JP2000148467A - Information processor, basic system program rewriting method of information processor, and recording medium recorded with basic system program rewriting program of information processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information processor capable of rewriting its BIOS program easily without confusing the user by preventing the processor from being disabled to start owing to a failure in the rewriting of the BIOS. SOLUTION: A BIOS ROM 2 is >=2 times as large as the BIOS program size, the BIOS program is held in two divided areas A and B of the BIOS ROM 2 respectively, and the system side is enabled to access only a half area of the BIOS ROM. Further, an address switching circuit 1 is provided between the BIOS ROM 2 and the address bus of the system so that both the area can selectively be accessed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information processing apparatus such as a personal computer, and more particularly to a basic system for testing and initializing various devices at the time of startup, and performing power management and the like after startup. The present invention relates to an information processing apparatus having a rewritable nonvolatile memory (ROM) containing a program (BIOS).

[0002]

2. Description of the Related Art Generally, an information processing apparatus such as a personal computer generally has a CPU (Central Process).
ssing Unit), RAM (Random Ac)
cess Memory), ROM (Read Onl)
y Memory), a hard disk, a chip set, and the like. Of these, ROM is usually an initialization code of each device immediately after the power is turned on, a system setting program, a power saving function, an OS (Operating Sys).
tem) and other functions unique to the system. These codes are transferred to BIOS (Basic I / O
A ROM incorporating a BIOS program is referred to as a BIOS ROM.

Conventionally, this BIOS ROM is an EPROM.
(Erasable P ROM), OTROM (On
e Time ROM) and BIOS RO
In order to change the contents of M, EPROM
Take out the OM and rewrite it, or in the case of OTROM,
There was no other way but to write and replace the contents of the BIOS ROM in a new OTROM.

[0004] In recent years, Flash ROM has been added to the BIOS ROM.
The use of ROMs is increasing, and this allows the BIOS ROM to be removed from the system without being removed.
It has become possible to rewrite by software.

However, during rewriting of the BIOS ROM,
When the power is turned off, for example, due to a power outage, accidentally turning off the power, or running out of battery in a portable information processing device, the rewriting operation ends without being normally written to the BIOS ROM. Due to the nature of the BIOSROM, if such a situation occurs, the system may not be able to start up again, which is a very serious problem. In particular, BIOS
If the ROM is mounted directly on the board without using a socket when mounting the ROM on the system, it is necessary to remove the BIOS ROM from the board. Because of these problems, BI
Making the user rewrite the OS ROM is dangerous.

To solve such a problem, Japanese Patent Laid-Open Publication No.
76 "BIOS rewrite control circuit"
The contents of the ROM are divided into a basic part necessary only for booting and an extended part of a part including other functions.
The inside of the ROM was divided into halves, and a basic part and an extended part were put in each area. In addition, BIO
An address switching circuit capable of exchanging the address indicating the upper half area of the SROM and the lower half address is implemented. (See FIG. 12.) Then, BIOS
When rewriting the contents of the ROM, the basic portion stored in the upper address is usually kept as it is, and the basic portion of the new BIOSROM is written in the extended portion at the lower address. After the writing is completed normally, a new extension is written in the upper part, and then the upper address and the lower address are exchanged by the address switching circuit. By operating in this manner, the address switching circuit is operated because the basic part of the old BIOS before rewriting or the new BIOS after rewriting is always stored in either the upper or lower address regardless of the power supply.
Since the system can be started from any part, the situation that the system cannot be started does not occur. Even if the rewriting does not end normally, the new or old BIO
Since the S basic part remains, it can be started up in either basic part, and the BIOS can be rewritten again.

[0007]

However, in the above-mentioned Japanese Patent Application Laid-Open No. 8-69376, it is necessary to divide the ROM area into two parts and to create a BIOS ROM divided into a basic part and an extended part. Moreover, in principle, it is necessary to make the basic portion and the extension portion the same size. However, the functions of personal computers in recent years have been remarkably expanded, and the code size of both the initialization at the time of startup and the extended functions during the startup has been increasing. In this situation, when designing and developing the BIOS program, the BIOS
Creating an S program is a very difficult task,
There was a problem that the development efficiency was significantly reduced.

Japanese Patent Laid-Open No. 8-69376 discloses a BIOS.
The user must manually switch the ROM address. Further, if the system does not start after rewriting the BIOS, the user cannot determine whether the rewriting has failed or other settings are wrong, which may only result in confusion for the user. Also, if the BIOS itself can write normally and the settings are incorrect, if the user switches the BIOS address, the system will try to boot from the extended part of the BIOS, and cannot boot normally. That is, even when switching addresses, it is impossible to determine which of the BIOS ROM is the area to be booted or whether there is simply a problem with the setting, so that there is a problem that a beginner user cannot practically rewrite the BIOS. there were.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to eliminate the necessity of separately considering a basic part and an extended part when designing and developing a BIOS program. It is assumed that. That is, BIO
In an S program, dividing a program into a basic part and an extended part means that the original system startup processing,
This is a separate problem from processing such as setting processing of various devices, power management during operation, provision of other functions, and the like. It aims to eliminate problems. In other words, the purpose is to divide the BIOSROM into a plurality of parts, and to set each area to a size that allows the BIOS program to be stored as it is, so that it is not necessary to consider only the BIOS rewrite such as program division. .

Further, it is possible to prevent the user from being confused when the rewriting of the BIOS fails, and to prevent the user from changing the BIOS.
An object of the present invention is to provide an information processing apparatus that can easily rewrite the BIOS without any worries even for a beginner unfamiliar with a computer by eliminating the need to switch the ROM.

It is another object of the present invention to provide an information processing apparatus which is easy for all users to use by notifying the user whether the rewriting of the BIOS program has been completed or has failed.

[0012]

In order to solve the above-mentioned problems, the present invention provides a plurality of rewritable basic system program storage means each having the same address storing a basic system program, and the rewritable basic system. Selecting means for selecting any one of the program storage means, and activating based on the basic system program stored in the rewritable basic system program storage means selected by the selection means at startup. It is an information processing apparatus characterized by the following.

Further, the present invention is characterized in that it comprises a basic system program rewriting means for rewriting a basic system program for the rewritable basic system program storage means selected by the selection means among the plurality of rewritable basic system program storage means. This is an information processing device.

Further, the present invention provides a determining means for determining whether or not the basic system program stored in the rewritable basic system program storage means selected by the selecting means at the time of startup is normal, and the basic system program being determined by the determining means. An information processing apparatus comprising: a switching unit that switches a rewritable basic system program storage unit when it is determined that is not normal.

Still further, according to the present invention, when the determining means determines that the basic system program stored in the rewritable basic system program storage means selected by the selecting means is not normal, an alarm for notifying the abnormality of the basic system program is provided. An information processing apparatus comprising means.

Further, the present invention is an information processing apparatus comprising a copying means for copying a basic system program stored in a rewritable basic system program storage means to another rewritable basic system program storage means.

That is, according to the present invention, the BIOS ROM needs to include two complete BIOS programs in a general computer configuration.
The size of the BIOS ROM is twice or more the size of the BIOS program, and the system ROM is made to be able to access only the half area of the BIOS ROM from the system ROM. BIOS to be selectively accessible
An address switching circuit is provided between the ROM and the address bus of the system.

Further, when rewriting the BIOS program in the BIOS ROM, the BIOS ROM area currently used for starting is kept as it is, and another BIOS
By rewriting the SROM area, even if the power is turned off during the rewriting operation and the BIOS cannot write normally, the address switching circuit described above is operated to enable the BIOS ROM area on the non-rewritten side. Can be activated.

Further, when the BIOS is started, a process such as calculating a checksum of the BIOS program is performed to confirm whether or not the BIOS program to be started is normal. If the system is normal, the system is started normally. If it is determined that the system is not normal, the normal BIOS ROM is enabled and the system is started.

Further, a display element such as an LED for displaying a state as to whether or not the BIOS ROM has been normally rewritten is attached to the system, or an alarm sound generating element is attached to the system.

Furthermore, in the boot process immediately after rewriting the BIOS ROM, if it is determined that the BIOS program is normal, a function of copying the rewritten normal BIOS program to the unrewritten BIOS ROM area is provided.

According to the above configuration, the BIOS R is divided into two parts so that two BIOS programs can be stored.
The system (CP) is controlled by the OM and the address switching circuit.
When the BIOS ROM is accessed from U), only the BIOS ROM on one side becomes accessible, and when the switching circuit is operated, only the BIOS ROM on the other side becomes accessible. There may be a BIOS program that is saved at the time of BIOS update without being involved in the update.

Even if the BIOS rewriting fails, the BIOS program before rewriting always exists, so that
The operation of the address switching circuit guarantees the activation of the system. Therefore, it is possible to rewrite the BIOS again. The operation of the address switching circuit can be performed by a user,
It is also possible to configure so that the CPU automatically performs the processing.

Since it is possible to automatically determine whether the rewriting of the BIOS has succeeded or failed, even if the rewriting of the BIOS has failed, the system can be started in the BIOS before the rewriting without operating the address switching circuit.

Whether or not the BIOS has been rewritten normally can be easily confirmed by using an LED or an alarm sound.

When the BIOS is rewritten, two BIOS
The contents of the OS ROM area always become the same latest BIOS program. Copying to another area is performed after confirming that BIOS rewriting has been performed normally, so that copying can be performed safely.

[0027]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing a configuration of an information processing device such as a personal computer according to an embodiment of the present invention. In addition to the configuration of a conventional general computer, an address switching circuit 1 and a BIO divided into two areas
It has an SROM2. The respective areas of the BIOS ROM are defined as BIOS ROMA and BIOS ROA.
Called MB. In other words, even if there is one physical ROM,
Divide each area into BIOS ROMA, BIO
It is distinguished from S ROMB. In recent years, as a ROM used as a BIOS ROM of a personal computer, a flash ROM whose contents can be rewritten without being removed from a board by software is often used. Also, these flash ROMs are 8Kbytes
Many can be rewritten in units or 16 Kbytes. The present invention can be realized by such a flash ROM that can be rewritten in a certain area unit.

The address switching circuit 1 shown in FIG. 1 operates in the BIOS address space of the BIOS ROMA or the BIOS ROMB in the address space of the system.
Switch so that an area is allocated. One embodiment of the switching circuit 1 will be described in detail.

FIG. 2 is a diagram showing details of the address switching circuit. Now the code size of BIOS is 256Kby
Let te. Of course, even when the code size of the BIOS is 128 Kbytes or 512 Kbytes, it can be realized in the same manner as described below only by increasing or decreasing the number of address lines. BIOS ROM2 is 2
It is necessary to have a capacity of 512 kbytes having a capacity enough to accommodate two 56 Kbytes of BIOS. Also, it is necessary that the data can be rewritten for each 256 Kbyte area. A flash ROM that can be rewritten by dividing the inside of a normal ROM is 8 Kbytes as described above.
e, 16Kbytes, so 256
Rewriting can be performed in Kbyte units. 25
Since the total capacity is 512 Kbytes for each 6 Kbytes, the address lines are 19 A0 to A18 shown in FIG.
The entire area of the IOS ROM 2 can be accessed. On the other hand, the system body is connected to A0 to A17. Therefore, from the system body side, 256
The Kbyte area becomes accessible. A18 is not connected to the address line of the system, and is 0 (Low) or 1 (High) by the changeover switch SW3.
To be fixed to Therefore, BIOS ROM2
Selects whether the upper 256 Kbytes or the lower 256 Kbytes is accessed depending on the value of SW3. That is, when SW3 is set to 0, the BIOS
Since the most significant bit of the 19-bit address line in the ROM 2 is always 0, the address space of 256 Kbytes accessed from the system is 512 Kbytes.
Address space in the BIOS ROM 2 (0 to 7F)
FFFh), the lower 256 bytes of address space (0 to 3FFFFh) are allocated, and SW3
Is set to 1, on the contrary, since the most significant bit of the 19-bit address line of the BIOS ROM 2 is always 1, the 256 KByte address space accessed from the system is the address space of the BIOS ROM 2 (0 to 7FFF).
Fh), the upper 256 bytes of the address space (4
000h to 7FFFFh) (see FIG. 3).

For example, an address represented by A17 to A0 becomes 3A3A3h by an access from the system.
If A18 is 0, 03A3A3h in the address space (0 to 7FFFFh) in the BIOS ROM2
When A18 is 1, 7A3A3h is accessed in the same address space. In this way, the simple operation of operating the address line A18 by SW3 allows the BIOS to operate without being aware of the system.
Switching between ROMA and B can be performed.

Next, a procedure for rewriting the BIOS program will be described with reference to FIG. Since the BIOS program is rewritten, BIOS ROMA, BIOS RO
It is assumed that a BIOS program that normally starts is written in at least one of the MB areas. Now, a normal BIOS is written in the BIOS ROMA, and the system is in a state of being activated. A method of rewriting (upgrading) the BIOS of the system will be described.

First, the general flow will be described. When the system is first turned on (S41), the BIOS ROMA
To start the system (S42). Next, BIOS RO
The MB area is made accessible, and a new BIOS is written to the BIOS ROMB area (S43). At this time B
The IOS ROMA remains. BIOSRO
Since the MB area is in an accessible state, when the system is restarted thereafter, it starts up from the BIOS ROMB area (S44). If the system power is turned off due to an accident during the writing of a new BIOS into the BIOS ROMB area and the BIOS ROMB area cannot be written normally, there is a high possibility that the system cannot be started from the BIOS ROMB area. . In that case, if the address is switched by the address switching circuit and the operation is started from the area of the BIOS ROMA, it can be assured that the operation is normally started.

Starting from the BIOS ROMA, the same procedure is repeated again and again until the rewriting succeeds,
The area of the OS ROMB can be rewritten, and the system cannot be started.

FIG. 3 shows the BIO used in the present invention.
6 is a memory map including SROM2. In FIG. 3, the left part is a very common IBM PC /
This is basically the same as the memory map of a personal computer called an AT compatible machine. However, the BIOS ROM 2 of 256 Kbytes is mapped at the highest address. Other parts are used as RAM and ROM of other expansion boards. The upper right part of the figure is BIO
This is an address map inside the SROM 2. BI
The upper address portion or the lower address portion of the OS ROM 2 is selectively mapped to the BIOS ROM area of the main unit. The BIOS ROM rewriting procedure will be described in a little more detail with reference to this memory map and a diagram illustrating the BIOS rewriting procedure in FIG.

First, the system is turned on (S5).
1). Since the BIOS ROMA is selected by the SW3, the system is started from the BIOS ROMA.
SW3 is set to 0 because it is running from BIOSROMA.
(Low). In this state, B
IOS ROM area (FFFFFFFFh to FFFC0
000h) will access the BIOS ROMA area (0h to 3FFFFh) in the BIOS ROM2. Since a new BIOS is written to the BIOS ROMB to upgrade the BIOS, SW3 is switched to 1 (High) (S53).
Immediately after this switching, access to the BIOS ROM area is converted to access to the BIOS ROMB area (40000h to 7FFFFh) in the BIOS ROM. B when BIOS ROMB is selected
The BIOS rewriting software is activated to rewrite the BIOS (S54). Finally, after rewriting, the system is restarted (S55). If the rewriting is normally completed at the time of rewriting in S54, since the SW3 is set to 1 at the time of restarting, the system starts up from the rewritten area of the new BIOS ROMB (S56). In S54, B
As described above, when the BIOS ROMB is not normally rewritten due to an accident such as a power failure of the system while rewriting the area of the BIOS ROMA, no access is made to the area of the BIOS ROMA when the BIOS is rewritten. Therefore, the BIOS before rewriting remains. BIO likely to be broken
By setting SW3 to 1 instead of S ROMB, the system can be started normally when a normal BIOS ROMA is selected and the system is started. After normal startup, the BIOS ROMB may be rewritten according to the procedure of FIG. 5 again. That is, even if rewriting fails, the above procedure can be repeated and executed until it succeeds. In no case will the system fail to boot.

The BIOS program normally calculates a checksum of the entire program at an early stage of the startup process in order to determine whether or not the BIOS program itself is normal. In general, the boot is continued only when the result is correct, and when the result is not correct, the boot is generally interrupted. This checksum is calculated by BIO
This can be used to determine whether or not S writing has been performed normally.

Here, the switch SW3 is not a physical switch such as a jumper switch but can be controlled by software in correspondence with an I / O port or the like, so that the state of the switch is changed from the CPU through the bus. Will be able to When the checksum is calculated at the beginning of the BIOS program and it is determined that the booting BIOS is an invalid BIOS, by switching SW3 to the other, even if the BIOS rewriting fails, the other normal is automatically performed. It can be started from any BIOS. This procedure will be described with reference to FIG.

After power ON (S61), if SW3 is 0, B
The control is transferred to the boot processing program of the BIOS program in the IOS ROMA.
The control is transferred to the boot processing program of the BIOS program in the MB (S62). In the BIOS program, the control is transferred to the BIOS program after the power is turned on, and the checksum of the ROM is calculated immediately after the start-up process is started (S63).
If it is confirmed that the checksum is normal as a result of the calculation, the startup processing is continued without any problem (S64).
If it is determined that the checksum is abnormal, the BI
It is determined that the OS program has not been correctly written. After that, the boot process cannot be continued with the BIOS that has not been written normally. In this case, the BIOS program switches SW3 to 1 if it is currently 0 and to 0 if it is currently 1 (S65). After that, the system is reset and restarted (S66), and the process returns to S62.
Since SW3 has been switched, this time the BIOS written in the BIOS ROM area before rewriting that has been written normally
An initialization process is executed by the OS program. Naturally, the checksum calculation becomes normal, and the BIOS continues the boot process, and the system boots normally (S64).

The other BIOS ROM area is normally
Since the OS program has not been written, the rewriting process may be performed again. As described above, even if rewriting fails, the system automatically starts up from the normal BIOS ROM area as many times as possible. However, in this state, since the apparatus is normally started, the user cannot determine whether the rewriting of the BIOS ROM has been completed normally as desired. In order to avoid this, as shown in FIGS. 7 to 9, an LED display is used to warn of failure of rewriting of the BIOS ROM, or a method of sounding an alarm is used to prompt the user to rewrite. be able to.

FIG. 7 is a block diagram showing the case where the status is displayed by the LED, and FIG. 8 is a block diagram showing the case where the alarm sound is generated. This is obtained by adding a status display LED 4 for displaying a rewrite status or an alarm sound generating device 5 for warning rewrite failure to the device shown in FIG.

FIG. 9 is a diagram for explaining the flow of processing in these cases. After the power is turned on (S91), SW3 becomes 0
If so, the control is transferred to the boot processing program of the BIOS program in the BIOS ROMA.
The control is shifted to the boot processing program of the BIOS program in the ROMB (S92). In the BIOS program, the control is transferred to the BIOS program after the power is turned on, and the checksum of the ROM is calculated immediately after the start-up processing is started (S9).
3). If it is confirmed that the checksum is normal as a result of the calculation, the startup processing is continued without any problem (S9).
4). If it is determined that the checksum is abnormal, it is determined that the BIOS program has not been correctly written. After that, the boot process cannot be continued with the BIOS that has not been written normally. In this case, the BIOS
The program switches SW3 to 1 if it is currently 0 and to 0 if it is currently 1 (S95). Next, in order to indicate that the BIOS is abnormal, the status display LED 4 is turned on or the alarm sound generator 5 generates an alarm sound (S9).
6). After that, the system is reset and restarted (S97), and the process returns to S92. Since the switch SW3 has been switched, the initialization process is executed by the BIOS program in the BIOS ROM area before the rewriting which has been normally written this time. Naturally, the checksum calculation becomes normal, and the BIOS continues the boot process and the system boots normally (S94).

Here, when the LED is turned on or an alarm sound is generated after the system is started, it indicates that the BIOS program has not been normally written in one area of the BIOS ROM. That is, if the LED is lit or an alarm sound is generated in the normal startup state, if the switch SW3 is 0 at that time, the BIOSRO
MB is BIOS ROMA if SW3 is 1
Means that the value of the checksum is invalid, and the BIOS program has not been correctly written. Based on this,
What is necessary is just to rewrite the unauthorized BIOS ROM again.

The apparatus shown in FIG. 10 is provided with a status display LED 4 and a BIOS rewrite flag 6 for retaining information that the BIOS program has been rewritten in the information processing apparatus shown in FIG. Of course, it is also possible to equip with an alarm sound generating device and others in place of the status display LED. Generally, a personal computer or the like has a non-volatile memory such as a CMOS RAM which is backed up by a battery or the like so as to be constantly turned on to store various setting information. The BIOS rewrite flag 6 can be realized by a part of such a nonvolatile memory.

The BIOS rewriting process in this configuration will be described with reference to FIG. First, the main body power is turned on (S111). When SW3 is 0, the BIOS ROM
From A, in the case of 1, the system is started from the BIOS ROMB (S112). SW3 is switched to the BIOS ROM area not used for activation for rewriting.
If SW3 is 0, it is changed to 1; if it is 1, it is changed to 0 (S113). Write a new BIOS program to the switched BIOS ROM area (S11
4). After the rewrite is completed, the BIOS rewrite program sets the BIOS rewrite flag 6 to indicate that the rewrite has been performed (S115). Since the BIOS ROM has been rewritten, the system is restarted (S116). Booting starts from the rewritten BIOS ROM (S117). Next, a checksum is calculated in the initial stage of the boot process, and it is determined whether the rewritten BIOS is normal (S118).

The BIOS rewriting process (S114)
If the data is not correctly rewritten due to any reason such as power-off, the checksum calculation (S118) uses BIO
It is determined that S is not normal. If the rewriting has not been performed normally, the rewriting is not completed, so that the BIOS rewriting flag 6 after the rewriting (S114) is not set and the flag is reset. If the BIOS determines that the BIOS is not normal,
SW3 is inverted (S119), the status display LED 4 is turned on (S1110), and the system is restarted (S111).
1), the boot process is started on the old BIOS ROM side before rewriting (S117). Since the subsequent calculation of the checksum (S118) becomes normal, normal startup processing is performed (S1112). Since the BIOS rewrite flag 6 has been cleared as described above, as a result of confirmation (S1113), normal OS loading is performed (S1114). After the normal startup in this manner, the user turns on the BIO by lighting the status display LED.
Since it is known that rewriting of S failed, the BIOS
The ROM may be rewritten.

On the other hand, if it is determined in the calculation of the checksum immediately after rewriting the BIOS (S118) that the BIOS has been written normally, the other BIOS RO in which the old BIOS program is still written remains
The operation of copying a new BIOS program to the area M starts. However, the copying operation is not immediately started, but a normal series of startup processing is performed first (S111).
2). Because, as described above, the checksum calculation is at the very beginning of the start-up process, and at this point, devices such as RAM required for the copy operation have not been initialized. Therefore, copying the BIOS ROM requires the BIOS
Perform at the end of the entire startup process. The BIOS rewrite flag 6 is checked at the time when the normal startup processing is completed (S111).
3).

If the BIOS rewrite flag 6 is not set, the BIOS is not rewritten at the time of the immediately preceding booting, and the booting is performed during normal use.
The boot process of the OS program ends, the boot process of the OS stored in the hard disk or the like is started, and the process is passed to the OS (S1114).

When the BIOS rewrite flag 6 is set, the BIOS is rewritten immediately before the activation, and
The BIOS program stored in the BIOS ROM area on the opposite side of the BIOS ROM currently designated for startup indicates the old BIOS before rewriting. In this case, copying of the BIOS program between the two BIOS ROM areas is started. First, the contents of the currently activated BIOS ROM area are initialized to R
Copy to AM (S1115). Usually, RAM has a capacity of at least several megabytes, and at most several hundred megabytes, so that there is enough capacity for copying. Next, in order to perform writing, SW3 is inverted so that the old BIOS can access (S1116). That is, the current SW3 is 0
If you have booted from BIOS ROMA, change SW3 to 1 and BIOS RO which should contain the old BIOS
The MB is made accessible, and if SW3 is 1, SW3 is set to 0 to make the BIOS ROMA accessible. The BIOS writing program built in the BIOS ROM is started, and the new BIOS program copied on the RAM is written in an appropriate BIOS ROM area (S1117).

When the writing is completed normally, the BIOS rewriting flag 6 is cleared after rewriting (S111).
8). At this point, BIOS ROMA, BIOS RO
Both MBs have been rewritten with the new BIOS program. Since the BIOS ROM has been rewritten, the system is restarted (S1119). Since it is a normal startup, S117,
The processing proceeds in the order of S118, S1112, S1113, and S1114, and the OS starts normally.

In the event that an accident such as the power being turned off during rewriting occurs in S1115, the next startup (S1115)
7) The BIOS boot process is performed, but SW3 is set to the normal BIOS ROM because the power is turned off during S1115. Therefore, the checksum calculation is OK, the boot process is performed (S1112), and the BIOS rewrite flag 6 is confirmed (S1113). When the power is turned off during the BIOS rewriting in S1115, the BIOS
Since the rewrite flag 6 is still set, copying of the BIOS ROM is started again (S111).
5, S1116, S1117). If the operation is normally performed, the BIOS rewrite flag 6 is cleared (S1118) and restarted (S1119) in the same manner as described above, and the system is normally started. If a problem occurs during rewriting again,
The above procedure is repeated, and finally the data is rewritten normally.

On the other hand, if an accident such as the power being turned off during rewriting occurs in S1117 instead of S1115,
Next, when the system is activated (S117), the BIOS activation process is performed, but the checksum calculation results in NG, the SW3 is switched (S119), and the system is restarted (S111).
1). The BIOS boot process (S117) is performed again. The BIOS at this time is a new BIOS ROM that has been rewritten first.
It will be started from. BIO written correctly
Since it is S, it becomes normal this time in the checksum calculation (S118), and a startup process is performed (S1112), and the BIOS
Check the rewrite flag 6. Since the power supply is turned off during the previous BIOS rewriting, the BIOS rewriting flag 6 is still set, so the BIOS ROM
Start copying (S1115, S1116, S111
7). If successful, follow the steps described above,
Clearing the rewrite flag 6 (S1118), restarting (S1)
119) and start up normally. If a problem occurs during rewriting again, the above procedure is repeated, and finally, the rewriting is normally performed. By the above procedure, no matter where the power is turned off during the BIOS rewriting,
Both IOS ROMA and BIOS ROMB are new BI
The OS program is normally written.

The basic system program rewriting method as described above is mainly composed of a BI system other than that used at the time of startup.
A step of selecting an OS ROM by an address switching circuit, a step of rewriting the BIOS of the selected BIOS ROM, and a step of rewriting the BIOS of the rewritten BIOS ROM.
A floppy (registered trademark) disk as a basic system program rewriting program including a step of restarting the system using the IOS and a step of rewriting the BIOS by selecting an BIOS ROM other than the one used at the time of the restart by the address switching circuit. And CDR
It can be recorded and supplied to OM or the like.

[0053]

As described above, according to the present invention,
When rewriting a BIOS program, the BIOS program before rewriting exists in the system at any stage of the rewriting. For this reason, even if rewriting of the BIOS program fails due to power supply cutoff or the like, it is always possible to start up with the complete BIOS before rewriting. The BIOS can be normally used as it is before rewriting, and the BIOS can be rewritten many times.

When the BIOS rewrite fails,
B before rewriting without operating the address switching circuit
Operability can be improved because it can be started by the IOS. Even if the rewriting fails, the user can execute the BIOS rewriting again in the system that has been automatically started.

Further, whether or not the BIOS rewriting has failed can be easily confirmed by using an LED or the like. Even if the system has not been carefully monitored whether or not the rewriting was successful at the time of rewriting the BIOS, it can be easily understood whether or not the BIOS was rewritten normally when the system was restarted after the BIOS rewriting operation.

Further, whether or not the BIOS rewriting has failed can be easily confirmed by an alarm sound or the like. Even if the system is not carefully monitored whether or not the rewriting has succeeded normally at the time of rewriting the BIOS, it can be easily determined whether or not the BIOS rewriting has been normally performed when the system is restarted after the BIOS rewriting operation.

Further, since the same BIOS program always enters the two ROM areas after the successful BIOS rewriting, there is no need to worry about the versions of the BIOS programs in the two ROM areas. There is no problem if the setting of the address switching circuit is reversed in the event that some trouble occurs in the system. In other words, two B
There is no need to be aware of the IOS ROM area, and it is possible for the user to treat it as a normal BIOS ROM that can be rewritten even if the BIOS rewrite fails.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of an information processing device according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating details of an address switching circuit of the present invention.

FIG. 3 is a memory map of a BIOS ROM used in the present invention.

FIG. 4 is a diagram illustrating a BIOS program rewriting procedure according to the present invention.

FIG. 5 is a diagram for explaining a BIOS program rewriting procedure of the present invention.

FIG. 6 is a diagram illustrating a BIOS program rewriting procedure according to the present invention.

FIG. 7 is a diagram illustrating a configuration of an information processing device according to another embodiment of the present invention.

FIG. 8 is a diagram showing a configuration of an information processing device according to still another embodiment of the present invention.

FIG. 9 is a diagram illustrating a BIOS program rewriting procedure according to the present invention.

FIG. 10 is a diagram showing a configuration of an information processing device according to another embodiment of the present invention.

FIG. 11 is a diagram for explaining another BIOS program rewriting procedure of the present invention.

FIG. 12 is a diagram illustrating a configuration of a conventional information processing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Address switching circuit 2 BIOS ROM 3 Address switching switch 4 Status display LED 5 Alarm sound generator 6 BIOS rewrite flag

Claims (7)

[Claims] 1. A plurality of rewritable basic system program storage means each having the same address storing a basic system program, and a selection means for selecting one of the rewritable basic system program storage means. An information processing apparatus, comprising: starting up based on a basic system program stored in a rewritable basic system program storage unit selected by the selection unit at the time of startup. 2. A rewritable basic system program storage means selected from among the plurality of rewritable basic system program storage means and a basic system program rewriting means for rewriting a basic system program for the rewritable basic system program storage means. Item 10. The information processing apparatus according to Item 1. 3. A deciding means for judging whether or not the basic system program stored in the rewritable basic system program storing means selected by the selecting means at the time of starting is normal, and the basic system program is not normal by the judging means. 3. The information processing apparatus according to claim 1, further comprising a switching unit configured to switch a rewritable basic system program storage unit when the determination is made. 4. An alarm means for notifying the abnormality of the basic system program when the judgment means judges that the basic system program stored in the rewritable basic system program storage means selected by the selection means is not normal. 4. The information processing apparatus according to claim 3, wherein: 5. A rewritable basic system program storing means for copying a basic system program stored in a rewritable basic system program storing means to another rewritable basic system program storing means. The information processing device according to claim 3 or claim 4. 6. A plurality of rewritable basic system program storage means each having the same address in which a basic system program is stored, and a selection means for selecting any one of the rewritable basic system program storage means. A method of rewriting a basic system program for an information processing apparatus comprising: a rewritable basic system program storage unit other than the rewritable basic system program storage unit used at the time of startup by the selection unit; And restarting the system using the rewritten basic system program of the rewritten rewritable basic system program storage means, and selecting a rewritable basic system program storage means other than the one used at the time of the start by the selection means, Write a program Basic system program rewriting method of an information processing apparatus characterized by obtaining. 7. A plurality of rewritable basic system program storage means each having the same address storing a basic system program, and a selection means for selecting any one of the rewritable basic system program storage means. Selecting a rewritable basic system program storage unit other than the one used at the time of startup by the selection unit, and a basic operation of the selected rewritable basic system program storage unit. Rewriting the system program, restarting the system using the rewritten basic system program of the rewritten basic system program storage means, and selecting the rewritable basic system program storage means other than the one used at the start. To Recording medium recording the basic system program rewriting program of the information processing apparatus, characterized in that it comprises the step of rewriting the basic system program and select I.