JP2000357093A - Computer system and reloading method for non-volatile memory - Google Patents

Abstract

PROBLEM TO BE SOLVED: To update a BIOS without activating a dedicated system program from an FD. SOLUTION: At the time of updating the BIOS, a BIOS updating driver 102 reserves and resisters callback in an operating system(OS) 103 so as to call back a BIOS updating processing part 102-1 just before ending shutdown processing of the OS 103. The OS 103 runs a shutdown processing program 104 and calls back the BIOS updating processing part 102-1 reserved and registered beforehand in the extension. At such a time point, the shutdown processing is not completely finished but almost all programs stop operating. In such a state, the BIOS updating processing part 102-1 updates the BIOS.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a computer system such as a personal computer, and more particularly to a computer system having a function of rewriting a BIOS program stored in an electrically rewritable nonvolatile memory and a method of rewriting the nonvolatile memory. About.

[0002]

2. Description of the Related Art In recent years, various laptop or notebook personal computers (PCs) which are easy to carry and can be operated by a battery have been developed. In this type of PC, BIOS (Basic
The BIOS is stored in a rewritable non-volatile memory such as a flash memory so that the BIOS can be updated by upgrading the input output system to a new version.

[0003] The BIOS is normally updated by powering on the PC with a floppy disk (FD) containing a new BIOS file for updating and a system program for updating the BIOS loaded in the PC, and updating the BIOS from the FD. This is performed by starting a system program. Activating the system from the FD in this way is the BI
This is because the BIOS may not be able to be correctly rewritten while other programs other than the OS update system program are operating.

That is, since various application programs and drivers are operating during the operation of the OS, if the address space allocated to the flash memory is accessed by the programs during the BIOS update processing, the flash memory of the flash memory is accessed. Danger of content being destroyed. In this case, not only can the BIOS not be updated to a new version, but also the BIOS
There is also a risk that S will not operate at all.

In order to avoid such danger, conventionally,
By automatically starting the BIOS update system program from the FD, the BIOS is updated in an environment completely different from the OS.
S update processing had to be performed.

[0006]

However, in recent notebook PCs, so-called FDD-less PCs without a floppy disk drive (FDD) have been increasing in order to improve portability. Such a PC
However, the conventional BIOS update method of starting the BIOS update system program from the FD cannot be applied. Also, even if the PC is equipped with an FDD, if a new BIOS file for updating is provided from a medium other than the FD, such as a network, the file must be stored once again in the FD. Updating will take a lot of time and effort.

[0007] The present invention has been made in view of the above-mentioned circumstances, and enables rewriting of a non-volatile memory, such as BIOS updating, to be performed safely in an operating environment of an operating system.
It is an object of the present invention to provide a computer system capable of executing processing such as S update and a method for rewriting a nonvolatile memory.

[0008]

In order to solve the above-mentioned problems, a computer system according to the present invention comprises an electrically rewritable nonvolatile memory and an updating process for rewriting the nonvolatile memory at a predetermined timing. Call reserving means for reserving and registering the update processing call to the operating system so as to be called from the operating system; and for rewriting the nonvolatile memory in response to the update processing call from the operating system. And updating means for executing the updating process and updating the information stored in the nonvolatile memory to new information.

In this computer system, the update processing call is registered in advance in the operating system, so that the operating system can be operated at a specific timing, for example, at the time of operating system shutdown processing or bootstrap processing. When almost all programs are stopped even in the environment where is running, the update process can be executed in response to a call from the operating system. Therefore, rewriting of the non-volatile memory such as BIOS update can be performed safely under the operating environment of the operating system, and even a PC without FDD can easily execute processing such as BIOS update.

[0010] Particularly, it is preferable that the BIOS be updated during the execution period of the shutdown process, preferably immediately before the end of the shutdown process. Normally, in order for the updated BIOS to operate normally, BIOS
After updating the S, it is necessary to restart the operating system to initialize the system once. However, if the BIOS is updated during the shutdown process, the system is automatically initialized the next time the system is started. This is because extra restart operation can be omitted. Also, immediately before the end of the shutdown process, the BIOS
By performing the update, it is possible to further reduce the possibility that another program is being executed during the BIOS update, and it is possible to improve safety.

Preferably, the call reservation means is configured to be controllable from an application program executed on an operating system. This allows the user to control the operation of the call reservation means through the application program.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of a computer system according to an embodiment of the present invention. This computer system is a notebook-type personal computer (PC) that can be driven by a battery. As shown in the figure, the main body of the PC includes a processor bus 1, a PCI bus 2, an ISA bus 3, a CPU 11, a host-PCI bridge 12, and the like. , Main memory 13, display controller 14, PCI
-ISA bridge 15, I / O controller 16, communication interface 17, flash BIOS-ROM1
8, a power supply controller 19, a keyboard controller (KBC) 20, a CMOS memory 21, and the like.

The CPU 11 controls the operation of the entire PC, and the system 11 of the BIOS-ROM 18
OS (Basic Input Output Sys)
tem) to execute the operating system and various other programs loaded into the main memory 13. In the system of the present embodiment, a BIOS update program and a BIOS update driver are prepared as software for rewriting the system BIOS of the BIOS-ROM 18, and when updating the system BIOS, the BIOS update program and the BIOS update The driver is executed by the CPU 11. These BI
Both the OS update program and the BIOS update driver are an application program and a driver program configured to operate under the operating environment of the operating system (OS), and the BIOS update is executed under the operating environment of the operating system (OS). be able to.

In this case, the execution of the BIOS update is performed, for example, immediately before the end of the shutdown processing of the operating system or immediately after the end of the bootstrap processing.
This is performed when almost all programs are stopped even in the environment where the operating system is running. Since various application programs and drivers are operating while the OS is operating, if the flash BIOS-ROM is
18 is accessed by those programs, the flash BIOS-RO
There is a risk that the contents of M18 will be destroyed. However, as in the present embodiment, by performing the BIOS update process in a state where almost all the programs are stopped, the BIOS is updated.
OS update can be performed safely.

The host-PCI bridge 12 is a bridge device for connecting the CPU bus 1 and the PCI bus 2 bidirectionally, and has a built-in memory control function for controlling access to the main memory 13. Main memory 1
Reference numeral 3 stores an operating system (OS), an application program / driver to be processed, user data created by the application program / driver, and the like.

The display controller 14 has an image memory (V
The display data drawn on the (RAM) 141 is displayed on one or both of the LCD 142 and the external CRT 143 provided in the main body of the PC. This display controller 1
4 can operate as a bus master of the PCI bus 2.

The PCI-ISA bridge 15 is a bridge connecting the PCI bus 2 and the ISA bus 3, and is a PCI-ISA bridge.
It can operate as a bus master of the bus 2. The PCI-ISA bridge 15 has a function of controlling various I / Os and memories on the ISA bus 3 under the control of the CPU 11. Flash BIOS-ROM18
Is rewritten by erasing the contents of the flash BIOS-ROM 18 and then writing a new BIOS image to the flash BIOS-ROM 18.

The I / O controller 16 has a built-in bus master IDE controller for controlling IDE devices such as the HDD 161 used as secondary storage. The bus master IDE controller can operate as a bus master for data transfer between the HDD 161 and the main memory 13. Also, the I / O controller 16 can control a DVD drive or a CD-ROM drive.

The communication interface 17 is for communicating with a computer on the Internet via a public network, for example, and is realized by a modem or an ISDN card. When performing a BIOS update, the communication interface 17 transmits a new updated B
Used to download an IOS file from a web server on the Internet. The downloaded updated BIOS file is stored in the HDD 161.

The flash BIOS-ROM 18 is for storing the system BIOS as described above, and is a flash memory (flash EEPROM) which is an electrically rewritable non-volatile memory so that the BIOS can be updated by software. ). The system BIOS executes POST (PowerON Se) executed when the PC is powered on or restarted.
lf Test) routine, a system driver group for controlling various I / O devices, a BIOS setup routine for setting a system environment, and the like, which are used to directly control hardware in a PC. Can be

The power supply controller 19 is for controlling the power on / off of the PC, and includes the on / off of a power switch, the remaining capacity of a battery, the connection / removal of an AC adapter, and the on / off of a display panel open / close detection switch.
It has a function to monitor the status such as off. A keyboard controller (KBC) 20 controls a keyboard and a mouse. The CMOS memory 21 is a memory for storing setting information of various hardware and the like, and is backed up by a unique battery.

(Software Structure for Updating BIOS) Next, with reference to FIG. 2, a software structure for realizing the BIOS updating method of this embodiment will be described. In the present embodiment, roughly two levels are prepared as privilege levels for executing the program code. One is ring level 1 called user mode or application, and the other is ring level 0 called kernel mode. The protection mechanism is “1”. It becomes higher in the order of “0”, and the kernel mode of the ring level 0 is the highest privilege level. The code of the process executed in the kernel mode of the ring level 0 can access all memory address spaces, but the memory address space of the code executed of the process executed in the user mode of the ring level 1 is restricted to a specific space. You.

In the ring level 1 user mode, executable instructions are also restricted. Such a privilege mode is realized by a protect mode which is one of the operation modes of the CPU 11, a process management function of the operating system, and the like.

Normally, application programs and the like are executed in a ring level 1 user mode, and a kernel section and a driver of an operating system (OS) are executed in a ring level 0 kernel mode.

As described above, in this embodiment, the BIO
Software for rewriting the system BIOS in the S-ROM 18 includes a BIOS update program 101.
And a BIOS update driver 102 are provided.

The BIOS update program 101 allows the user to specify the location of an updated BIOS file,
This is an application program that provides a user interface for giving an instruction to execute S update, and the code of the process is executed in a user mode (ring level 1). The BIOS update program 101 has a function of issuing a BIOS image load request to the BIOS update driver 102, a function of issuing a shutdown request to the operating system 103, and the like.

The BIOS update driver 102 is executed in a kernel mode (ring level 0). In response to a load request from the BIOS update program 101, the BIOS update driver 102
A function of loading an S image from the HDD 161 onto the main memory 13 and a function of making a reservation registration of a call (callback) of the BIOS update processing unit 102-1 in the BIOS update driver 102 to the operating system 103 are provided. . Operating system 10
In the case where the BIOS update processing unit 102-1 has been registered to be called back immediately before the end of the shutdown process 3, the BIOS update processing unit 102-1 is called back by the shutdown processing program 104 of the operating system 103. . With this, the OS
The BIOS can be updated in a state where almost all programs and devices are stopped while being operated.

(Flow of BIOS Update Process) Next, a flow of a series of processes executed by the BIOS update program 101 and the BIOS update driver 102 in FIG. 2 will be described with reference to FIG.

When performing a BIOS update, the user:
First, the BIOS update program 101 is executed, and location information such as a file name of a new update BIOS file is specified to the BIOS update program 101. BI
The OS update program 101 executes a designated update BIOS
A request to load a file (BIOS image) into a buffer in the kernel space prepared on the main memory 13 is sent to the BI
It is issued to the OS update driver 102. The BIOS update driver 102 checks the validity of the specified updated BIOS file, and after confirming the validity, loads the binary data (BIOS image) of the specified updated BIOS file into the buffer.

After that, the BIOS update driver 102
Callback reservation is registered with the operating system 103 so that the BIOS update processing unit 102-1 is called back immediately before the shutdown processing of the operating system 103 ends. When the reservation registration process is performed by the operating system 103,
Control returns to the BIOS update driver 102 and the BIOS
From the OS update driver 102 to the BIOS update program 1
Control returns to 01.

When the user specifies that the operating system 103 should be shut down immediately, the BIOS update program 101
When the control is returned from the S update driver 102, a shutdown request is issued to the operating system 103. The operating system 103 executes the shutdown processing program 104, and as an extension of the shutdown processing program 104, the BIOS update processing unit 102-1 previously registered and reserved.
Call back. That is, an interrupt to the BIOS update processing unit 102-1 occurs during the shutdown processing. At this point, the shutdown processing of the operating system 103 has not been completely completed, but the operation of the application programs and most other device drivers has been stopped.

In response to the callback from the operating system 103, the BIOS update processing unit 102-1 rewrites the contents of the flash BIOS-ROM 18 with the BIOS image loaded in the buffer in the kernel space. When the rewriting process of the flash BIOS-ROM 18 is completed, the operating system 103
The control returns to. Then, the PC is restarted with the shutdown processing completely completed. The restart of the PC, that is, the start of the bootstrap process of the operating system 103 is performed by, for example, the flash BIOS-R
After the rewriting process of the OM 18, the BIOS update processing unit 102
-1 may be issued to the operating system 103 by issuing a reboot request, or after exiting from the callback reservation processing, the BIOS update program 1
01 to the operating system 103 is not a shutdown request, but a shutdown request.
This can also be realized by making a reboot request.

(BIOS Update Program) The flowchart of FIG. 4 shows the processing procedure of the BIOS update program 101. When the BIOS update program 101 is executed, a screen for prompting the user to input file location information such as the file name of the updated BIOS file is presented, and the updated BIOS file is input on the screen (step S101). Next, the BIOS update program 101 updates the update BIOS specified in step S101.
After reading the OS file from the HDD 161 (step S102), the BIOS update driver 102
Issue an IOS image load request (step S10)
3). Then, the BIOS update program 101
When control is returned from the S update driver 102, the BIOS
The return value from the update driver 102 is checked to determine whether or not the request to the BIOS update driver 102 has been normally processed (step S104). If successful, BI
The OS update program 101 determines whether the user has specified immediate shutdown (step S105), and issues a shutdown request to the operating system 103 when shutting down immediately (step S106). ).

(BIOS Image Loading Process of BIOS Update Driver) The flowchart of FIG. 5 shows a procedure of the BIOS image loading process executed by the BIOS update driver 102. BIOS update driver 1
In step S02, when the BIOS image load request is received, first, the validity of the BIOS image of the updated BIOS file is checked to determine whether or not the BIOS image is correct (steps S111 and S112).
This validity check is performed, for example, using information recorded in the header of the updated BIOS file.

That is, as shown in FIG. 6, ID information for identifying the PC corresponding to the BIOS image is added to the header of the updated BIOS file.
Using the ID information, the BIOS update driver 102 checks whether the BIOS image is a BIOS corresponding to the PC.

If the inspection does not find any problems,
It is determined that the image is a correct BIOS image. In this case, the BIOS update driver 102 executes the BIOS update immediately before the end of the shutdown processing of the operating system 103.
Callback reservation is made to the operating system 103 so that the OS update processing unit 102-1 is called back (step S113), and the BIOS image requested to be loaded is loaded into a buffer in the kernel space (step S113). S114). Step S1
Either of the processes of S13 and S114 may be performed first.
The callback registration is performed by registering the function name (BIOS update processing unit 102-1) to be called back in the operating system 103.

Thereafter, the BIOS update driver 102
The result of the execution process in response to the BIOS image load request is returned to the BIOS update program 101, and the control is returned to the BIOS
The process returns to the S update program 101 (step S115).

(Shutdown Process of Operating System) FIG. 7 is a flowchart showing a shutdown process program 104 of the operating system 103.
2 shows a procedure of a shutdown process executed by the server. When the shutdown request is issued, the shutdown processing program 104 is executed, and the shutdown processing of the operating system 103 is started (step S121). Shutdown request is BIOS
It is issued not only from the update program 101 but also when a user performs a normal shutdown operation such as a power switch off. In either case, the content of the shutdown processing executed by the shutdown processing program 104 is the same, and processing for stopping the operation of the application program, the driver, and the like is performed. Then, when almost all the programs except the kernel unit of the operating system 103 are stopped, a function (callback function) reserved and registered in the operating system 103 is called and executed (step S122). In the present embodiment, the BIO
Since the S update processing unit 102-1 is registered and registered to be called back, the BIOS update processing unit 102-1 is registered.
Is called by the operating system 103 and executed.

(BIOS Update Processing) The flowchart of FIG. 8 shows the procedure of the BIOS update processing executed by the BIOS update processing unit 102-1. First, the BIOS update processing unit 102-1 first executes the flash BIOS-RO
After erasing the contents of M18, the BIOS image prepared on the buffer in the kernel space is
Writing to the S-ROM 18 (step S131). BI
When the writing of the OS image is completed, the BIOS update processing unit 102-1 reads the BIOS image from the flash BIOS-ROM 18, compares the BIOS image with the BIOS image prepared in the buffer in the kernel space, and succeeds in updating the BIOS. It is determined whether or not it has been performed (steps S132, S133). If the BIOS update has not been successful, the process from step S131 is retried. If the BIOS update is successful,
Is performed (step S134).

As described above, in the present embodiment, by performing the BIOS update processing during the shutdown processing of the operating system 103, the BIOS update can be performed under the operating environment of the operating system 103, and the FDD can be performed. It is possible to safely update the BIOS without starting a dedicated system for updating the BIOS.

(Flow of BIOS Update Process: Part 2) Next, referring to FIG.
A series of processing procedures when the BIOS is updated immediately after the end of the boot process will be described.

When performing a BIOS update, the user:
First, the BIOS update program 101 is executed, and location information such as a file name of a new update BIOS file is specified to the BIOS update program 101. BI
The OS update program 101 executes a designated update BIOS
A request to load a file (BIOS image) into a buffer in the kernel space prepared on the main memory 13 is sent to the BI
It is issued to the OS update driver 102. The BIOS update driver 102 checks the validity of the specified updated BIOS file, and after the validity is confirmed, records the specified updated BIOS file name. After this, BIOS
The update driver 102 is installed in the operating system 10
A callback reservation is registered with the operating system 103 so that the BIOS update processing unit 102-1 is called back immediately after the end of the bootstrap process of No. 3. When the reservation registration process is performed by the operating system 103, the BIOS update driver 102
Then, the control is returned from the BIOS update driver 102 to the BIOS update program 101.

The BIOS update program 101 shuts down the operating system 103 when control is returned from the BIOS update driver 102 if the user has specified that the operating system 103 be immediately shut down and rebooted. -Issue a reboot request. The operating system 103 is a shutdown processing program 104
And then execute a bootstrap process (reboot process). Then, as an extension of the bootstrap processing, the BIOS update processing unit 102 previously reserved and registered
Call back -1. That is, an interrupt to the BIOS update processing unit 102-1 occurs immediately after exiting the reboot process. At this point, most of the application programs have been stopped. In addition, by executing the call of the BIOS update processing unit 102-1 prior to the installation (load) processing of another driver, not only the application program but also the
The BIOS update processing unit 102-1 can be executed in a state where almost all other drivers are stopped.

In response to the callback from the operating system 103, the BIOS update processing section 102-1 rewrites the contents of the flash BIOS-ROM 18 with the BIOS image of the recorded updated BIOS file name. When the rewriting of the flash BIOS-ROM 18 is completed, the BIOS update processing unit 102-1 reboots the operating system.

(BIOS File Package) In the above description, the BIOS update program 101 and the BIOS update driver 102 are stored separately from the updated BIOS file.
Although the case where the BIOS update program 101 and the BIOS update driver 102 are used as an installation in C is illustrated, it is also possible to download the BIOS update program 101 and the BIOS update driver 102 from the network together with the update BIOS file. In this case, what is downloaded from the network is as shown in FIG.
The BIOS file package is as follows.

The BIOS file package includes B
IOS update program 101, BIOS update driver 1
02 and an archive file containing the BIOS image, and the BIOS update programs 101 and B
It includes an IOS update driver 102 and a setup program for installing a BIOS image on a PC. By executing this setup program, the BIOS update processing can be automatically performed. The procedure in this case is shown in FIG.

First, through the web browser, the BIOS
The file package is downloaded from the web server (Step S201). Downloaded BIO
The S file package is automatically executed by the web browser (step S202), and after the BIOS file package is automatically decompressed (step S20).
3), execution of the setup program is started (step S204). When the setup program is executed, the BIOS update program 101 is installed and the BIOS
Registration of the OS update driver 102 and the like are performed. Then, the BIOS update program 101 is automatically started (step S205), and the BIOS update process is performed in the same procedure as in FIG. 3 or FIG. The only difference from FIG. 3 or FIG. 9 is that the user does not need to specify the location of the BIOS image. All other points are the same as those in FIG. 3 or FIG.

The BIOS file package shown in FIG. 10 (or the BIOS update programs 101 and B
It is also possible to prepare a recording medium on which the IOS update driver 102 is recorded, and to introduce the BIOS file package (or only the BIOS update program 101 and the BIOS update driver 102) into the PC through the recording medium.

In this embodiment, the flash BIO
Although the rewriting of the BIOS stored in the S-ROM 18 has been described, the program or data stored in the electrically rewritable nonvolatile memory is described below.
It can be safely rewritten with a new program or data in the same procedure as the BIOS update. For example, CM
It can be used for updating system setting information stored in the OS memory 21.

Further, in the BIOS update method according to the present embodiment, it is important to update the BIOS in a state where almost all programs and devices are stopped while operating under the OS operating environment. The BIOS may be updated not only at the time of booting, but also when the OS transitions to the sleep state or when the OS returns from the sleep state.

[0052]

As described above, according to the present invention,
Rewriting of the non-volatile memory such as BIOS update can be performed safely under the operating environment of the operating system, and even a PC without FDD can easily execute processing such as BIOS update.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a computer system according to an embodiment of the present invention.

FIG. 2 is an exemplary view for explaining a software structure for realizing a BIOS update method used in the system of the embodiment;

FIG. 3 is an exemplary view showing the flow of a BIOS update process executed in the system of the embodiment.

FIG. 4 is an exemplary flowchart illustrating a processing procedure of a BIOS update program used in the system of the embodiment.

FIG. 5 is an exemplary flowchart illustrating a procedure of a BIOS image loading process of a BIOS update driver used in the system of the embodiment.

FIG. 6 is an exemplary view showing the structure of a BIOS file used in the system of the embodiment.

FIG. 7 is an exemplary flowchart illustrating the procedure of shutdown processing of the operating system in the system of the embodiment.

FIG. 8 is an exemplary flowchart illustrating a procedure of a BIOS update process by a BIOS update driver used in the system of the embodiment.

FIG. 9 is an exemplary view showing a second example of the BIOS update process executed in the system of the embodiment.

FIG. 10 shows a BIOS used in the system of the embodiment.
The figure which shows the structure of a file package.

FIG. 11 is an exemplary flowchart showing the procedure of a BIOS update process using the BIOS file package of FIG. 10;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... CPU 12 ... Host-PCI bridge 13 ... Main memory 15 ... PCI-ISA bridge 16 ... I / O controller 17 ... Communication interface 18 ... Flash BIOS-ROM 21 ... CMOS memory 101 ... BIOS update program 102 ... BIOS update driver 102 -1 BIOS update processing unit 103 Operating system 104 Shutdown program 161 HDD

Claims (15)

[Claims] 1. An electrically rewritable nonvolatile memory, and a call for the update process to the operating system such that an update process for rewriting the nonvolatile memory is called from an operating system at a predetermined timing. Call reserving means for reserving and registering the update processing; and executing update processing for rewriting the nonvolatile memory in response to a call for the update processing from the operating system, and newly updating information stored in the nonvolatile memory. A computer system, comprising: updating means for updating information. 2. The call reservation means according to claim 1, wherein said operating system is configured to call said updating process for rewriting said nonvolatile memory when said operating system shutdown process is performed. 2. The computer system according to claim 1, wherein a call for updating is registered. 3. The operating system according to claim 2, wherein the call reservation unit is configured to execute a bootstrap process of the operating system so that an update process for rewriting the nonvolatile memory is called from the operating system. 2. The computer system according to claim 1, wherein a call for the update process is registered. 4. The non-volatile memory stores a BIOS program for hardware control of the computer system, and the call reservation unit calls the update process for updating the BIOS program. 2. The system according to claim 1, wherein the update registration means updates the BIOS program stored in the nonvolatile memory to a new BIOS program prepared on the computer system. Computer system. 5. The call reservation means reserves and registers a call for an update process for updating the BIOS program to the operating system in response to a request from an application program executed on the operating system. The computer system according to claim 4, wherein: 6. A computer system having an electrically rewritable nonvolatile memory in which a BIOS program is stored, wherein the computer program is configured to be operable under an operating environment of an operating system, and stores the BIOS program stored in the nonvolatile memory. BIOS updating means for executing an updating process for updating, and controlling means for causing the BIOS updating unit to execute the updating process when a shutdown process of the operating system is performed or a bootstrap process is performed. A computer system comprising: 7. The control unit calls the update process to the operating system so that the update process is called from the operating system when a shutdown process or a bootstrap process of the operating system is performed. 7. The computer system according to claim 6, further comprising means for registering a reservation. 8. A method for rewriting an electrically rewritable nonvolatile memory provided in a computer system, wherein an update process for rewriting the nonvolatile memory is called from an operating system at a predetermined timing. In the normal operation of the operating system, the update process call is reserved for the operating system, and the update for rewriting the nonvolatile memory is performed in response to the update process call from the operating system. Performing a process and updating information stored in said non-volatile memory with new information. 9. Reserving and registering a call for the update processing to the operating system so that the update processing is called from the operating system when the shutdown processing of the operating system is performed; 9. The method according to claim 8, wherein an update process for rewriting the nonvolatile memory is performed when a shutdown process is performed. 10. The operating system, wherein the updating process is reserved and registered in the operating system so that the updating process is called from the operating system when the operating system bootstrap process is performed. 9. The method according to claim 8, wherein an update process for rewriting the nonvolatile memory is performed when the bootstrap process is performed. 11. The non-volatile memory stores a BIOS program for hardware control of the computer system. The non-volatile memory stores a BIOS program in response to a call for the update process from the operating system. 9. The method according to claim 8, wherein the BIOS program is updated with a new BIOS program. 12. A rewriting method for updating a BIOS program stored in an electrically rewritable non-volatile memory provided in a computer system, the rewriting method for rewriting a BIOS program in the non-volatile memory. The update process call is reserved for the operating system so that the process is called when an operating system shutdown process is performed or a bootstrap process is performed. A method of updating a BIOS program stored in the non-volatile memory with a new BIOS program in response to a call for an update process. 13. A method for updating a BIOS program stored in an electrically rewritable nonvolatile memory provided in a computer system, the method comprising: updating a new BIOS program under an operating environment of an operating system. An update program operably configured to update a BIOS program in the non-volatile memory; and installing the file package in the computer system, and executing the update program. And updating the BIOS program in the non-volatile memory with the new BIOS program. 14. A recording medium on which a computer program for rewriting an electrically rewritable nonvolatile memory provided in a computer system is recorded, wherein the computer program is an update for rewriting the nonvolatile memory. A procedure for making a reservation registration of the update processing call to the operating system during normal operation of the operating system so that the processing is called from the operating system at a predetermined timing; and a call to the update processing from the operating system. Executing an update process for rewriting the non-volatile memory in response to the non-volatile memory, and updating information stored in the non-volatile memory to new information. 15. The procedure of registering a reservation includes reserving a call for the update process to the operating system such that the update process is called from the operating system when a shutdown process of the operating system is performed. 15. The recording medium according to claim 14, wherein an update process for rewriting the non-volatile memory is executed upon registration and when a shutdown process of the operating system is performed.