United States Patent [19}
`Bizzarri
`
`US0057322
`68A
`[11] Patent Number:
`[45] Date of Patent:
`
`5,732,268
`Mar. 24, 1998
`
`[54] EXTENDED BIOS ADAPTED TO ESTABLISH
`REMOTE COMMUNICATION FOR
`DIAGNOSTICS AND REPAIR
`
`['75] Inventor: Maurice W. Bizzarri. Palo Alto. Calif.
`
`[73] Assignee: Award Software International. Mt.
`View. Calif.
`
`[21] Appl. No.: 608,028
`[22] Filed:
`Feb. 26, 1996
`
`6
`[51] Int. Cl. .................................................... .. G06F 11/34
`[52] US. Cl. ........................... .. 395/652; 395/712
`[58] Field of Search ................................... .. 395/652. 712,
`39$”04
`
`[56]
`
`References Cited
`\
`U.S_ PATENT DOCUMENTS
`
`5,280,627
`5,452,454
`5,596,711
`
`l/1994 Flaherty et a].
`9/1995 Basu ............. ..
`111997 Burckhartt et a1.
`
`395/652
`395/652
`395118221
`
`Primary Examiner-Emanuel T. Voeltz
`Assistant Emminer—.lohn Q. Chavis
`Attorney, Agent, or Firm-—Donald R. Boys
`{57]
`ABSTRACT
`
`An extended basic input output system (E-BIOS) has a ?rst
`portion of code for providing power-on self-test (POST) and
`boot functions for a ?rst computer. including code for
`sensing if the ?rst computer does not boot. In the event of
`failure to boot. a second portion of code in the E-BIOS
`directs establishing communication link with a remote diag
`nostics and repair computer. When communication is
`established. a master code kernel at the diagnostics and
`repair computer may be cxccutcd to download a Skwe kernel
`to random access memory of the ?rst computer. blowing an
`automatic Software kernel or an operator at the diagnostics
`and repair computer to access and modify code and data in
`memory devices of the ?rst computer, and to reboot the ?rst
`computer after repair. Communication links may be by
`telephone modern. either analog or integrated Services Digi
`tal Network (ISDN). or by network links. In one embodi
`ment cooperation between the slave kernel and the master
`kernel is such that an operator may operate the diagnostics
`and repair computer as though it were the ?rst computer.
`
`20 Claims, 3 Drawing Sheets
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`/ 21
`Power On
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`f 23
`Load BIOS
`Begin to Execute
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`27\
`
`Boot
`Normally
`
`Boot
`Problem
`Encountered
`'2?
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`29 \ Yes (Failure to Boot)
`
`15
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`Modem
`
`Net
`
`Establish Communication
`With Remote Diagnostic
`and Repair Facility
`
`1
`
`EX 1020
`IPR of Pat. No. 6,892,304
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`

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`U.S. Patent
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`Mar. 24, 1993
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`Sheet 1 of 3
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`5,732,268
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`US. Patent
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`Mar. 24, 1998
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`Sheet 2 of 3
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`5,732,268
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`[21
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`Power 0n
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`/ 23
`
`Load BIOS
`Begin to Execute
`
`27\
`
`Boot
`Normally
`
`29 \ Yes (Failure to Boot)
`
`15
`
`‘in-21in- Establish Communication
`with Remote Diagnostic
`I Net
`and Repair Facility
`
`Fig. 2
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`3
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`

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`US. Patent
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`Mar. 24, 1998
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`Sheet 3 of 3
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`5,732,268
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`K31
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`Connect
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`»‘ f 33
`Downtoad Slave
`Kernel
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`37 \
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`Counter
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`Execute
`Slave
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`Fig. 3
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`4
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`5,732,268
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`1
`EXTENDED BIOS ADAPTED TO ESTABLISH
`REMOTE COMMUNICATION FOR
`DIAGNOSTICS AND REPAIR
`
`FIELD OF THE INVENTION
`The present invention is in the area of apparatus and
`methods for diagnosing and repairing failed computer
`systems, and pertains more particularly to computer code for
`basic input output systems (BIOS) devoted to diagnosis and
`repair.
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`?oppy drive, place another in its place. and try again. Once
`a usable DOS was loaded, one could present different disks
`to the ?oppy drive(s) for access to applications and data
`?les.
`Things in a sense are not a lot di?’erent now. The principle
`dilferences are that mass storage devices have evolved and
`operating systems and applications are much larger and
`more complicated.
`The motivation for evolution is functionality. As devel
`opers have envisioned ever more elaborate and intricate
`computer-related goodies such as high-resolution, color
`displays, CD-rom drives, high-density hard disk drives.
`menu-driven user interfaces, windows-type interfaces,
`modem communications, the Internet and the World-Wide
`Web, and much more, it has been necessary to develop faster
`and more powerful CPUs, Higher density and faster mass
`storage. and ever-larger operating systems.
`Because of the large size of operating systems today, such
`as WindowsTM and UNIXTM systems for example, it is
`completely impractical to store the operating system on a
`?oppy disk or in ROM, although some minimum versions of
`some operating systems are available in ROM for special
`ized purposes. Operating systems are therefore stored in
`non-volatile mass‘ storage. typically on a hard disk. In such
`a system. at power on or reset. the BIOS ROM is accessed
`?rst, loaded into RAM. and executed. After POST, a BIOS
`code causes the system to access a local hard disk at an
`address. typically called the boot sector, where code is stored
`for directing loading of the operating system from the hard
`disk and ?nalizing preparation of the system for continuing
`operation. The operating system, which may be several
`megabytes of code. is then loaded. and the system is directed
`to a starting point for operator instructions. which may be
`with an application loaded and ready to run. or at a point
`where an operator may select an application.
`For those familiar with DOS operation the point that the
`user is able to select and manipulate operation is the familiar
`DOS prompt. For those familiar with Microsoft WindowsTM
`this point is the familiar interactive interface showing
`ICONS for program groups. For Apple MacintoshTM users
`this point is the familiar Desktop graphics interface.
`As long as all hardware and software systems are
`operable. such an initiation sequence is routine. A hard disk
`drive, however, is a mechanical device, and thus vulnerable
`to a much broader variety of potential di?iculties than an IC
`ROM. Because of this mechanical vulnerability, it often
`happens that a system cannot boot because the boot disk
`becomes inoperable. There are many other hardware failures
`that might occur other than the failure of a hard disk that
`would prevent a PC from booting and operating as intended
`As well as hardware-only failures, there are many situa
`tions that can occur to render software corrupted. which
`condition may leave a PC unable to boot. such as corruption
`of the boot sector of the hard disk boot drive, or corruption
`of a File Allocation Table (FAT).
`Early PCs were self-su?icient, stand-alone systems, com
`prising all of the hardware and software necessary to per
`form intended functions. PCs at the time of the present
`invention, however. are typically provided with some form
`of communication link to other computers. Most PCs at a
`minimum have a telephone modem connection, and may
`communicate with another computer over a telephone line in
`either an analog or a digital protocol.
`PCs used in a business setting are often connected
`together in a local area network (LAN), whereby individual
`workstations may have relatively fewer hardware compo
`
`BACKGROUND OF THE INVENTION
`Because a computer. without operating instructions
`loaded, is essentially a piece of dumb hardware, there must
`be some relatively standard set of beginning instructions for
`the computer to follow. readily accessible and loadable into
`the computer’s operating memory to direct the process of
`testing the computer’s hardware and connectivity, and then
`loading all of the various operating code that is necessary for
`the computer to perform useful tasks. Typically this begin
`ning code is called a basic input output system (BIOS),
`which includes a power-on self-test (POST) procedure, to
`assure that all circuits are active. properly connected. and
`functional before attempting to load and initiate all of the
`code needed to operate.
`The BIOS in most instances is a relatively short code set
`embedded in a non-volatile, read-only memory (ROM). such
`as an electrically-erasable programmable read-only memory
`(EEPROM). accessible to the central processing unit (CPU)
`of a computer at the instant of power on. Partly because code
`can be accessed and executed from random access memory
`(RAM) more quickly than from read-only memory (ROM),
`the BIOS code is typically loaded immediately into RAM
`from ROM at power on, and executed from RAM.
`35
`Although BIOS is fundamental to testing a computer’s
`operating equipment and basic BIOS functions continue to
`be used during subsequent operation. BIOS is not a su?icient
`system for continuing successful system operations. There
`are many functions, among them reading and writing data to
`mass storage systems such a ?oppy disk drives (FDD), hard
`disk drives (HDD) and CD-ROM drives, which have to be
`loaded as well after executing the initial BIOS to render a
`computer fully operable. All of the code to make the
`computer capable of performing such basic functions is
`referred to in the art as the Operating System (OS).
`In very early personal computers, before widespread use
`of hard disk drives (HDD), an operating system such as the
`IBM-compatible Disk Operating System (DOS) would typi
`cally be recorded on a ?oppy disk along with an application
`50
`such as a word processor or a spread-sheet program. A
`?oppy disk with DOS and a boot sector was called a Boot
`disk, and the name is still used, although operating systems
`and boot sectors are typically now recorded on hard disk
`drives. One would place a boot disk in a ?oppy drive in the
`computer. then turn the thing on. The BIOS would load from
`a resident ROM, perform a simple POST routine, then poll
`the ?oppy (hives (often there was only one) to ?nd DOS.
`When Dos was located, the BIOS would cause it to be
`loaded, and then present the DOS prompt for instruction
`from the user. BIOS code and DOS would remain in RAM
`for access by the CPU as needed for basic and routine
`functions. The user could then boot the word processor or
`other application on the ?oppy and go to work.
`In this early and simple scenario, if DOS code on a boot
`disk were to become corrupted, the computer would not
`boot, and one could simply remove the boot disk from the
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`3
`nents and devices and much less locally-stored software. and
`hardware and software resources are shared on the LAN.
`In any setting. stand-alone. modem connected. or LAN
`connected. the conventional procedure in many cases for
`dealing with a computer that won’t boot is for a maintenance
`person to visit the failing PC with hardware and software
`tools. The maintenance person can boot the o?ending PC
`typically via one of the ?oppy drives. using a ?oppy boot
`disk with an operating system such as DOS that is small
`enough to store on the ?oppy. load diagnostic routines.
`determine the fault or faults. and perform the needed repairs.
`This system-manager approach to maintenance is a time
`consuming and person-oriented approach. and is therefore
`expensive and time-consuming.
`There is a conventional diagnostic system called Simple
`Network Management Protocol (SNMP). well-known in the
`art. that allows a service person at a remote site to commu
`nicate with a troubled PC and to perform some alterations.
`but SNMP requires that at least a minimum operating system
`be active and operable in the troubled PC. For those cases in
`which a PC will not boot. SNMP has no value.
`What is needed for those PCs having some mode of
`communication with other devices. either via modem or on
`a LAN. is an apparatus and method whereby. in the event of
`failure and an inability to boot. a remote diagnostic center
`may be contacted automatically. and a remote boot. called an
`extended boot by the inventor. may be performed. through
`which the failed machine may be remotely diagnosed and
`placed back in operating condition. saving the expense and
`time of sending a repair person to the failed machine.
`In embodiments of the present invention such a needed
`system is initiated by code in a unique local BIOS, called
`E-BIOS. for Extended BIOS. by the inventor. In the event of
`failure to-boot properly. the E-BIOS establishes a commu
`nication link with a designated remote diagnostics and repair
`console.
`In one embodiment code to boot the failed machine is
`downloaded from the remote center to the failed local PC by
`an operator at the remote facility, and diagnostics for the
`failed system may be managed at the remote facility.
`
`4
`the CPU to perform startup functions for a computer, includ
`ing initiating boot operations, and a second code portion
`recorded in the ROM device and adapted for execution by
`the CPU to establish communication with a remote com
`puter. Code execution by the CPU is directed from the ?rst
`code por1ion to the second code portion upon failure to
`complete said boot operations.
`In computers according to various embodiments of the
`invention. connection may be by telephone modern. analog
`or digital. or by network link. depending on availability.
`Automatic connection of a failing computer to a remote
`diagnostics and repair computer through a communication
`link provides a system for modifying code and data in a ?rst
`computer having a ?rst CPU upon failure of the ?rst
`computer to boot. comprising a second computer having a
`second CPU. the second computer connected to the ?rst
`computer by a communication link; a master code kernel
`and a slave code kernel stored on a memory device at the
`second computer; and an extended basic input output system
`(Ii-BIOS) in the ?rst computer. Upon sensing failure of the
`?rst computer to boot. the E-BIOS establishes communica
`tion with the second computer over the communication link.
`and the second CPU in response causes a copy of the slave
`kernel to be copied to the RAM of the ?rst computer and to
`be made available to the ?rst CPU for execution. and
`wherein. with a copy of the slave kernel in the ?rst computer
`and the master kernel active in the second computer. a user
`at the second computer may diagnose and modify code and
`data in the ?rst computer from the second computer.
`An operator or automatic software at the second computer
`in this aspect may repair a corrupted boot sector on a disk
`drive of the ?rst computer. or modify code of ?le allocation
`tables at the ?rst computer.
`In another aspect a method of diagnosing and modifying
`code and data in read/write memory devices and mass
`storage devices of a ?rst computer is provided. comprising
`steps of (a) establishing communication with the ?rst com
`puter over a communication link from a diagnostic and
`repair computer; (b) loading and executing a master kernel
`at the diagnostic and repair computer; (0) downloading a
`slave operating system kernel to the ?rst computer from the
`second computer; and (d) accessing and modifying code and
`data on read/write memory devices and mass storage devices
`in the ?rst computer through activity at the second computer.
`The ?rst computer may be caused to attempt to reboot after
`step (d). A method for establishing contact with a remote
`repair center computer upon failure of a local computer to
`boot is provided in yet another aspect. comprising steps of:
`(a) sensing failure of the local computer to boot through
`action of a ?rst portion of code in an extended basic input
`output system (E-BIOS) installed and operable in the ?rst
`computer; and (b) activating a communication link to the
`remote repair center computer through action of a second
`portion of code in the E-BIOS. the second potion of code
`executed in response to the failure of the ?rst computer to
`boot.
`The embodiments of the present invention and methods of
`practicing the invention provide a unique system and pro
`tocol for accessing. diagnosing and repairing computers that
`fail to boot, without the expensive and time-consuming step
`of sending a technician or engineer to the failed computer to
`reboot the computer from a ?oppy. and to then diagnose and
`modify corrupted code and data.
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`SUMlVlARY OF THE INVENTION
`In an embodiment of the invention a basic input output
`system (BIOS) is provided comprising a non-volatile
`memory; a ?rst code portion recorded in the non-volatile
`memory and adapted for execution by a CPU to perform
`startup functions for a computer. including initiating boot
`operations; and a second code portion recorded in the
`non-volatile memory and adapted for execution by the CPU
`50
`to establish communication with a remote computer. Code
`execution by the CPU is directed from the ?rst portion to the
`second portion upon failure to complete the boot operations.
`Communication with the remote computer may be estab
`lished over a telephone link by operating a telephone modem
`to dial a telephone number. using either an analog or digital
`line, and in some embodiments plln'al numbers may be
`dialed in a priority sequence until a connection is estab
`lished. Communication may be established as well over any
`network connection to remote computers.
`In an alternative embodiment a computer is provided
`comprising a CPU; a mass storage device coupled to the
`CPU and having a boot code sector and operating system
`code recorded thereon; a read-only memory ROM device
`coupled to the CPU; and a basic input output system (BIOS)
`coupled to the CPU. the BIOS having a ?rst code portion
`recorded in the ROM device and adapted for execution by
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`, BRIEF DESCRIPTION OF THE DRAWINGS
`FIG. 1 is a block diagram of an E-BIOS PC. an E-BIOS
`diagnostic center. and interconnection according to an
`embodiment of the present invention.
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`FIG. 2 is a logic ?ow diagram of operation of an EBIOS
`PC at boot up.
`FIG. 3 is a logic ?ow diagram of operation of diagnosis
`and repair after an E-BIOS PC and an E-BIOS diagnostic
`center are connected.
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`a pqiod of the computer being o?’. an intentional reboot
`occasioned by a keystroke combination or other signal. or a
`reboot as a result of the Power Good line going low may
`reason for a time su?icient to cause a reboot.
`At step 23 the E-BIOS is loaded into RAM and execution
`of the E-BIOS begins. At step 25 E-BIOS execution
`continues. performing POST and other BIOS startup
`functions. and. by virtue of being an E-BIOS. monitoring for
`any fault that will prevent completion of the boot process. As
`long as no fault is found that will prevent normal system
`operation. the boot process continues. including accessing
`the boot sector of a boot drive hard disk and loading code
`constituting an operating system from the boot drive.
`If. in the duration of the boot process. no fault is encoun
`tered which would prevent normal system operation. boot
`proceeds at step 27 to presenting on a display monitor the
`interactive interface allowing a user to take over and direct
`continuing operation. This point is the DOS prompt. the
`Windows“! interface. the Mac desktop. and so forth.
`If. in the processes at step 27. a fault is encountered that
`would prevent normal operation. control is diverted to step
`29. and speci?c code in the E-BIOS queries for a modem or
`a LAN connection. and ?nding one or the other. establishes
`communication with a remote E-BIOS diagnostic and repair
`unit (element 13 in FIG. 1). There are a number of options
`for the connection code. For example. a specific phone
`number or numbers may be programmed into a device
`accessible by the E-BIOS. and the numbers may have
`priority. such that the E-BIOS may try the numbers in a
`priority order. This is useful for situations wherein mainte
`nance personnel may be olf-site. and there is no certainty as
`to availability. When a quali?ed person answers such a call.
`he or she returns a preprogrammed signal. In the case of a
`LAN connection, there may be a speci?c node on the LAN
`designated as the diagnostic and repair site. or there may be
`several. again with a priority list accessible to the E-BIOS of
`the PC that fails to boot.
`It will be apparent to those with skill in the art that there
`are a broad variety of options that may be used by the
`E-BIOS to establish contact with a designated diagnostic
`and repair center.
`Depending on the speci?c embodiment. a user or an
`automatic software kernel at a remote unit 13 is noti?ed of
`a machine in need of service in one or more of a variety of
`ways. In the case of a large commercial network. there may
`be a speci?c node designated as the diagnostic and repair
`center. and this node may be in service at all times with a
`technician in attendance and the E-BIOS host active. In this
`case. when a PC on the LAN goes down and can’t reboot.
`and the E-BIOS at the failed PC signals for remote service.
`an on-screen message can be used to alert the service
`technician. perhaps coupled with an audio signal. In situa
`tions where a service technician might be running another
`program at the time a request is logged. there can still be an
`on-screen message or icon to alert the technician to boot the
`host software and initiate diagnosis and repair for the
`o?ending PC.
`In some cases. for example wherein an E-BIOS PC needs
`service and the E~BIOS calls a remote designated location
`by modern, a message may be left for a technician to access
`on return. who may then call the failed modem which is
`maintained in an answer mode by the E-BIOS until the
`service technician returns the call. Contact is then estab
`lished and remote diagnosis and repair may proceed.
`In the specific situations described above. operation of
`diagnosis and repair is performed by a trained technician at
`
`DESCRIPTION OF THE PREFERRED
`EMBODIMENTS
`FIG. 1 is a block diagram of a local E-BIOS PC 11
`connected to a remote E-BIOS diagnostic and repair facility
`13 by a communication link 15. A means of communicating
`is necessary for practicing the invention. but link 15 can be
`any of several well-known types. such as a serial link. a
`telephone modem connection. or a wide-area or a local area
`network connection. PC 11 has a unique E-BIOS 17 rather
`than a conventional PC BIOS. and facility 13 is equipped
`with code for cooperating with E-BIOS PC 11 over connec
`tion 15. This E-BIOS code in FIG. 1 is designated E-BIOS
`Host 19. and comprises a master kernel 20 and a slave kernel
`22.
`There are. in different embodiments of the present
`invention. at least two different ways that a diagnostic and
`repair facility 13 may operate. In one option. after connec
`tion is established. a human operator directs all interaction
`with the PC needing repair or modi?cation to boot and
`operate properly. In another option. an automatic software
`(AS) kernel 24 is provided to deal with the problems of the
`failed PC. and no human intervention is necessary.
`There are a number of possible reasons why an E-BIOS
`PC might fail to boot. Perhaps chief among these. without
`regard to importance. are (l) a physical failure of the boot
`drive. (2) code corruption in the boot sector of the boot
`drive. (3) corruption of the ?le allocation table (FAT). (4)
`BIOS setup corrupted (usually in real-time clock. and often
`called CMOS). and (5) a virus infection affecting code
`and/or data in CMOS or on a hard disk. In case (1) the
`necessary correction cannot be made from the remote
`location. and it is necessary to send a technician to the failed
`computer to physically repair or change out the olfending
`drive. In the cases of (2). (3). (4). and (5) diagnosis and
`repair can be made by methods of the present invention.
`In considering the relative importance or desirability of an
`automatic software kernel or human-directed operation. one
`attractive alternative is to provide. for a number of PCs, a
`diagnostic center wherein some PCs are equipped with the
`AS interface and some are human-directed. Such a center
`would vary in number of PCs depending on the service base,
`and e?iciency in response and service is provided by having
`the AS PCs respond ?rst to incoming requests for service.
`The AS PCs in this case are programmed to look for and ?x
`problems associated with the ?ve common problems listed
`above. In the event an AS PC cannot modify a failed PC to
`reboot. control is passed to a facility with a human-operator.
`who can then look for more unusual and dil‘n'cult problems.
`In this sort of facility there would be more AS PCs than
`human-directed. with a ratio of perhaps 5:1. depending on
`experience.
`Regardless of the number of E-BIOS PCs and E-BIOS
`diagnostic and repair facilities involved. however. the basic
`operation involves an operator or automatic software at a
`diagnostic and repair facility cooperating with a failed PC to
`get the failed machine operable again without the necessity
`of sending a repair technician to the offending machine.
`FIG. 2 is a logic ?ow diagram of operation of an E-BIOS
`PC at boot up. executing E-BIOS code. At step 21 power on
`is initiated. This may be from turning on the computer after
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`the remote diagnostic and repair PC. In an alternative
`embodiment operation is by an automatic software kernel.
`FIG. 3 is a logic ?ow diagram of operations between a
`failed E-BIOS PC 11 and a remote diagnostics and repair PC
`13 (FIG. 1) in an embodiment of the invention after the
`E-BIOS host is active on the diagnostics and repair PC and
`communication has been established with the failed E-BIOS
`PC. At step 31 communication is established. At step 33
`slave kernel 22 is downloaded from diagnostic and repair PC
`13 over link 15 to failed PC 11. In human-operated embodi
`ments the downloading is initiated by the human operator. In
`automatic operation the downloading is directed by AS
`kernel 24 (FIG. 1).
`At step 35 an attempt is made to execute slave kernel 22
`in RAM space of failed PC 11. If the slave fails, control
`returns to step 33. and another download is initiated Under
`human control this reboot process for the slave kernel may
`be repeated any number of times at the discretion of the
`operator. Under AS control a counter 37 records the number
`of tries. and aborts at some preprograrnmed integer. such as
`three.
`When and if at step 35 the slave is determined to be
`operable, control proceeds to step 39, and the slave is
`manipulated to diagnose and repair the failed PC.
`Considering an embodiment of the invention under
`human control. after slave kernel 22 is downloaded and
`tested. an interface at the diagnostic PC is provided emu
`lating the keyboard. screen, and ?oppy drive of the failed
`computer. providing a local environment at the diagnostic
`PC just as if the technician has traveled to the failed PC
`(which may be miles away) and is interfacing with the failed
`unit directly. Under this circumstance the repair technician
`may load ?oppy disks and diagnose and repair the failed PC
`as though he or she were directly operating the failed PC.
`The technician may. for example, load a DOS boot disk, and
`boot the failed PC from the ?oppy drive of the remote
`diagnostic and repair PC. He or she may then run diagnostic
`and repair programs such as FDISK, CHKDISK. and
`SCANDISK. which are familiar to user’s of DOS and
`Windows“! programs. Similar diagnostic programs are
`available and may be used in other embodiments. Opera
`tions at the diagnostic and repair PC are transferred via the
`master kernel running on the diagnostic and repair PC via
`link 15 to the failed PC. and by virtue of the slave km'nel
`operating there. directed to the appropriate hardware devices
`and addresses at the failed PC. In this instance, when one
`uses the A: ?oppy drive at the remote unit. the linked system
`operates as though that is the A: drive at the linked. failed
`PC.
`In addition to diagnosing and repairing code and data on
`a hard disk. other functions may be performed from the
`diagnostic and repair PC after connection and establishing
`the slave kernel on the failed PC. Among these are remote
`operation of all interactive BIOS functions, retrieval and
`restoration of ?les on local media, running diagnostics (as
`described above), retrieval of system con?guration
`information. such as system registry, CMOS. desldop man
`agement ?les (DMI), and any other information typically
`available to the BIOS or operating system.
`It will be apparent to those with skill in the art that there
`are many alterations that may be made in embodiments of
`the present invention described herein without departing
`from the spirit and scope of the invention. There are, for
`example, many alternative ways that code might be gener
`ated to accomplish the functions of the invention. It is well
`known to those with the skill in the art that the same
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`functions can be performed by code written in many di?’er
`ent ways. A variety of diagnostic and repair functions may
`be incorporated into different embodiments of the invention.
`and a number of these have been described above. Other
`alternatives include a variety of communication links. a
`variety of mixes of designated repair facilities. a variety of
`user interfaces that may be presented by the master kernel at
`the remote diagnostic and repair PC. and other alternatives
`as well. The scope of the invention is limited only by the
`claims which follow.
`What is claimed is:
`1. A basic input output system (BIOS) comprising;
`a ?rst code portion adapted for execution by a CPU to
`perform power on self test (POST) routine and to
`initiate boot operations; and
`a second code portion adapted for execution by the CPU
`to establish communication with a remote computer;
`wherein code execution by the CPU is directed from the
`?rst portion to the second portion upon failure to
`complete said boot operations.
`2. ABIOS as in claim 1 wherein the second portion directs
`the CPU to establish communication with a remote com.
`puter through a telephone link by operating a telephone
`modem to dial a telephone number.
`3. ABIOS as in claim 2 wherein the second portion directs
`the CPU to access a priority record of telephone numbers.
`and to dial the telephone numbers in order of priority until
`a call is answered and a pre-programmed signal is returned.
`4. ABIOS as in claim 1 wherein the second portion directs
`the CPU to establish communication with a remote com
`puter through a network communication adapter.
`5. A BIOS as in claim 1 wherein the non-volatile memory
`is an integrated circuit read-only memory (ROM) including
`Flash memory.
`6. A computer comprising:
`a CPU;
`a mass storage device coupled to the CPU and having a
`boot code sector and operating system code recorded
`thereon; and
`a basic input output system (BIOS) coupled to the CPU,
`the BIOS having a ?rst code portion adapted for
`execution by the CPU to perform power on self test
`(POST) routine and to initiate boot operations, and a
`second code portion adapted for execution by the CPU
`to establish communication with a remote computer;
`wherein code execution by the CPU is directed from the
`first code portion to the second code portion upon
`failure to complete said boot operations.
`7. A computer as in claim 6 wherein the second code
`portion directs the CPU to establish communication with a
`remote computer through a telephone link by operating a
`telephone modem to dial a telephone number.
`8. A computer as in claim 7 wherein the second portion
`directs the CPU to access a priority record of telephone
`numbers, and to dial the telephone numbers in order of
`priority until a call is answered and a pre-programmed signal
`is returned.
`9. A computer as in claim 6 wherein the second portion
`directs the CPU to establish communication with a remote
`computer through a network communication adapter.
`10. A system for modifying code and data in a ?rst
`computer having a ?rst CPU upon failure of the ?rst
`computer to boot, comprising:
`a second computer having a second CPU. the second
`computer connected to the ?rst computer by a commu
`nication link;
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`a master code kernel and a slave code kernel stored on a
`memory device at the second computer; and
`an extended basic input output system (E-BIOS) in the
`?rst computer;
`wherein. upon sensing failure of the ?rst computer to
`boot. the E-BIOS establishes communication with the
`second computer over the communication link. and the
`second CPU in response causes a copy of the slave
`kernel to be copied to the RAM of the ?rst computer
`and to be made available to the ?rst CPU for execution,
`and wherein. with a copy of the slave kernel in the ?rst
`computer and the master kernel active in the second
`computer. a user at the second computer may diagnose