United States Patent [19J
`Bizzarri
`
`i-
`
`1111111111111111111111111111111111111111111111111
`US005732268A
`1111 Patent Number:
`(451 Date of Patent:
`
`5,732,268
`Mar. 24, 1998
`
`[54] EXTENDED BIOS ADAPfED TO ESTABLISH
`REMOTE COMMUNICATION FOR
`DIAGNOSTICS AND REPAIR
`
`[75]
`
`Inventor: Maurice W. Bizzarri, Palo Alto, Calif.
`
`Primary EXaminer-Emanuel T. Voeltz
`Assistant Examiner-John Q. Chavis
`Attorney, Agent, or Firm-Donald R. Boys
`[57]
`ABSTRACT
`
`[73] Assignee: Award Software International. Mt
`View, Calif.
`
`[21] Appl. No.: ()08,028
`
`Feb. 2(), 1996
`
`[22] Filed:
`Int. Cl. 6
`•••••••••••••••••••••••••••••••••••••••••••••••••••••• GO()F 11134
`[51]
`[52] U.S. CI •............................................. 395/()52; 395fi12
`[58] Field of Search ..................................... 395/652. 712,
`395fi04
`
`(56]
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`5,280,627
`5,452,454
`5,596,711
`
`111994 Flaherty et al .........•...•••...•....• 3951652
`911995 Basu ......•.........••...•..•...•.•.......•• 3951652
`111997 Burckhartt et al ...•....•...•.... 395/182.21
`
`An extended basic input output system (E-BIOS) has a first
`portion of code for providing power-on seJf-test (POST) and
`boot functions for a first computer, including code for
`sensing if the first 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(cid:173)
`nostics and repair computer. When communication is
`established. a master code kernel at the diagnostics and
`repair computer may be executed to download a slave kernel
`to random access memory of the first 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 first computer, and to reboot the first
`computer after repair. Communication links may be by
`telephone modem, either analog or integrated Services Digi(cid:173)
`tal Network (ISDN), or by network links. In one embodi(cid:173)
`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 first computer.
`
`20 Claims, 3 Drawing Sheets
`
`Power On
`
`21
`
`23
`
`Load BIOS
`Begin to Execute
`
`27
`
`No
`
`Boot
`Normally
`
`29
`
`Yes (Failure to Boot)
`
`15
`
`Modem
`
`Net
`
`Establish Communication
`With Remote Diagnostic
`and Repair Facility
`
`Patent Owner, Bot M8 LLC - Ex. 2001, p. 1
`
`

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`Fig. 1
`
`or Any Other Wide Area or Local Area Network
`
`LAN Link, Serial Link, Modem
`
`T
`
`15
`
`Optional AS Kernel
`
`Diagnostic Console
`
`PC Remote
`
`PC
`
`I
`
`20
`
`E-BIOS
`
`Kernel
`Slave
`
`I 1 MasteLJ
`
`Kernel
`
`17
`
`19
`
`13\
`
`11\
`
`Patent Owner, Bot M8 LLC - Ex. 2001, p. 2
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`

`

`U.S. Patent
`
`Mar. 24, 1998
`
`Sheet 2 of 3
`
`5,732,268
`
`Power On
`
`21
`
`23
`
`Load BIOS
`Begin to Execute
`
`27
`
`No
`
`Boot
`Normally
`
`29
`
`Yes (Failure to Boot)
`
`15
`
`Modem
`
`Net
`
`Establish Communication
`With Remote Diagnostic
`and Repair Facility
`
`Fig. 2
`
`Patent Owner, Bot M8 LLC - Ex. 2001, p. 3
`
`

`

`U.S. Patent
`
`Mar. 24, 1998
`
`Sheet 3 of 3
`
`5,732,268
`
`31
`
`Connect
`
`37
`
`Counter
`
`Download Slave
`Kernel
`
`Bad
`
`Good
`
`Execute
`Slave
`
`Fig. 3
`
`Patent Owner, Bot M8 LLC - Ex. 2001, p. 4
`
`

`

`1
`EXTENDED BIOS ADAPTED TO ESTABLISH
`REMOTE COMMUNICATION FOR
`DIAGNOSTICS AND REPAIR
`
`5,732,268
`
`s
`
`35
`
`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.
`
`2
`floppy drive, place another in its place, and try again. Once
`a usable DOS was loaded. one could present different disks
`to the floppy drive(s) for access to applications and data
`files.
`Things in a sense are not a lot different now. The principle
`differences 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-
`10 opers have envisioned ever more elaborate and intricate
`computer-related goodies such as high-resolution. color
`BACKGROUND OF THE INVENTION
`displays. CD-rom drives. high-density hard disk drives.
`menu-driven user interfaces. windows-type interfaces.
`Because a computer. without operating instructions
`loaded, is essentially a piece of dumb hardware, there must
`modem communications. the Internet and the World-Wide-
`be some relatively standard set of beginning instructions for 15 Web, and much more. it has been necessary to develop faster
`the computer to follow. readily accessible and loadable into
`and more powerful CPUs, Higher density and faster mass
`the computer's operating memory to direct the process of
`storage. and ever-larger operating systems.
`Because of the large size of operating systems today. such
`testing the computer's hardware and connectivity, and then
`as Windows™ and UNIX™ systems for example, it is
`loading all of the various operating code that is necessary for
`the computer to perform useful tasks. Typically this begin- 20 completely impractical to store the operating system on a
`floppy disk or in ROM. although some minim.um versions of
`ning code is called a basic input output system (BIOS),
`which includes a power-on self-test (POST) procedure, to
`some operating systems are available in ROM for special-
`assure that all circuits are active, properly connected. and
`ized purposes. Operating systems are therefore stored in
`functional before attempting to load and initiate all of the
`non-volatile mass storage. typically on a hard disk. In such
`code needed to operate.
`lS a system, at power on or reset, the BIOS ROM is accessed
`The BIOS in most instances is a relatively short code set
`first. loaded into RAM. and executed. After POST. a BIOS
`embedded in a non-volatile, read-only memory (ROM). such
`code causes the system to access a local hard disk at an
`as an electrically-erasable programmable read-only memory
`address. typically called the boot sector. where code is stored
`(EEPROM). accessible to the central processing unit (CPU)
`for directing loading of the operating system from the hard
`of a computer at the instant of power on. Partly because code 30 disk and finalizing preparation of the system for continuing
`operation. The operating system, which may be several
`can be accessed and executed from random access memory
`(RAM) more quickly than from read-only memory (ROM),
`megabytes of code. is then loaded. and the system is directed
`to a starting point for operator instructions. which may be
`the BIOS code is typically loaded immediately into RAM
`with an application loaded and ready to run. or at a point
`from ROM at power on, and executed from RAM.
`Although BIOS is fundamental to testing a computer's
`where an operator may select an application.
`operating equipment and basic BIOS functions continue to
`For those familiar with DOS operation the point that the
`user is able to select and manipulate operation is the familiar
`be used during subsequent operation, BIOS is not a sufficient
`system for continuing successful system operations. There
`DOS prompt. For those familiar with Microsoft Windows™
`are many functions, among them reading and writing data to 40 this point is the familiar interactive interface showing
`mass storage systems such a floppy disk drives (FDD), hard
`ICONS for program groups. For Apple Macintosh™ users
`disk drives (HDD) and CD-ROM drives, which have to be
`this point is the familiar Desktop graphics interface.
`loaded as well after executing the initial BIOS to render a
`As long as all hardware and software systems are
`computer fully operable. All of the code to make the
`operable. such an initiation sequence is routine. A hard disk
`computer capable of performing such basic functions is 4s drive, however. is a mechanical. device, and thus vulnerable
`referred to in the art as the Operating System (OS).
`to a much broader variety of potential difficulties than an IC
`In very early personal. computers, before widespread use
`ROM. Because of this mechanical. vulnerability. it often
`of hard disk drives (HDD), an operating system such as the
`happens that a system cannot boot because the boot disk
`IBM-compatible Disk Operating System (DOS) would typi-
`becomes inoperable. There are many other hardware failures
`cally be recorded on a floppy disk along with an application 50 that might occur other than the failure of a hard disk that
`such as a word processor or a spread-sheet program. A
`would prevent a PC from booting and operating as intended.
`floppy disk with DOS and a boot sector was called a Boot
`As well as hardware-only failures. there are many situa-
`disk, and the name is still used, al.though operating systems
`tions that can occur to render software corrupted, which
`and boot sectors are typically now recorded on hard disk
`condition may leave a PC unable to boot, such as corruption
`drives. One would place a boot disk in a floppy drive in the ss of the boot sector of the hard disk boot drive. or corruption
`computer, then turn the thing on. The BIOS would load from
`of a File Allocation Table (FKf).
`a resident ROM. perform a simple POST routine, then poll
`Early PCs were self-sufficient, stand-alone systems, com-
`the floppy drives (often there was only one) to find DOS.
`prising all of the hardware and software necessary to per-
`When Dos was located, the BIOS would cause it to be
`form intended functions. PCs at the time of the present
`loaded, and then present the DOS prompt for instruction 60 invention, however. are typically provided with some form
`from the user. BIOS code and DOS would remain in RAM
`of communication link to other computers. Most PCs at a
`for access by the CPU as needed for basic and routine
`minimum have a telephone modem connection, and may
`functions. The user could then boot the word processor or
`communicate with another computer over a telephone line in
`other application on the floppy and go to work.
`either an analog or a digital protocol.
`In this early and simple scenario, if DOS code on a boot 65
`PCs used in a business setting are often connected
`together in a local area network (LAN). whereby individual.
`disk were to become corrupted, the computer would not
`boot, and one could simply remove the boot disk from the
`workstations may have relatively fewer hardware compo-
`
`Patent Owner, Bot M8 LLC - Ex. 2001, p. 5
`
`

`

`5,732,268
`
`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 offending PC
`typically via one of the floppy drives, using a floppy boot
`disk with an operating system such as DOS that is small
`enough to store on the floppy, load diagnostic routines,
`detennine the fault or faults, and perform the needed repairs.
`1bis system-manager approach to maintenance is a time(cid:173)
`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(cid:173)
`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(cid:173)
`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(cid:173)
`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-
`5 puter. Code execution by the CPU is clirected from the first
`code portion 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 modem, analog
`10 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 first
`computer having a first CPU upon failure of the first
`computer to boot, comprising a second computer having a
`15 second CPU, the second computer connected to the first
`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
`(E-BIOS) in the first computer. Upon sensing failure of the
`20 first computer to boot, the E-BIOS establishes communica(cid:173)
`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 first computer and to
`be made available to the first CPU for execution, and
`2s wherein, with a copy of the slave kernel in the first 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 first computer from the second computer.
`An operator or automatic software at the second computer
`30 in this aspect may repair a corrupted boot sector on a disk
`drive of the first computer, or modify code of file allocation
`tables at the first computer.
`In another aspect a method of diagnosing and modifying
`code and data in read/write memory devices and mass
`35 storage devices of a first computer is provided. comprising
`steps of (a) establishing communication with the first com(cid:173)
`puter over a communication link from a diagnostic and
`repair computer; (b) loading and executing a master kernel
`at the diagnostic and repair computer; (c) downloading a
`40 slave operating system kernel to the first computer from the
`second computer; and ( d) accessing and modifying code and
`data on read/write memory devices and mass storage devices
`in the first computer through activity at the second computer.
`In an embodiment of the invention a basic input output
`The first computer may be caused to attempt to reboot after
`system (BIOS) is provided comprising a non-volatile 45 step (d). A method for establishing contact with a remote
`memory; a first code portion recorded in the non-volatile
`repair center computer upon failure of a local computer to
`memory and adapted for execution by a CPU to perform
`boot is provided in yet another aspect. comprising steps of:
`(a) sensing failure of the local computer to boot through
`startup functions for a computer, including initiating boot
`operations; and a second code portion recorded in the
`action of a first portion of code in an extended basic input
`non-volatile memory and adapted for execution by the CPU so output system (E-BIOS) installed and operable in the first
`to establish communication with a remote computer. Code
`computer; and (b) activating a communication link to the
`execution by the CPU is directed from the first portion to the
`remote repair center computer through action of a second
`second portion upon failure to complete the boot operations.
`portion of code in the E-BIOS. the second potion of code
`Communication with the remote computer may be estab-
`executed in response to the failure of the first computer to
`lished over a telephone link by operating a telephone modem ss boot.
`to dial a telephone number, using either an analog or digital
`The embodiments of the present invention and methods of
`line, and in some embodiments _Plural n~s . may be
`practicing the invention provide a unique system and pro-
`dialed in a priority sequence until a connection is estab-
`tocol for accessing, diagnosing and repairing computers that
`lished. Communication may be established as well over any
`fail to boot, without the expensive and time-consuming step
`network connection to remote computers.
`60 of sending a technician or engineer to the failed computer to
`In an alternative embodiment a computer is provided
`reboot the computer from a floppy, and to then diagnose and
`modify corrupted code and data.
`comprising a CPU; a mass storage device coupled to the
`CPU and having a boot code sector and operating sys~m
`RIEF DESCRIPTION OF THE DRAWINGS
`code recorded thereon; a read-only memory ROM device
`B
`coupled to the CPU; and a basic input output system (BIOS) 65
`FIG. 1 is a block diagram of an E-BIOS PC. an E-BIOS
`coupled to the CPU. the BIOS having a first code portion
`diagnostic center, and interconnection according to an
`recorded in the ROM device and adapted for execution by
`embodiment of the present invention.
`
`SUMMARY OF THE INVENflON
`
`Patent Owner, Bot M8 LLC - Ex. 2001, p. 6
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`

`5,732,268
`
`5
`FIG. 2 is a logic flow diagram of operation of an E-BIOS
`PC at boot up.
`FIG. 3 is a logic flow diagram of operation of diagnosis
`and repair after an E-BIOS PC and an E-BIOS diagnostic
`center are connected.
`
`5
`
`20
`
`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(cid:173)
`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(cid:173)
`tion is established, a human operator directs all interaction
`with the PC needing repair or modification 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 (1) a physical failure of the boot
`drive, (2) code corruption in the boot sector of the boot
`drive, (3) corruption of the file 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 offending 40
`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 45
`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 efficiency in response and service is provided by having
`the AS PCs respond first to incoming requests for service.
`The AS PCs in this case are programmed to look for and fix
`problems associated with the five 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 mare unusual and difficult 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 60
`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 flow diagram of operation of an E-BIOS 65
`PC at boot up, executing E-BIOS code. At step 21 power on
`is initiated. This may be from turning on the computer after
`
`35
`
`6
`a period of the computer being off, 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 sufficient 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
`10 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-
`15 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 specific code in the E-BIOS queries for a modem or
`a LAN connection, and finding one or the other, establishes
`communication with a remote E-BIOS diagnostic and repair
`25 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
`30 priority order. This is useful for situations wherein mainte(cid:173)
`nance personnel may be off-site, and there is no certainty as
`to availability. When a qualified person answers such a call,
`he or she returns a preprogrammed signal. In the case of a
`LAN connection, there may be a specific 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 specific embodiment, a user or an
`automatic software kernel at a remote unit 13 is notified 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 specific 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
`50 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(cid:173)
`tions where a service technician might be running another
`55 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
`offending PC.
`In some cases, for example wherein an E-BIOS PC needs
`service and the E-BIOS calls a remote designated location
`by modem, 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
`
`Patent Owner, Bot M8 LLC - Ex. 2001, p. 7
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`5,732,268
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`25
`
`35
`
`7
`the remote diagnostic and repair PC. In an alternative
`embodiment operation is by an automatic software kernel.
`F1G. 3 is a logic flow diagram of operations between a
`failed E-BIOS PC 11 and a remote diagnostics and repair PC
`13 (F1G. 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(cid:173)
`ments the downloading is initiated by the human operator. In
`automatic operation the downloading is directed by AS
`kernel 24 (F1G. 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 15
`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 preprogrammed integer, such as 20
`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(cid:173)
`lating the keyboard, screen, and floppy 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 floppy 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 floppy 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 40
`WindowsTM programs. Similar diagnostic programs are
`available and may be used in other embodiments. Opera(cid:173)
`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 kernel 45
`operating there, directed to the appropriate hardware devices
`and addresses at the failed PC. In this instance, when one
`uses the A: floppy 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 files on local media, running diagnostics (as
`described above), retrieval of system configuration
`infonnation, such as system registry, CMOS. desktop man(cid:173)
`agement files (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(cid:173)
`ated to accomplish the functions of the invention. It is well
`known to those with the skill in the art that the same
`
`8
`functions can be performed by code written in many differ(cid:173)
`ent ways. A variety of diagnostic and repair functions may
`be incotporated into different embodiments of the invention,
`and a number of these have been described above. Other
`5 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
`10 claims which follow.
`What is claimed is:
`1. A basic input output system (BIOS) comprising;
`a first 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
`first portion to the second portion upon failure to
`complete said boot operations.
`2. A BIOS as in claim 1 wherein the second portion directs
`the CPU to establish communication with a remote com(cid:173)
`puter through a telephone link by operating a telephone
`modem to dial a telephone number.
`3. A BIOS 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. A BIOS as in claim 1 wherein the second portion directs
`30 the CPU to establish communication with a remote com(cid:173)
`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.
`fi. 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 first 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 fi 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
`55 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 fi wherein the second portion
`60 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 first
`computer having a first CPU upon failure of the first
`computer to boot, comprising:
`a second computer having a seco