnostic routines for use in a computer, comprising:

a boot loading routine stored in non volatile memory within said computer and including a decompression routine; and

a driver routine and a compressed diagnostic routine stored in said non volatile memory, said driver routine providing an environment in lieu of an operating system of said computer within which to execute said diagnostic routine, said decompression routine decompressing said diagnostic routine into video random access memory (RAM), said boot loading routine initiating execution of said driver routine.

9. The system as recited in claim 8 further comprising a microprocessor for executing said boot loading routine and said decompressed diagnostic routine.

10. The system as recited in claim 8 wherein said computer comprises a video subsystem having a monitor and said video RAM, said video subsystem allowing said computer to communicate with a user.

11. The system as recited in claim 8 wherein said non volatile memory contains a plurality of compressed diagnostic routines.

12. The system as recited in claim 8 wherein said boot loading routine includes a routine for verifying an integrity of information in said compressed diagnostic routine.

13. The system as recited in claim 8 wherein said boot loading routine includes a routine for testing a functioning of a video subsystem of said computer to determine whether said video subsystem is capable of communicating with a user.

14. The system as recited in claim 8 wherein said boot loading routine decompresses a subsequent selected diagnostic routine following execution of said decompressed diagnostic routine.

15. The system as recited in claim 8 wherein said computer is a personal computer (PC).

16. The system as recited in claim 8 wherein said non volatile memory is electrically erasable programmable read only memory (EEPROM).

17. In a personal computer (PC) having a microprocessor, video random access memory (RAM), electrically erasable programmable read only memory (EEPROM) and a bus coupling said microprocessor to said video RAM and said EEPROM, a method of performing diagnostic routines, comprising the steps of:

executing, with said microprocessor, a boot loading routine stored in said EEPROM, said boot loading routine containing a decompression routine; and

decompressing, with said decompression routine, a driver routine and an initial portion of diagnostic routine code stored in said EEPROM in compressed form, said driver routine providing an elemental operating system to support performance of said initial portion, said initial portion loaded into said video RAM for execution by said microprocessor, said driver routine decompressing and loading a subsequent portion of diagnostic routine code into said video RAM following execution of said initial portion.

18. The personal computer as recited in claim 17 further comprising the step of verifying an integrity of information in said diagnostic routine code with said boot loading routine prior to performing said step of decompressing.

19. The personal computer as recited in claim 17 further comprising the step of testing a functioning of a video subsystem of said PC to determine whether said video subsystem is capable of operating in conjunction with said diagnostic routine code prior to performing said step of decompressing.

20. The personal computer as recited in claim 17 further comprising the step of determining a presence of a video monitor of said PC prior to performing said step of decompressing.

21. A computer memory subsystem in a computer system, comprising:

flash read only memory (ROM) containing (1) a boot loading routine, said boot loading routine including a decompression routine, (2) a driver routine, said driver routine providing an environment in lieu of an operating system of said computer system within which to execute diagnostic routines and (3) a compressed diagnostic routine; and

video random access memory (RAM) for storing said driver routine and a decompressed diagnostic routine, said decompression routine decompressing said compressed diagnostic routine to produce said decompressed diagnostic routine, said boot loading routine storing said decompressed diagnostic routine in said video RAM and causing execution of said driver routine.

22. The subsystem as recited in claim 21 wherein said computer system comprises a microprocessor for executing said boot loading routine and said decompressed diagnostic routine.

23. The subsystem as recited in claim 21 wherein said computer system comprises a video subsystem having a monitor and said video RAM, said video subsystem allowing said computer to communicate with a user.

24. The subsystem as recited in claim 21 wherein said flash ROM contains a plurality of compressed diagnostic routines.

25. The subsystem as recited in claim 21 wherein said boot loading routine includes a routine for verifying an integrity of information in said compressed diagnostic routine.

26. The subsystem as recited in claim 21 wherein said boot loading routine includes a routine for testing a functioning of a video subsystem of said computer system to determine whether said video subsystem is capable of communicating with a user.

27. The subsystem as recited in claim 21 wherein said boot loading routine decompresses a subsequent selected diagnostic routine following execution of said decompressed diagnostic routine.

28. The subsystem as recited in claim 21 wherein said computer system is a personal computer (PC).

29. A method of loading diagnostic programs in a personal computer (PC), comprising the steps of:

verifying an integrity of information in compressed diagnostic routines stored in non volatile memory with a boot loading routine;

testing a functioning of a video subsystem of said PC to determine whether said video subsystem is capable of operating in conjunction with said diagnostic programs;

determining a presence of a video monitor of said PC;

decompressing a driver routine and a selected one of said compressed diagnostic routines to thereby transform said selected one into a decompressed diagnostic routine;

storing said decompressed diagnostic routine in video random access memory (RAM) within said video subsystem;

executing said driver routine; and

decompressing a subsequent selected diagnostic routine following execution of said decompressed diagnostic routine, said boot loading routine performing said testing, determining, decompressing and storing steps, said driver routine performing said executing step.

30. The method as recited in claim 29 wherein said non volatile memory is electrically erasable programmable read only memory (EEPROM).

31. The method as recited in claim 29 wherein said PC further comprises a keyboard allowing a user to interact with said diagnostic routine.

32. The method as recited in claim 29 wherein said method of loading diagnostic programs is initiated by pressing a reset button on said PC twice within a predetermined period of time.

33. A personal computer (PC), comprising:

a microprocessor;

a video subsystem having a monitor and video random access memory (RAM), said video subsystem allowing said PC to communicate with a user;

non volatile memory, said non volatile memory containing a boot loading routine, a driver routine and a plurality of selectable compressed diagnostic routines, said boot loading routine containing;

a routine for verifying an integrity of information in said plurality of compressed diagnostic routines;

a routine for testing a functioning of said video subsystem to determine whether said video subsystem is capable of communicating with said user;

a routine for decompressing a selected one of said compressed diagnostic routines to thereby transform said selected one into a decompressed diagnostic routine;

a routine for storing said decompressed diagnostic routine in said video RAM within said video subsystem; and

a driver routine for providing an elemental operating system to support performance of diagnostics on said PC and for executing said decompressed diagnostic routine, said decompressing routine decompressing a subsequent selected diagnostic routine following execution of said decompressed diagnostic routine.

34. The PC as recited in claim 33 wherein said non volatile memory is electrically erasable programmable read only memory (EEPROM).

35. The PC as recited in claim 33 wherein said PC further comprises a keyboard allowing a user to interact with said decompressed diagnostic routine.

36. The PC as recited in claim 33 wherein said boot loading routine is invoked by pressing a reset button on said PC twice within a predetermined period of time.