JPH11306007A - Method and system for bios rewriting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a basic input output system(BIOS) rewriting method and its system which permit activation of a system from the next time onward even if rewriting of a BIOS data fails. SOLUTION: A flash ROM is divided into blocks 20 and 21 for storing a BIOS and a block 22 for storing status information, a block to read the BIOS on the basis of information first read from the block 22 at the time of activation is selected and the system is started, and a block different from ones used for starting the system out of the blocks 20 and 21 that store the BIOS is rewritten by a new BIOS at the time of BIOS rewriting. Then, the device is equipped with an address/boot conversion control means (1) which controls so that the BIOS is read out of the block in which the BIOS is rewritten anew at the time of next system start and the system is started at the next time of starting the system only when rewriting is normally performed by the new BIOS.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a BIOS (basic input / outpu) for an information processing device such as a personal computer.
In particular, the present invention relates to a BIOS rewriting method suitable for a system in which a BIOS is stored in a flash ROM that can be erased and written in block units.

[0002]

2. Description of the Related Art When a BIOS, which is a basic software system for controlling hardware functions of an information processing apparatus such as a personal computer, is stored in a mask ROM or the like, the update is performed by exchanging the mask ROM. 2. Description of the Related Art Recently, an information processing apparatus that stores a BIOS in a rewritable flash ROM in units of blocks and enables updates such as modification of the BIOS and addition of functions has been commercialized. In this case, in order to rewrite the BIOS, the BIOS is updated by the user himself or when a maintenance contract is made, the maintenance is performed by a maintenance person.

[0003]

SUMMARY OF THE INVENTION However, BIO
In order to rewrite S, it is necessary to obtain a BIOS, activate a predetermined rewriting tool, and perform the rewriting in accordance with a predetermined procedure. Without a certain degree of specialized knowledge, rewriting may fail.

Further, the power supply is accidentally turned off during rewriting, or the BIOS data in the flash ROM is erased by a rewriting tool, and then the BIOS is stored in the flash ROM.
If the writing of S is not performed normally, the system cannot be started up normally next time. This is because, when the system is started, first, the BIOS data is read from the flash ROM and the system is started up. However, if the BIOS data is lost or damaged, the system cannot be started. It is.

As a BIOS rewriting method, for example, Japanese Patent Laid-Open No. 8-69376 discloses a BIOS ROM rewriting method.
BIO for preventing operation from being disabled again even if power is cut off during rewriting of contents
The S rewriting device includes an address switching circuit that switches, using a jumper switch, which of the upper and lower parts of the same capacity of the nonvolatile memory element stored in the BIOS is stored by using a jumper switch. The BIOS is divided into a basic part and an extended part. The basic part is rewritten by writing the new basic part into the part storing the old extended part, and after completing the writing, exchanging the upper and lower parts of the nonvolatile memory element in circuit, and then replacing the old BIOS basic part. A method has been proposed in which a stored block is erased and a new extension is written. As will be made clear later,
The present invention provides a system different from the rewriting system described in, for example, JP-A-8-69376.

[0006] Therefore, the present invention has been made in view of the above-mentioned problems, and its object is to provide, for example, a BIOS.
It is an object of the present invention to provide a BIOS rewriting method and method that enable the system to be started after the next time even if data rewriting fails.

[0007]

In order to achieve the above object, a BIOS rewriting method according to the present invention reads a rewritable nonvolatile semiconductor memory device in a plurality of areas each storing a BIOS and at system startup. The system is divided into an area for storing status information including information for determining the area, and at the time of system startup, first, a block from which the BIOS is read is selected based on the information read from the area for storing the status information, and a BIOS is read from the selected block.
Is read and the system is started up. At the time of BIOS rewriting, an area other than the area used for system start-up among a plurality of areas storing the BIOS is replaced with a new BIOS.
Only when the rewriting by the OS and the rewriting by the new BIOS are performed normally, the next time the system starts up, reads out the BIOS from the area where the new BIOS has been rewritten and starts up the system.

Further, in the BIOS rewriting method according to the present invention, the rewritable nonvolatile semiconductor memory device includes a first area, a second area storing a BIOS, and a third area storing status information which is read first when the system is started. And at the time of system startup, the status information stored in the third area in the nonvolatile semiconductor memory device is first read, and the address is controlled to control any one of the first and second areas. The system is started by reading the BIOS data written in the area, and when rewriting the BIOS, the first and second areas in the nonvolatile semiconductor memory device are used to start and stop the system. Controls the writing of a new BIOS to a different area, and further sets the third area from either the first or the second area. Configured to include an address / boot conversion control means for updating the latest status information regarding launch Temu.

[0009]

Embodiments of the present invention will be described below. According to the present invention, the flash ROM is divided into a block for starting up the system and a block for rewriting the BIOS, and only when the rewriting is normally performed, the system is started from the block in which the BIOS is newly rewritten. Is controlled as follows.

More specifically, the BIOS rewriting method according to the present invention, in a preferred embodiment, comprises: a flash ROM for storing a BIOS; a block for storing status information which is first read at system startup;
The system is divided into a plurality of blocks for storing the BIOS, and at the time of system startup, a block for reading the BIOS is selected from information read from the block for storing status information, and the system is started by reading the BIOS from the selected block. At the time of BIOS rewriting, a block different from the block used for system startup (hereinafter referred to as “original block”) is rewritten with a new BIOS, and if the rewriting of the new BIOS is performed normally, status information is stored. When the BIOS is rewritten normally at the next system start-up, the contents of the block to be updated
Read out the IOS and start up the system,
When the rewriting of the BIOS fails, control is performed so that the BIOS is read from the original block and the system is started.

In a preferred embodiment of the BIOS rewriting method of the present invention, referring to FIG. 1, a flash ROM (2) includes first and second blocks (20, 21) for storing a BIOS and a system configuration. The third block (2
2) When the system is started, first, the status information stored in the third block is read, and the address is controlled to write the BIOS in the area of either the first or second block. The system is started by reading the data, and when rewriting the BIOS, of the first and second blocks of the flash ROM,
A new BIOS is written to an area different from the area used to start up the system (for example,
When the system is started up in the block, the BIOS is rewritten in the second block).
An address / boot conversion control means (1) for updating the third block with the latest status information regarding which one of the first and second blocks starts up the system.

That is, the address / boot conversion control means (1) controls the block (2) in the flash ROM (2).
There is provided functional means for controlling an address based on the status information stored in 2) and controlling the system to start up from either the block (20) or the block (21) BIOS data.

At the time of rewriting the BIOS, the address / boot conversion control unit (1) controls the writing to be performed on a block different from the block used for starting up the system. There is provided a functional unit for performing control to change to the latest status information.

In the embodiment of the present invention, the flash ROM includes a block in which a plurality of pieces of BIOS data are stored. At the time of BIOS rewriting, the BIOS is rewritten to a block different from the block where the system was started. Since the blocks used to start up the system are not erased or written, the system may not start up at the next system start-up even if BIOS rewrite fails. It can be avoided reliably. Hereinafter, the present invention will be described in detail with reference to examples.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the configuration of one embodiment of the present invention.

Referring to FIG. 1, one embodiment of the present invention is:
Between the address, data and control lines connected to a flash ROM 2 (batch erase type electrically erasable and writable read-only memory) in which BIOS data is written and the stored contents are retained even when the power is turned off. And an address / boot conversion control unit 1 for converting an address and a block to be read in the flash ROM 2.

The flash ROM 2 has two blocks 20 and 21 in which BIOS data is written and is readable and writable, a block 22 which stores status information of the flash ROM 2 and is read first when the system is started, and It is provided with.

FIG. 2 is a block diagram showing an example of the configuration of the address / boot conversion control unit 1 in one embodiment of the present invention. With reference to FIG. 2, a detailed configuration of the address / boot conversion control unit 1 in one embodiment of the present invention will be described.

A status read / write unit 10 connected to address, data and control lines for controlling read / write (write) of status information from a block 22 of the flash ROM 2;
A status (Status) register 12 capable of storing a value read by 0 and capable of reading / writing, and an address conversion unit 11 for reading and determining the status register 12 and converting an address are provided.

The status read / write unit 10 is a block 2
When starting up the system from the BIOS data of 0 or 21, first, status information is read from the block 22 and stored in the status register 12, and after rewriting is completed, the set value of the status register 12 is stored in the block 22 as a new status. It has a function to write as information.

The status register 12 is a block 20
"0" when the system has been started up with the BIOS data of "1", and "1" when the system has the BIOS data of block 21.
Is set, and an update flag 121 is set to “1” in the case of the rewrite mode and “0” otherwise.

When the value of the update flag 121 is “0” and the value of the boot flag 120 is “0”, the address translator 11 sends the (2) update flag When the value of 121 is “0” and the value of the boot flag 120 is “1”,
Translate the address to access block 21;
When the value of the update flag 121 is “1”, the update flag 121 has a function of converting an address so as to access a block opposite to the block used at the time of booting.

FIG. 3 is a flowchart for explaining the operation of one embodiment of the present invention. The operation of the embodiment of the present invention will be described with reference to FIGS.

First, when the power of the system is turned on (step S1), the status reading / writing unit 10
And reads the status information from the status register 12 (step S2). The address conversion unit 11 includes a boot flag 12
If the value of 0 is "0", block 20 is read, and if it is "1", block 21 is read and the system is started.

Thereafter, rewriting starts from a boot medium such as a boot FD (floppy disk) or boot disk in which new BIOS data and a rewriting tool are stored.

When the BIOS rewrite starts, the status read / write unit 10 sets the update flag 121 of the status register 12 to "1" in order to enter the rewrite mode (step S3).

The address converter 11 converts the address of the block to be rewritten according to the value of the boot flag 120 of the status register 12. If the update flag 121 is “1” and the boot flag 120 is “0”, the
Rewrite OS data. If the boot flag 120 is “1”, it is converted to the address of the block 20 and the BIOS
The data is rewritten (steps S5 and S6).

When the rewriting of the BIOS ends normally,
The status read / write unit 10 updates the update flag 12
1 is set to "0", and the value of the boot flag 120 is inverted to "1" if it is "0" and "0" if it is "1" (step S9).
Is written (step S10).

Thus, at the next start-up, a new B
The IOS data can be started from the rewritten block.

If the BIOS rewrite is not completed normally, the reset is performed (step S5).
8) Since the boot flag 120 has not been rewritten, the BIOS of the block in which the system has been started up to now is
Since the system is started using the data, it is possible to avoid a situation in which the system cannot be started even when the BIOS rewrite fails.

Another embodiment of the present invention will be described in detail with reference to the drawings. FIG. 4 is a block diagram showing an example of the configuration of the address / boot conversion control unit 1 according to the second embodiment of the present invention. With reference to FIG. 4, a detailed configuration of the address / boot conversion control unit 1 in one embodiment of the present invention will be described.

Referring to FIG. 4, in the second embodiment of the present invention, the address / boot conversion control unit 1 of the embodiment shown in FIG. Immediately after being turned on, a flag switch 3 that can be switched directly is connected.

The flag switch 3 sets the boot flag 120 to a fixed value of “0” or “1”. Thereafter, the address conversion unit 11 sets the boot flag 12
According to the value of 0, the BIOS data of either the block 20 or 21 is read and the system is started.

In a second embodiment of the present invention, in a system in which the hardware is the same but the CPU and each I / O setting are different, the BIOS is stored in one flash ROM, and the BIOS is stored in accordance with the purpose of use. Can be easily switched. This eliminates the need for new hardware that differs only in BIOS data.

As a third embodiment of the present invention, the number of blocks in the flash ROM 2 is increased to N (N> 4) to store N-1 BIOS data, and the boot of the status register is correspondingly performed. A configuration in which the number of flags is also increased may be adopted. In this embodiment, the system can be started up with N-1 different BIOS settings.

[0036]

As described above, according to the present invention,
Even if rewriting of the BIOS fails, the system can be reliably prevented from starting when the system is started next time.

The reason is that, in the present invention, a flash ROM is provided with a block in which a plurality of BIOS data are stored, and the BIOS is rewritten to a block different from the block where the system was started. That's because.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration of an address / boot conversion control unit according to an embodiment of the present invention.

FIG. 3 is a flowchart illustrating a processing flow according to an embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of an address / boot conversion control unit 1 according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Address address / boot conversion control unit 2 Flash ROM 3 Flag switch 10 Status (Read / Write) unit 11 Address conversion unit 12 Status (Status) register 120 Boot (Boot) flag 121 Update flag 20, 21, 22 block

Claims (7)

[Claims] A rewritable nonvolatile semiconductor memory device stores a plurality of areas each storing a BIOS and status information including information for determining an area to be read at system startup, and is read first at system startup. When the system is started, first, an area for reading the BIOS is selected based on the information read from the area for storing the status information, the BIOS is read from the selected area, the system is started, and the BIOS is rewritten. Sometimes, of the plurality of areas storing the BIOS, an area different from the area used for system startup is rewritten with a new BIOS, and the next system is rewritten only when rewriting is normally performed with the new BIOS. At startup, the BIOS is read from the newly rewritten BIOS area and the system is read out. Perform the launch, BIOS rewriting method, characterized in that. 2. A flash ROM is divided into a block for storing status information which is read first when the system is started and a plurality of blocks for storing the BIOS, and the flash ROM is read from the block for storing status information when the system is started. From the data, a block from which the BIOS is read is selected, the BIOS is read from the selected block, and the system is started. At the time of BIOS rewriting, a different block from the block used for starting the system (referred to as an “original block”) The block is rewritten with the new BIOS. If the new BIOS is rewritten normally, the contents of the block storing the status information are updated, and the next time the system starts up, the BIOS is rewritten normally. In this case, the newly rewritten BIOS A BIOS rewriting method, comprising: reading a BIOS to start up the system; and, if the rewriting of the BIOS fails, reading out the BIOS from the original block and starting up the system. 3. A rewritable nonvolatile semiconductor memory device, comprising:
The first and second areas storing the IOS and the third area storing status information which is first read out at the time of system startup are divided into the first area and the second area. The status information stored in the third area is read to control the address, the BIOS data written to either the first area or the second area is read, the system is started, and at the time of rewriting the BIOS, Controlling that a new BIOS is written in an area of the first and second areas in the nonvolatile semiconductor memory device that is different from an area used for starting up a system; Address / boot translation for updating the third area with the latest status information regarding which one of the first and second areas is used to start up the system A BIOS rewriting method, comprising a control unit. 4. A boot flag indicating which one of the first and second areas reads the BIOS stored in the address / boot conversion control means to start up the system, and a BIOS rewrite. Status information storage means including an update flag indicating a mode; and when starting up the system, first, status information is read from the third area in the nonvolatile semiconductor memory device, and the contents are stored in the status information storage. Means for inverting the value of the boot flag and writing the value of the status information storage means as new status information in the third area after the end of the BIOS rewrite, and when the update flag is not in the rewrite mode. Is
According to the value of the boot flag, an address is converted so as to access either the first or second area,
When the value of the update flag indicates the rewrite mode, the address is converted so as to access an area of the first and second areas opposite to the area used for reading the BIOS when the system is started. 4. The BIOS rewriting method according to claim 3, further comprising: means. 5. The device according to claim 3, wherein means for switching and setting the value of the boot flag to a fixed value is provided outside the address / boot conversion control means.
IOS rewriting method. 6. A rewritable nonvolatile semiconductor memory device, comprising:
The nonvolatile semiconductor memory device is divided into N (where N is an integer of 3 or more) areas for storing an IOS and N + 1 areas for storing the status information which is first read out at system startup. The address is controlled based on the status information stored in the (N + 1) th area in the area, and the B written in any of the first to Nth areas is controlled.
When the BIOS is read and the system is started, and when the BIOS is rewritten, the first to N-th areas in the nonvolatile semiconductor memory device are different from the area used for starting the system. New BI
Address / boot conversion control means for controlling the writing of the OS to be performed, and for updating the (N + 1) th area to the latest status as to which of the first to Nth areas the system should be started from; A BIOS rewriting method, characterized in that: 7. The rewritable nonvolatile semiconductor memory device according to claim 3, wherein said rewritable nonvolatile semiconductor memory device comprises a flash ROM capable of electrically erasing and writing data on a block basis.
The BIOS rewriting method according to any one of the above.