JP2004094820A - Electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the occurrence of troubles due to updating when updating a program. <P>SOLUTION: A start processing program group and a functioning program group are recorded in a ROM 2 in the order of the starting processing program group and the functioning program group. The functioning program group is a program group for achieving various functions of an electronic device, while the start processing program group includes an initializing program for initializing the electronic device, a starting program for processing the start of the functioning program and an updating program for updating the functioning program group in the ROM 2, which are recorded in the ROM 2 in the order of the initializing program, the starting program and the updating program. The updating program updates the functioning program group in the ROM 2. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a technology for updating a program such as a firmware program incorporated in various electronic devices for version upgrade, and more particularly to a technology for suppressing occurrence of a failure due to the update.
[0002]
[Prior art]
For example, various electronic devices often have a function of updating a firmware program incorporated in a form stored in a rewritable nonvolatile memory such as a ROM in a timely manner in order to upgrade the firmware.
Conventionally, such a firmware program has been updated simply by rewriting the firmware program on the ROM with a new firmware program.
[0003]
[Problems to be solved by the invention]
According to the conventional firmware program update technology, if a failure such as power-off occurs during the update work, the firmware program in the ROM is rewritten in an incomplete form. Since the electronic device cannot be executed normally, the electronic device may not be able to be started normally, or the firmware program may not be updated again.
[0004]
Therefore, an object of the present invention is to provide a self-update program that suppresses the occurrence of a failure due to the update when the program is updated.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides an electronic device that performs a function by executing a program, and causes the electronic device to perform the function on a rewritable nonvolatile memory storing the program. A first program group, a start processing program that initializes the electronic device and starts the programs of the first program group, and an update program that updates the program of the first program group with a new program. And the second program group is divided and stored so that each program group can be independently rewritten, and the update program is updated by updating the program of the first program group to a new program. This is a program to be executed by the device.
[0006]
As described above, the first program group and the second program group are divided and recorded, and the first program group is updated. Therefore, when a failure occurs during the update processing of the first program group, it is difficult to execute the update. However, the failure does not damage the second program group.
[0007]
Therefore, even if a failure occurs due to the update processing, the function of each program belonging to the second program group can be used by restarting, so that, for example, the update processing program belonging to the second program group Can be used to update the program again.
In such an electronic device, the update program is verified by checking the normality of the update of the program of the first program group. If the verification of the normality fails, the program of the first program group is updated. The re-updating process may be performed by a program that causes the electronic device to execute the process. By doing so, the program of the first program group can be more reliably updated.
[0008]
Here, the update program is a program that causes the electronic device to execute a process of updating a program of the first program group and a program of the second program group by a rewrite sequence of the nonvolatile memory that is independent of each other. Is also good. As described above, the rewriting sequence of the volatile memory is performed independently for the first program group and the second program group whose capacity is smaller than that of the first program group. The probability that a failure will occur during the update process can be kept low, whereby the operation of the electronic device freezes due to the inoperability of the programs in the second program group after the update process, and the update by the update program cannot be performed again. It is possible to suppress that the operation cannot be performed.
[0009]
In this case, it is preferable that the update program is a program that first updates the activation processing program when updating the program of the second program group. As a result, the probability that a failure occurs in the boot processing program due to the update processing is reduced, and since the boot processing program does not operate after the update processing, the operation of the electronic device freezes and the like. It is possible to prevent a situation in which a measure cannot be taken.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described by taking an example of application to a firmware program update of an electronic device.
FIG. 1 illustrates a configuration example of an electronic device to be updated with a firmware program in the present embodiment.
As shown in the figure, the electronic apparatus includes a CPU 1, a rewritable ROM 2 such as a flash memory, a RAM 3 used as a main memory of the CPU 1, and an external storage medium to which an external storage medium 5 such as a general-purpose memory card can be mounted. An input device 7 such as a key switch connected via an interface 4 and an input interface 6; a display device 9 such as an LCD connected via a display interface 8; a function unit 10 for providing functions of the electronic device; It has an external input / output interface 11 for connecting to a device. The ROM 2 is a rewritable nonvolatile memory capable of erasing and writing data in units of blocks.
[0011]
Here, the electronic device is, for example, a printer. In this case, the function unit 10 provides a printing function, and is connected to a device that is a host of the printer, such as a personal computer or a digital camera, via the external input / output interface 11. become.
[0012]
In the present embodiment, as shown in FIG. 2, the boot processing program group and the function program group are stored in the ROM 2 so that the blocks of the ROM 2 are not shared by the boot processing program group and the function program group. Are recorded in the order of the function program group. Here, the function program group is a group of function programs for realizing various functions of the electronic device. On the other hand, the startup processing program group includes an initialization program for initializing the electronic device, a startup program for performing startup processing of the function program, and an update program for updating the function program group in the ROM 2. These are recorded in the ROM 2 in the order of the initialization program, the startup program, and the update program.
[0013]
Now, in such a configuration of the electronic device, the operator updates the functional program group in the ROM 2 to the external storage medium 5 storing the new functional program group (hereinafter referred to as “updated program” for convenience). The update is performed by attaching to the medium interface 4 and inputting an update instruction through the input device 7.
[0014]
When an update instruction is input, the CPU 1 performs the following update processing by loading the update program into the RAM 3 and executing the update program.
FIG. 3 shows the procedure of the updating process.
As shown in the drawing, in the updating process, first, an updating flag is set (step 302). This updating flag is set in the nonvolatile memory. Although the ROM 2 can be used as the nonvolatile memory, a nonvolatile register may be separately provided.
[0015]
Next, i is set to 0 (step 304), and the St + i-th block in the ROM 2 is erased (step 306). Here, St is the number of the first block in the ROM 2 where the functional program group is recorded.
Then, one block of data is read from the external storage medium 5 from the address advanced by i block size from the beginning of the updated program, and copied to the St + i-th block of the ROM 2 (step 308).
Then, the data stored in the ROM 2 is read, and the consistency with the data previously read from the external storage medium 5 is verified (step 310). Then, it is checked whether the verification has succeeded (step 312). If the verification has failed, the process returns to step 308 to copy the data again. However, if the verification of the same block in the ROM 2 has failed a predetermined number of times or more, a predetermined error process may be performed.
[0016]
On the other hand, if the verification is successful, it is checked whether or not copying to the ROM 2 has been completed up to the last data of the post-update program of the external storage medium 5 (step 314). Clear (step 316) and the process ends.
On the other hand, if the copying to the ROM 2 has not yet been completed up to the last data of the updated program in the storage medium, i is incremented by 1 (step 318), the process returns to step 306, and the next block of the ROM 2 is read. The data of the updated program is copied from the external storage medium 5.
[0017]
Here, according to the above-described arrangement of the programs on the ROM 2 and the update processing, the startup processing program group and the function program group are divided and recorded in the ROM 2, and the function program group is updated. Even if a failure occurs, the startup processing program group will not be damaged by the failure.
[0018]
Therefore, even if a failure occurs due to the update processing, the functions of the programs belonging to the boot processing program group can be used by restarting. For example, the update processing program belonging to the boot processing program group can be used. With this, the program on the ROM 2 can be updated again.
[0019]
By the way, when the above-mentioned update flag is set in the startup program at the time of starting the electronic device, the update processing program is automatically executed, so that the program on the ROM 2 is automatically updated again as described above. Will be able to do.
[0020]
Now, in the case of updating the boot processing program group in the electronic device as described above, as shown in FIG. 2, a boot processing program that updates the boot processing program group by the same processing as the update processing described above. An update program for updating the group may be included in the function program group, and the CPU may execute the program to update the startup processing program group.
[0021]
In this case, as described above, in the boot processing program group, the initialization program and the boot processing program are recorded at the top of the ROM 2, and these are updated first. The probability that the initialization program and the start-up processing program are damaged due to a failure that occurs in the update processing can be reduced, which causes the operation of the electronic device to freeze after the update processing, and to overcome the problem thereafter. It is possible to prevent a situation in which a measure cannot be taken.
[0022]
As described above, according to the present embodiment, when the program update process is being performed, the program written in the program memory is affected by the power off, a defect in the program after the update, the removal of the external storage medium 5, and the like. If a problem occurs, the probability that processing for overcoming the problem can be continued can be increased.
[0023]
By the way, in the update processing shown in FIG. 3 of the above embodiment, by setting St to 0, both the startup processing program group and the function program group can be updated. Even in such a case, the startup processing program group is recorded at the top of the ROM 2 and is updated first, so that the probability that the startup processing program group is damaged by a failure that occurs in the update processing is reduced. As a result, it is possible to prevent a situation in which the operation of the electronic device freezes after the update process, and it becomes impossible to take measures for overcoming the problem thereafter.
[0024]
Alternatively, by configuring the update program to perform the update processing shown in FIG. 4 instead of the update processing shown in FIG. 3, the update program updates both the activation processing program group and the functional program group. May be.
That is, in the updating process, first, an updating flag is set (step 402). Next, the target is set to the startup processing program group (step 304), and the startup processing program group recording block in the ROM 2 is deleted (step 406).
Then, the data of the startup processing program group set as a target is read from the external storage medium 5 and copied to the ROM 2 (step 408).
Then, the data stored in the ROM 2 is read, and the consistency with the data previously read from the external storage medium 5 is verified (step 410). Then, it is checked whether or not the verification has succeeded (step 412). If the verification has failed, the process returns to step 408 to copy the data again.
[0025]
On the other hand, if the verification is successful, it is determined whether the update has been completed (step 414). If completed, the updating flag is cleared (step 416), and the process ends. Here, it is determined that the update has been completed if a functional program group is set as a target at that time.
[0026]
On the other hand, if the update has not been completed yet, the target is set to the functional program group (step 418), and the process returns to step 406 to copy the data of the functional program group set as the target.
Here, according to the above-described arrangement and update processing of each program on the ROM 2, the startup processing program group and the function program group are divided and recorded in the ROM 2, and the erasing-writing for rewriting data in the ROM 2 is performed. The sequence is performed independently for each program group by the activation processing program group and the function program group. Here, since the startup processing program group has a smaller capacity than the function program group, according to the update processing described above, a case where the erase-write sequence is applied to the startup processing program group and the function program group collectively The probability that a failure occurs in the startup processing program group during the update processing can be reduced as compared with the case of the update processing.
[0027]
【The invention's effect】
As described above, according to the present invention, when a program is updated, occurrence of a failure due to the update can be suppressed.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration example of an electronic device to be updated according to an embodiment of the present invention.
FIG. 2 is a diagram showing an arrangement of programs on a ROM in the electronic device according to the embodiment of the present invention.
FIG. 3 is a flowchart illustrating a procedure of an update process according to the embodiment of the present invention.
FIG. 4 is a flowchart illustrating another procedure of the update process according to the embodiment of the present invention.
[Explanation of symbols]
1: CPU, 2: ROM, 3: RAM, 4: external storage medium interface, 5: external storage medium, 6: input interface, 7: input device, 8: display interface, 10: functional unit, 11: external input / output interface.

Claims (5)

An electronic device that functions by executing a program,
A rewritable nonvolatile memory storing the program,
On the non-volatile memory, a first program group for causing an electronic device to perform the function, a start processing program for initializing the electronic device and starting a program of the first program group, And a second program group including an update program for updating a program in the program group to a new program is divided and arranged so that each program group can be independently rewritten.
The electronic device, wherein the update program is a program that causes the electronic device to execute a process of updating a program of the first program group to a new program. The electronic device according to claim 1,
The update program updates the program of the first program group with a new program, verifies the normality of the update, and renews the program of the first program group when the verification of the normality fails. An electronic device, which is a program for causing the electronic device to execute a process. The electronic device according to claim 1 or 2,
The update program is a program that causes the electronic device to execute a process of updating a program of the first program group and a program of the second program group by a rewrite sequence of the nonvolatile memory that is independent of each other. Electronic equipment characterized by the above. The electronic device according to claim 3,
The electronic device, wherein the update program is a program that causes the electronic device to execute a process of first updating the activation processing program when a program of the second program group is updated. A program updating method for updating a program of an electronic device that performs a function by executing the program,
A first program group for causing the electronic device to perform the function in a rewritable nonvolatile memory of the electronic device, and a start-up processing program for initializing the electronic device and starting the program of the first program group And a second program group including an update program for updating a program of the first program group to a new program is divided and arranged so that each program group can be independently rewritten, and recorded. When,
By causing the electronic device to execute the update program, the electronic device updates the program of the first program group to a new program, verifies the normality of the update, and when the verification of the normality fails. Executing a process of updating the programs of the first program group again.

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