JP5225163B2 - Data update device, data update method for data update device, and data update program - Google Patents

Description

  The present invention relates to, for example, a data update device that updates F / W (firmware) of an embedded device, a data update method of the data update device, and a data update program.

Conventionally, in order to update the F / W of an embedded device to a new F / W, a medium such as a compact flash (registered trademark) card or USB memory storing the F / W image (data) is used. This is done by installing the F / W image in the embedded device. The installation refers to writing the F / W image into a nonvolatile memory in the embedded device.
However, when there are a plurality of embedded devices that are F / W update targets, it is necessary to update the F / W for each embedded device, which makes it difficult to update the F / W. In addition, it took time to complete the update of the F / W of all the embedded devices.

As a means for solving this problem, there is an F / W update method described in Patent Document 1.
In this method, a plurality of embedded devices and a management server are connected via a LAN (Local Area Network), the F / W image is transmitted from the management server to the embedded device, and the F / W is updated.
This eliminates the need to update the F / W for each embedded device, thereby reducing the time and complexity of the F / W update.

JP 2004-288106 A

In the method described in Patent Document 1, the entire F / W image is transmitted from the management server to the embedded device connected to the LAN, and the F / W is transmitted to a nonvolatile memory in the embedded device. I was writing the entire image. Further, when the nonvolatile memory needs to be erased in order to write data to the nonvolatile memory, the entire F / W image is written after erasing the F / W before update on the nonvolatile memory. It was out.
In this method, when the same byte string as the new F / W exists in the F / W before update written in the non-volatile memory, the same byte string is written in the corresponding part. In the case of an embedded device incorporating a non-volatile memory that needs to be erased, the same byte string is written after erasing the relevant part.
Updating the F / W by such a method requires redundant time for erasing the nonvolatile memory and writing the F / W image. In addition, the number of accesses to the nonvolatile memory becomes redundant, and the life of the nonvolatile memory is shortened.

  The present invention, for example, shortens the F / W update time of a plurality of embedded devices, and reduces the number of accesses to the nonvolatile memory incorporated in the plurality of embedded devices, thereby reducing the lifetime of the nonvolatile memory. The object is to provide an F / W update system that can be extended.

  The data updating device of the present invention includes a data storage unit that stores, using a storage medium, usage data that is used in a specific device and new data that is at least partially different from the usage data, and the data storage unit A used data dividing unit that divides the stored use data into a plurality of divided data with a specific size using a CPU (Central Processing Unit), and a plurality of new data stored in the data storage unit with the specific size A new data dividing unit that divides the divided data using a CPU, and whether or not the divided data of the used data and the arrangement order of the data correspond to the divided data of the new data corresponding to the divided data of the used data. Based on the difference information generated by the CPU and the difference information generated by the difference information generator. And using the CPU, each of the plurality of divided data of the new data is specified using the CPU, and each of the specified divided data is determined as the difference data by using the CPU. A difference data input unit that inputs to a device and causes the specific device to update a portion corresponding to the difference data in the usage data with the difference data.

  According to the present invention, for example, the F / W update time of a plurality of embedded devices is shortened, and the lifetime of the nonvolatile memory is reduced by reducing the number of accesses to the nonvolatile memory incorporated in the plurality of embedded devices. An F / W update system that can be extended can be provided.

1 is a configuration diagram of an F / W update system 100 according to Embodiment 1. FIG. FIG. 3 is a configuration diagram of a PC-side tool 210 in the first embodiment. FIG. 3 is a diagram illustrating an example of hardware resources of the personal computer 200 according to the first embodiment. FIG. 3 is a schematic diagram of an F / W update method according to the first embodiment. FIG. 3 is a schematic diagram of an F / W update method according to the first embodiment. 3 is a flowchart illustrating an F / W update method according to the first embodiment. 3 is a flowchart illustrating an F / W update method according to the first embodiment. The figure which shows the structure of the apparatus configuration management file 299 in Embodiment 1. FIG. 5 is a flowchart of pre-update F / W hash file creation processing (S120) according to the first embodiment. FIG. 6 is a relationship diagram between the pre-update F / W and the pre-update F / W hash file 292 according to the first embodiment. 5 is a flowchart of new F / W hash file creation processing (S130) according to the first embodiment. FIG. 4 is a schematic diagram of difference information file creation processing (S140) in the first embodiment. FIG. 6 is a schematic diagram of a pre-update F / W difference area erase process (S150) in the first embodiment. 6 is a flowchart of a pre-update F / W difference area erase process (S150) according to the first embodiment. FIG. 6 is a schematic diagram of a pre-update F / W difference area writing process (S160) in the first embodiment.

Embodiment 1 FIG.
An F / W update system that updates F / W (firmware) of each of a plurality of embedded devices to a new version of firmware will be described. However, F / W is an example of update target data.

FIG. 1 is a configuration diagram of the F / W update system 100 according to the first embodiment.
The configuration of the F / W update system 100 according to Embodiment 1 will be described below with reference to FIG.

The F / W update system 100 includes an embedded device (301 to 304) in which the F / W is incorporated, and a personal computer 200 (an example of a data update device) that updates the F / W of each embedded device to a new F / W 291. Have.
Each embedded device is connected to the personal computer 200 with a cable 101, and the personal computer 200 communicates with each embedded device through the cable 101. The cable 101 is an example of a communication line. For example, the personal computer 200 and each embedded device may communicate wirelessly.

The number of embedded devices may be less than four or five or more.
It is assumed that each F / W has not been altered by a virus or unauthorized access.
The processing speed of the personal computer 200 is assumed to be sufficiently fast. It is assumed that the processing speed of the embedded device and the access speed to the nonvolatile memory 390 built in the embedded device are slow. It is assumed that the communication speed of the cable 101 is sufficiently high.

  The F / W is written into the non-volatile memory 390 (an example of a storage medium or a storage device) to be incorporated (installed) in an embedded device. Writing means storage and setting.

Each embedded device includes an F / W update task 310, a nonvolatile memory 390, and a CPU (Central Processing Unit) (not shown). The non-updated F / W is stored in the nonvolatile memory 390.
The F / W update task 310 updates the incorporated F / W using the CPU with a new F / W 291 transmitted from the personal computer 200 by the command 110.

It is assumed that the F / W of the old version (for example, version “V ₁ ”) is incorporated in the embedded device A301 and the embedded device B302. Hereinafter, the F / W incorporated in the embedded device A301 and the embedded device B302 is referred to as “pre-update F / W (1) 391”.
It is assumed that a newer version (for example, version “V ₂ ”) of the F / W than the pre-update F / W (1) 391 is incorporated in the embedded device C303 and the embedded device D304. Hereinafter, the F / W incorporated and used in the embedded device C303 and the embedded device D304 is referred to as “pre-update F / W (2) 392”.
The pre-update F / W (1) 391 and the pre-update F / W (2) 392 are at least partially different in data. The data size of the pre-update F / W (1) 391 and the data size of the pre-update F / W (2) 392 may be the same or different.

The personal computer 200 includes a personal computer side tool 210 and a personal computer side storage unit 290.
The personal computer side tool 210 transmits a new F / W 291 to each embedded device with the command 110, and causes each embedded device to update the pre-update F / W.
The personal computer side storage unit 290 is a storage device that stores each data used in the personal computer 200 using a storage medium. For example, a new F / W 291 is stored in the personal computer side storage unit 290.
The new F / W 291 is an F / W of a version (for example, version “V ₃ ”) that is newer than each pre-update F / W. The new F / W 291 and each pre-update F / W are at least partially different in data. The data size of the new F / W 291 and the data size of each pre-update F / W may be the same or different.

FIG. 2 is a configuration diagram of the personal computer side tool 210 according to the first embodiment.
The configuration of the personal computer side tool 210 in the first embodiment will be described below with reference to FIG.

  The PC-side tool 210 includes a tool control unit 211, a pre-update F / W hash file creation unit 212 (an example of a used data division unit and a used data hash value calculation unit), and a new F / W hash file creation unit 213 (new data division). A difference data file creation unit 214 (an example of difference information generation unit), a difference data output unit 215 (an example of difference data input unit), and a personal computer side communication unit 219.

In addition to the new F / W 291, the personal computer side storage unit 290 (an example of a data storage unit) includes a device configuration management file 299, a pre-update F / W hash file 292, a new F / W hash file 293, and a difference information file 294. F / W (1) 391 before update and F / W (2) 392 before update are stored. The device configuration management file 299 is stored in advance by the system administrator. The pre-update F / W hash file 292, the new F / W hash file 293, and the difference information file 294 are the pre-update F / W hash file creation unit 212, the new F / W hash file creation unit 213, and the difference information file creation unit, respectively. Generated by 214 and stored. The pre-update F / W (1) 391 and the pre-update F / W (2) 392 are acquired from the embedded device by the pre-update F / W hash file creation unit 212 and stored.
Each “˜file” will be described later.

  The tool control unit 211 controls each “˜ unit” of the personal computer side tool 210 using a CPU.

The personal computer side communication unit 219 is a communication device that communicates with each embedded device.
For example, the personal computer side communication unit 219 transmits a command 110 including a new F / W 291 and a difference information file 294 to each embedded device. For example, the personal computer side communication unit 219 receives the pre-update F / W from each embedded device.

The pre-update F / W hash file creation unit 212 receives the pre-update F / W (an example of use data) from each embedded device using the personal computer side communication unit 219. The pre-update F / W hash file creation unit 212 receives the pre-update F / W (1) 391 from the embedded device A301 or the embedded device B302, and stores the received pre-update F / W (1) 391 in the personal computer side storage unit 290. To remember. The pre-update F / W hash file creation unit 212 receives the pre-update F / W (2) 392 from the embedded device C303 or the embedded device D304, and stores the received pre-update F / W (2) 392 in the personal computer side storage unit 290. To remember.
The pre-update F / W hash file creation unit 212 divides the pre-update F / W into a plurality of divided data with a specific block size using the CPU.

For example, before update F / W hash file creation unit 212, and before the update by embedded device A301 F / W (1) 391 write unit predetermined as the size of data written per one time for size _{W A} , before updating the size to be a common multiple of the previous updated by embedded device B302 F / W (1) a predetermined write unit size W _B 391 relative to the size of the data written to the per a block size F / W (1) 391 is divided.
Similarly, the pre-update F / W hash file creation unit 212 writes the write unit size W _C that is predetermined as the size of data written to the pre-update F / W (2) 392 by the embedded device C303. If, before updating the size to be a common multiple of the previous updated by embedded device D304 F / W (2) 392 for a predetermined write unit size W _D as the size of data written to per a block size F / W (2) 392 is divided.

Further, for example, before update F / W hash file creation unit 212, the erase and write unit size _{W A,} a write unit size _{W B,} per once for before updating the embedded device A301 F / W (1) 391 and the erase unit size E _a predetermined as the size of the data to be, before the update by embedded device B302 F / W (1) 391 for a predetermined erase unit as the size of the data to be erased in per dividing the pre-update F / W (1) 391 size to be a common multiple of the size _{E B} as the block size.
Erase Similarly, before update F / W hash file creation section 212, a write unit size _{W C,} and write unit size _{W D,} per once for before updating the embedded device C303 F / W (2) 392 The erase unit size E _C previously determined as the size of the data to be processed and the erase unit predetermined as the size of the data to be erased once for the pre-update F / W (2) 392 by the embedded device D304 dividing the pre-update F / W (2) 392 size to be a common multiple of the size _{E D} as the block size.
Erase means data deletion, initial value setting, and memory area initialization.

  Further, the pre-update F / W hash file creation unit 212 calculates a hash value for each divided data of the pre-update F / W using a predetermined hash function using the CPU. The pre-update F / W hash file creation unit 212 generates a pre-update F / W hash file 292 in which a hash value of each divided data of the pre-update F / W is set, and generates the generated pre-update F / W hash file 292. Store in the personal computer storage unit 290.

The new F / W hash file creation unit 213 divides a new F / W 291 (an example of new data) into a plurality of divided data with the block size of the F / W before update using a CPU.
Further, the new F / W hash file creation unit 213 uses the CPU to calculate a hash value for each new divided data of the F / W 291 using the hash function. The new F / W hash file creation unit 213 generates a new F / W hash file 293 in which the hash value of each divided data of the new F / W 291 is set, and the generated new F / W hash file 293 is stored on the personal computer side storage unit Store in 290.

The difference information file creation unit 214 determines whether the divided data of the F / W before update is the same as the divided data of the new F / W 291 corresponding to the divided data of the F / W before update and the arrangement order of the data. The difference information file 294 shown is generated using the CPU, and the generated difference information file 294 is stored in the personal computer storage unit 290.
For example, the difference information file creation unit 214 generates the difference information file 294 based on the hash value set in the pre-update F / W hash file 292 and the hash value set in the new F / W hash file 293. To do.
Further, for example, the difference information file creation unit 214 is the same as the divided data of the new F / W 291 corresponding to the divided data of the F / W before update corresponding to the divided data of the F / W before update corresponding to the arrangement order of the data. A difference information file 294 is generated by expressing whether or not by 1 bit.

Based on the difference information file 294, the difference data output unit 215 stores the divided data different from the pre-update F / W divided data corresponding to the data arrangement order among the plurality of divided data of the new F / W 291. Use to identify.
Further, the difference information file creation unit 214 transmits each divided data of the specified new F / W 291 as difference data to a specific embedded device using the personal computer side communication unit 219.

FIG. 3 is a diagram illustrating an example of hardware resources of the personal computer 200 according to the first embodiment.
In FIG. 3, a personal computer 200 includes a CPU 911 (also referred to as a microprocessor or a microcomputer). The CPU 911 is connected to the ROM 913, the RAM 914, the communication board 915, the display device 901, the keyboard 902, the mouse 903, the drive device 904, and the magnetic disk device 920 via the bus 912, and controls these hardware devices. The drive device 904 is a device that reads and writes a storage medium such as an FD (Flexible Disk Drive), a CD (Compact Disc), and a DVD (Digital Versatile Disc).

  The communication board 915 is wired or wirelessly connected to each embedded device via a communication network such as a LAN, the Internet, a telephone line (or directly).

  The magnetic disk device 920 stores an OS 921 (operating system), a window system 922, a program group 923, and a file group 924.

  The program group 923 includes programs that execute the functions described as “units” in the embodiment. The program is read and executed by the CPU 911. That is, the program causes the computer to function as “to part”, and causes the computer to execute the procedures and methods of “to part”.

  The file group 924 includes various data (input, output, determination result, calculation result, processing result, etc.) used in “˜part” described in the embodiment.

  In the embodiment, arrows included in the configuration diagrams and flowcharts mainly indicate input and output of data and signals.

  In the embodiment, what is described as “to part” may be “to circuit”, “to apparatus”, and “to device”, and “to step”, “to procedure”, and “to processing”. May be. That is, what is described as “to part” may be implemented by any of firmware, software, hardware, or a combination thereof.

4 and 5 are schematic diagrams of the F / W update method according to the first embodiment.
An overview of the F / W update method in the first embodiment will be described below based on FIG. 4 and FIG.

In FIG. 4, the personal computer side tool 210 of the personal computer 200 generates a new F / W hash file 293 in which the hash value of each block constituting the new F / W 291 is set (S 130), and the F / W before updating the embedded device. A pre-update F / W hash file 292 in which the hash value of each block constituting W is set is generated (S120).
The personal computer side tool 210 compares each hash value set in the new F / W hash file 293 with each hash value set in the pre-update F / W hash file 292, and stores the new F / W hash file 293. A difference information file 294 indicating whether each block and each block of the pre-update F / W hash file 292 are the same is generated (S140).
The personal computer side tool 210 transmits the generated difference information file 294 to the embedded device (S114).

In FIG. 5, the F / W update task 310 of the embedded device refers to the difference information file 294 transmitted from the personal computer side tool 210 and erases a block different from the new F / W 291 among the blocks of the pre-update F / W. (S150).
The personal computer side tool 210 refers to the difference information file 294, reads out a block different from the pre-update F / W from the new F / W 291 and transmits it to the embedded device (S161 to S163).
The F / W update task 310 writes the transmitted new F / W 291 block to the corresponding block of the pre-update F / W and updates the pre-update F / W (S164).

  “Sxxx” shown in FIGS. 4 and 5 corresponds to a process number in the flowchart described below.

6 and 7 are flowcharts illustrating the F / W update method according to the first embodiment.
The F / W update method (an example of the data update method) in the first embodiment will be described below with reference to FIGS.

  Each “unit” of the personal computer side tool 210 and the F / W update task 310 of each embedded device execute each process (S110 to S119) described below using the CPU.

The tool control unit 211 selects one embedded device from the device configuration management file 299 (S110).
The tool control unit 211 confirms whether the pre-update F / W hash file 292 corresponding to the version of the selected device F / W exists in the personal computer side storage unit 290 (S111). When the pre-update F / W hash file 292 does not exist, the pre-update F / W hash file creation unit 212 creates the pre-update F / W hash file 292 (S120).
The tool control unit 211 confirms whether the new F / W hash file 293 corresponding to the block size of the selected device F / W exists in the personal computer side storage unit 290 (S112). If there is no new F / W hash file 293, the new F / W hash file creation unit 213 creates a new F / W hash file 293 (S130).
The tool control unit 211 confirms whether or not the difference information file 294 corresponding to the pre-update F / W hash file 292 and the new F / W hash file 293 exists in the personal computer side storage unit 290 (S113). If there is no difference information file 294, the difference information file creation unit 214 creates the difference information file 294 (S140).
The personal computer side communication unit 219 transmits an erase command command including the difference information file 294 to the selected device (S114), and the F / W update task 310 of the selected device erases the difference area based on the difference information file 294 (S150). ).
The difference data output unit 215 transmits a write request command including the difference data of the new F / W 291 to the selected device based on the difference information file 294 (S161 to S163), and the F / W update task 310 of the selected device is the new F / W. The difference data of / W291 is written to the writing area of the F / W before update (S164). S161 to S164 are repeated until all the differential blocks of the new F / W 291 are written in the pre-update F / W (S165, S166).
S110 to S166 are repeated for each embedded device (S119).

  Details of each process (S110 to S119) will be described below.

<S110>
The tool control unit 211 refers to the device configuration management file 299 and selects one embedded device from a plurality of embedded devices.
The processing from S110 to S119 described later is looped.
For example, the tool control unit 211 selects the embedded devices in the order of the old version of the F / W before update, in the order set in the device configuration management file 299.

FIG. 8 is a diagram showing the configuration of the device configuration management file 299 according to the first embodiment.
The device configuration management file 299 according to the first embodiment will be described below with reference to FIG.

  In the device configuration management file 299, “embedded device”, “F / W version”, “erase unit size”, and “write unit size” are preset by the system administrator.

“Embedded device” indicates identification information (for example, name) of each embedded device.
“F / W version” indicates version information (for example, version number) of the pre-update F / W incorporated in the embedded device.
“Erase unit size” indicates the size of data to be erased once per F / W before update by the embedded device.
“Writing unit size” indicates the size of data written per time by the embedded device to the pre-update F / W.

  Assume that the erase unit size and the write unit size are smaller than the data size of the pre-update F / W.

In S110 (FIG. 6), the tool control unit 211 performs the installation that is set in the device configuration management file 299 first in the embedded device A301 and the embedded device B302 having the oldest version of the pre-update F / W in the first loop. Assume that the device A301 is selected, and the embedded device B302 is selected in the second loop.
In addition, the tool control unit 211 selects the embedded device C303 previously set in the device configuration management file 299 among the embedded device C303 and the embedded device D304 having the next oldest F / W version before update at the third loop. In the fourth loop, the embedded device D304 is selected.

  The description of the F / W update method (FIGS. 6 and 7) will be continued.

  After S110, the process proceeds to S111.

<S111>
The tool control unit 211 confirms whether or not the pre-update F / W hash file 292 corresponding to the pre-update F / W version of the embedded device selected in S110 (hereinafter referred to as “selected device”) exists in the personal computer side storage unit 290. To do.
The pre-update F / W hash file 292 is created for each version of the pre-update F / W.

  If the pre-update F / W hash file 292 exists, the process proceeds to S112. If the pre-update F / W hash file 292 does not exist, the process proceeds to S120.

At the first loop (selected device is “embedded device A301”), since there is no pre-update F / W hash file 292, the process proceeds to S120, and the pre-update F / W hash file 292 is generated in S120.
At the time of the second loop (selected device is “embedded device B302”), the version of the pre-update F / W of the built-in device A301 is the same as the version of the pre-update F / W of the built-in device B302 (see FIG. 8). The pre-update F / W hash file 292 generated at the time of the loop becomes the pre-update F / W hash file 292, and the process proceeds to S112.
In the third loop (the selected device is “embedded device C303”), since there is no pre-update F / W hash file 292, the process proceeds to S120, and the pre-update F / W hash file 292 is generated in S120. .
At the time of the fourth loop (selected device is “embedded device D304”), the F / W before update of the embedded device C303 and the F / W before update of the embedded device D304 are the same (see FIG. 8), 3 The pre-update F / W hash file 292 generated at the time of the second loop becomes the pre-update F / W hash file 292, and the process proceeds to S112.

<S120: F / W hash file creation process before update>
Based on the device configuration management file 299, the pre-update F / W hash file creation unit 212 creates a pre-update F / W hash file 292 corresponding to the pre-update F / W version of the selected device.
The pre-update F / W hash file 292 is data in which the hash values of the respective blocks are arranged in the order of the pre-update F / W blocks divided by the specific block size corresponding to the pre-update F / W version of the selected device. .
Hereinafter, the pre-update F / W of the selected device is referred to as “selected device F / W”.

FIG. 9 is a flowchart of the pre-update F / W hash file creation process (S120) in the first embodiment.
The pre-update F / W hash file creation process (S120) in the first embodiment will be described below with reference to FIG.

<S121>
Based on the device configuration management file 299, the pre-update F / W hash file creation unit 212 identifies an embedded device having the same version of the pre-update F / W as the selected device.
When the selected device is “embedded device A301”, the identified embedded device is “embedded device B302” (see FIG. 8).
After S121, the process proceeds to S122.

<S122>
Based on the device configuration management file 299, the pre-update F / W hash file creation unit 212 selects the “erase unit size” of the selected device, the “write unit size” of the selected device, and the specified device (the embedded device specified in S121). The least common multiple of the “erase unit size” and the “write unit size” of the specific device is calculated as a block size.
A selection device is "embedded device A301", when a particular device is a "embedded device B302", before update F / W hash file creation unit 212 _{"E A", "W A", "E B" "W B"} Is calculated as a block size (see FIG. 8).

The block size need not be the least common multiple as long as it is a common multiple of the “write unit size” and the “erase unit size”. Further, if erasing is unnecessary, the block size may be a common multiple of the “write unit size”.
However, as the block size increases, the granularity of the difference information of the two F / Ws increases, and the possibility that the data of one block will differ increases, and as a result, the update rate of the F / W may decrease. Becomes higher.

  After S122, the process proceeds to S123.

<S123>
The pre-update F / W hash file creation unit 212 divides the selected device F / W into a plurality of blocks with the block size calculated in S122.
After S123, the process proceeds to S124.

<S124>
The pre-update F / W hash file creation unit 212 calculates a hash value for each of the plurality of blocks obtained in S123, using a predetermined hash function.
Two pieces of data having the same hash value calculated using the same hash function are the same data.
For the hash function, the smaller the calculation amount and the hash length, the better the processing speed.
After S124, the process proceeds to S125.

<S125>
The pre-update F / W hash file creation unit 212 creates a pre-update F / W hash file 292 in which the hash value of each block calculated in S124 is set.
After S125, the process proceeds to S126.

<S126>
The pre-update F / W hash file creation unit 212 stores the pre-update F / W hash file 292 created in S125 in the personal computer side storage unit 290.
After S126, the pre-update F / W hash file creation process (S120) ends.

FIG. 10 is a relationship diagram between the pre-update F / W and the pre-update F / W hash file 292 according to the first embodiment.
In each figure including FIG. 10, “0x” means hexadecimal notation. For example, “0xFF” indicates the decimal number “255”.
As shown in FIG. 10, when the block size is “3 bytes”, the pre-update F / W is divided into 3 bytes (S123), and each block (first block, second block,...) The hash value is calculated (S124), and the hash value of each block is sequentially set in the pre-update F / W hash file 292 (S125).

  Returning to FIG. 6, the description of the F / W update method will be continued.

  After S120, the process proceeds to S112.

<S112>
The tool control unit 211 confirms whether the new F / W hash file 293 corresponding to the block size of the selected device F / W (the value calculated in S122) exists in the personal computer side storage unit 290.
A new F / W hash file 293 is created for each block size.

  If the new F / W hash file 293 exists, the process proceeds to S113. If the new F / W hash file 293 does not exist, the process proceeds to S130.

At the first loop (selected device is “embedded device A301”), since there is no new F / W hash file 293, the process proceeds to S130, and the new F / W hash file 293 is generated in S130.
During the second loop (the selected device is “embedded device B302”), since the F / W before update of the embedded device A301 and the F / W before update of the embedded device B302 are common (see S122), the first time The new F / W hash file 293 generated at the time of the loop becomes the new F / W hash file 293, and the process proceeds to S113.
If the block size of the pre-update F / W of the embedded device A301 and the pre-update F / W of the embedded device C303 is the same at the third loop (selected device is “embedded device C303”) The new F / W hash file 293 thus made becomes the new F / W hash file 293, and the process proceeds to S113.
If the block size of the F / W before update of the embedded device A301 and the F / W before update of the embedded device C303 are different at the third loop (selected device is “embedded device C303”), the new F / W hash file Since there is no 293, the process proceeds to S130, and the new F / W hash file 293 is generated in S130.
At the time of the fourth loop (the selected device is “embedded device D304”), the F / W before update of the embedded device C303 and the F / W before update of the embedded device D304 are common (see S122), the third time The new F / W hash file 293 generated at the time of the loop (or at the first loop) becomes the new F / W hash file 293, and the process proceeds to S113.

<S130: New F / W hash file creation process>
The new F / W hash file creation unit 213 creates a new F / W hash file 293 corresponding to the block size of the selected device F / W in the same manner as the pre-update F / W hash file creation unit 212 in S120.
The new F / W hash file 293 is data in which the hash values of the respective blocks are arranged in the block order of the new F / W 291 divided by the block size of the selected device F / W.

FIG. 11 is a flowchart of the new F / W hash file creation process (S130) in the first embodiment.
The new F / W hash file creation process (S130) in the first embodiment will be described below based on FIG. 10 and FIG.

The new F / W hash file creation unit 213 divides the new F / W 291 into a plurality of blocks with the block size (value calculated in S122) (S131), and a predetermined hash function (the hash function used in S124) Is used to calculate a hash value for each divided block (S132).
Then, the new F / W hash file creation unit 213 creates a new F / W hash file 293 in which the hash value of each block is set (S133), and stores the new F / W hash file 293 in the personal computer side storage unit 290. (S134).

  Returning to FIG. 6, the description of the F / W update method will be continued.

  After S130, the process proceeds to S113.

<S113>
The tool control unit 211 stores a difference information file corresponding to the pre-update F / W hash file 292 corresponding to the version of the selected device F / W and the new F / W hash file 293 corresponding to the block size of the selected device F / W. It is confirmed whether 294 is in the personal computer side storage unit 290.
The difference information file 294 is created for each combination of the pre-update F / W hash file 292 and the new F / W hash file 293.

  If the difference information file 294 exists, the process proceeds to S114. If the difference information file 294 does not exist, the process proceeds to S140.

At the first loop (the selected device is “embedded device A301”), since there is no difference information file 294, the process proceeds to S140, and the difference information file 294 is generated in S140.
During the second loop (the selected device is “embedded device B302”), the version and block size of the pre-update F / W of the built-in device A301 and the pre-update F / W of the built-in device B302 are common. The generated difference information file 294 becomes the difference information file 294, and the process proceeds to S114.
In the third loop (the selected device is “embedded device C303”), since there is no new F / W hash file 293, the process proceeds to S140, and the difference information file 294 is generated in S140.
Since the version and block size of the pre-update F / W of the embedded device C303 and the pre-update F / W of the embedded device D304 are common at the time of the fourth loop (selected device is “embedded device D304”), the third loop The difference information file 294 generated at this time becomes the difference information file 294, and the process proceeds to S114.

<S140: Difference information file creation process>
Based on the pre-update F / W hash file 292 corresponding to the version of the selected device F / W and the new F / W hash file 293 corresponding to the block size of the selected device F / W, the difference information file creation unit 214 A difference information file 294 is created.
The difference information file 294 is obtained by comparing the hash value set in the pre-update F / W hash file 292 and the hash value set in the new F / W hash file 293 one by one in order (1 bit ( Bit string data indicated by a match “0” and a mismatch “1”).

FIG. 12 is a schematic diagram of difference information file creation processing (S140) in the first embodiment.
The difference information file creation process (S140) in the first embodiment will be described below with reference to FIG.

For example, when the pre-update F / W hash file 292 and the new F / W hash file 293 indicate the values in FIG. 12, the difference information file creation unit 214 creates the difference information file 294 as follows.
First, the difference information file creation unit 214 matches the first hash value “0xFF” of the pre-update F / W hash file 292 with the first hash value “0xFF” of the new F / W hash file 293. A bit “0” indicating “match” is set in the first bit of the difference information file 294.
Next, the difference information file creation unit 214 does not match the second hash value “0x3C” of the pre-update F / W hash file 292 and the second hash value “0x00” of the new F / W hash file 293. The bit “1” indicating “mismatch” is set to the second bit of the difference information file 294.
Similarly, the difference information file creation unit 214 compares the xth hash value of the pre-update F / W hash file 292 and the xth hash value of the new F / W hash file 293, and if they match, Bit “0” is set to the x bit of the information file 294, and if they do not match, bit “1” is set to the x bit of the difference information file 294.

As described above, since two pieces of data having the same hash value calculated using the same hash function are the same data, the bit “0” set in the difference information file 294 indicates the relevant device F / W. The block and the block of the new F / W 291 indicate the same data, and the bit “1” set in the difference information file 294 indicates that the block of the selected device F / W and the block of the new F / W 291 are Indicates different data.
That is, in the difference information file 294 of FIG. 12, when the block size is “3 bytes”, the first block of the selected device F / W (data of 3 bytes from the top) and the first block of the new F / W 291 are the same data. It is shown that.
Further, the second block (3 bytes data from the fourth byte) of the selected device F / W and the second block of the new F / W 291 are different data.

  Returning to FIG. 6, the description of the F / W update method will be continued.

  After S140, the process proceeds to S114.

<S114>
The tool control unit 211 stores a difference information file corresponding to the pre-update F / W hash file 292 corresponding to the version of the selected device F / W and the new F / W hash file 293 corresponding to the block size of the selected device F / W. And an erase request command including the block size of the selected device F / W.
The tool control unit 211 transmits the generated erase command command to the selected device using the personal computer side communication unit 219.
The erase request command is a command 110 for requesting erasure of the difference area of the selected device F / W.
The difference area means a block whose data is different from the corresponding block of the new F / W 291 (the block corresponding to the arrangement order in the F / W) among the blocks of the selected device F / W.
Erase means data deletion, initial value setting, memory area initialization, and the like.
After S114, the process proceeds to S150.

<S150: Pre-update F / W difference area erase process>
The F / W update task 310 of the selected device receives the erase request command transmitted in S114, and based on the difference information file 294 and the block size included in the received erase command command, determines the difference area of the F / W before update. Erase.

FIG. 13 is a schematic diagram of the pre-update F / W difference area erase process (S150) in the first embodiment.
The outline of the pre-update F / W difference area erase process (S150) in the first embodiment will be described below with reference to FIG.

When the bit of the difference information file 294 is the bit “0” indicating the matching of the corresponding block between the pre-update F / W and the new F / W 291 (S153), the F / W update task 310 corresponds to the bit. Do not erase the F / W block before update.
When the bit of the difference information file 294 is a bit “1” indicating a mismatch between corresponding blocks of the pre-update F / W and the new F / W 291 (S153), the F / W update task 310 corresponds to the bit. The F / W block before update is specified (S154), and the specified block is erased by a predetermined erase unit size (S155).
The erase unit size is a data size per time that the F / W update task 310 can erase the pre-update F / W.

In FIG. 13, the F / W update task 310 does not erase the first block of the F / W before update because the first bit (first bit) of the difference information file 294 is “0”.
Further, since the second bit of the difference information file 294 is “1”, the F / W update task 310 erases the second block of the F / W before update for each erase unit size.

  S153 to S155 in the figure correspond to the processing numbers in the flowchart described below.

FIG. 14 is a flowchart of the pre-update F / W difference area erase process (S150) according to the first embodiment.
The flow of the pre-update F / W difference area erase process (S150) in the first embodiment will be described below with reference to FIG.

<S151>
The F / W update task 310 of the selected device receives an erase request command including the difference information file 294 and the block size.
After S151, the process proceeds to S152.

<S152>
The F / W update task 310 acquires 1 bit from the difference information file 294.
The processing from S152 to S157 described later is looped.
The F / W update task 310 acquires the first bit (first bit) of the difference information file 294 during the first loop, and acquires the second bit of the difference information file 294 during the second loop.
When the difference information file 294 is 5 bits, S152 to S157 loop five times.
After S152, the process proceeds to S153.

<S153>
In the F / W update task 310, the 1 bit acquired in S152 (hereinafter referred to as “acquired bit”) is a bit “0” indicating the matching of the corresponding block between the pre-update F / W and the new F / W 291. Or a bit “1” indicating a mismatch between corresponding blocks of the pre-update F / W and the new F / W 291.
If the acquired bit is “0”, the process proceeds to S157, and if the acquired bit is “1”, the process proceeds to S154.

<S154>
Based on the block size included in the difference information file 294, the F / W update task 310 selects a block (hereinafter referred to as “difference block”) corresponding to the acquired bit (bit “1”) from the pre-update F / W. Identify.
For example, when the block size is “12 bytes” and the acquired bit is the first bit of the difference information file 294, the difference block is an area of 12 bytes from the top of the difference information file 294.
When the acquired bit is the second bit of the difference information file 294, the difference block is a 12-byte area from the 13th byte of the difference information file 294.
After S154, the process proceeds to S155.

<S155>
The F / W update task 310 erases the difference block specified in S154 by the erase unit size.
S155 and later-described S156 are loop-processed.
When the erase unit size is “3 bytes”, the F / W update task 310 erases the area of 3 bytes from the top of the difference block at the first loop, and from the 4th byte of the difference block at the second loop. Erase byte area.
When the block size is “12 bytes” and the erase unit size is “3 bytes”, S155 to S156 loop 4 times (= 12 ÷ 3).
After S155, the process proceeds to S156.

<S156>
The F / W update task 310 determines in step S155 whether the erasure of all areas of the difference block has been completed.
When the erasure of the difference block is completed (YES), the process proceeds to S157.
If the erasure of the difference block has not been completed (NO), the process returns to S155.

<S157>
The F / W update task 310 determines that the processing of the difference information file 294 has been completed when all the bits of the difference information file 294 have been acquired in S142, and there are bits that have not been acquired in the difference information file 294 in S142. It is determined that the processing of the difference information file 294 has not been completed.
When the process of the difference information file 294 is completed (YES), the pre-update F / W difference area erase process (S150) ends.
When the process of the difference information file 294 has not been completed (NO), the process returns to S152.

  Returning to FIG. 6, the description of the F / W update method will be continued.

  After S150, the process proceeds to S160 (FIG. 7).

<S160: F / W differential area writing process before update>
The difference data output unit 215 transmits the new F / W291 difference area data to the selected device in units of writing unit sizes, and the F / W update task 310 of the selected device receives the received new F / W291 difference area data before the update. The F / W before update is updated by writing to the F / W (S161 to S166).

FIG. 15 is a schematic diagram of the pre-update F / W difference area writing process (S160) in the first embodiment.
An overview of the pre-update F / W difference area writing process (S160) in the first embodiment will be described below with reference to FIG.

When the bit of the difference information file 294 is the bit “0” indicating the coincidence of the corresponding block between the pre-update F / W and the new F / W 291, the personal computer side tool 210 sets the new F / W 291 corresponding to the bit. The block is not transmitted to the embedded device (selected device) (S161).
If the bit of the difference information file 294 is a bit “1” indicating that the corresponding block of the pre-update F / W and the new F / W 291 does not match, the personal computer side tool 210 has a new F / W 291 corresponding to the bit. A block is specified (S161), the specified block is read in units of a predetermined writing unit size (S162), and the read difference data is transmitted to an embedded device (selected device) (S163).
The write unit size is a data size per time that the F / W update task 310 of the embedded device can write in the memory area of the pre-update F / W, and is set in the device configuration management file 299.

In FIG. 15, the personal computer side tool 210 does not transmit the first block of the new F / W 291 because the first bit (first bit) of the difference information file 294 is “0”.
Further, since the second bit of the difference information file 294 is “1”, the personal computer side tool 210 reads and transmits the second block of the new F / W 291 for each writing unit size.

  The F / W update task 310 of the embedded device writes each difference data transmitted by the F / W update task 310 in the corresponding area of the pre-update F / W (S164).

  S161 to S164 in the figure correspond to the process numbers of the flowcharts described below.

  Returning to FIG. 7, the description of the F / W update method is continued from S161 of S160.

<S161>
The difference data output unit 215 searches the difference information file 294 for a bit whose value is “1”, and identifies one new F / W 291 difference block corresponding to the bit whose value is “1”.
The processing from S161 to S166 described later is looped.
The difference data output unit 215 specifies a new F / W291 difference block corresponding to the first bit among the bits having a value of “1” in the difference information file 294 during the first loop, and the second loop Sometimes a new F / W291 differential block corresponding to the second bit (bit value “1”) is identified.
If the first bit (first bit) of the difference information file 294 is “1”, the first block (first block) of the new F / W 291 is a difference block. If the second bit of the difference information file 294 is “1”, the second block of the new F / W 291 is a difference block.
When the difference information file 294 has five bits having a value “1”, S161 to S166 loop five times.
After S161, the process proceeds to S162.

<S162>
The difference data output unit 215 reads the data of the difference specifying block (the new F / W291 difference block specified in S161) by the writing unit size of the selected device F / W. The writing unit size of the selected device F / W is set in the device configuration management file 299.
The processing from S162 to S165 described later is looped.
When the write unit size is “4 bytes”, the difference data output unit 215 reads the 4-byte area from the beginning of the difference specifying block at the first loop, and 4 bytes from the fifth byte of the difference specifying block at the second loop. Read a byte area.
When the block size is “12 bytes” and the write unit size is “4 bytes”, S162 to S165 loop three times (= 12 ÷ 4).
After S162, the process proceeds to S163.

<S163>
The difference data output unit 215 includes difference unit data (data read in S162), write area information indicating an area in which the difference unit data is written (for example, the number of bytes from the beginning of the new F / W 291 to the beginning of the difference unit data), and A write request command including is generated.
The differential data output unit 215 transmits the generated write request command to the selected device using the personal computer side communication unit 219.
The write request command is a command 110 for requesting writing of differential unit data to the memory area of the selected device F / W.
After S163, the process proceeds to S164.

<S164>
The F / W update task 310 of the selected device receives the write request command including the difference unit data and the write area information, and writes the difference unit data in the pre-update F / W write area.
After S164, the process proceeds to S165.

<S165>
The difference data output unit 215 determines that the processing of the difference identification block has been completed when all the data of the difference identification block has been read in S162, and if there is data that has not been read from the difference identification block in S162, It is determined that the process has not been completed.
When the process of the difference specifying block is completed (YES), the process proceeds to S165.
When the process of the difference specifying block has not been completed (NO), the process returns to S162.

<S166>
The difference data output unit 215 determines that the processing of all the difference blocks has been completed when all the difference blocks of the new F / W 291 are specified in S161, and there is a difference block that is not specified in the new F / W 291 in S161 It is determined that the processing of all the difference blocks has not been completed.
When the process for all the difference blocks is completed (YES), the process proceeds to S119.
If all the difference blocks have not been processed (NO), the process returns to S161.

<S119>
The tool control unit 211 determines that the processing for all the embedded devices is completed when all the embedded devices are selected in S110, and does not complete the processing for all the embedded devices when there is an embedded device that is not selected in S110. Is determined.
When the processing of all the embedded devices is completed (YES), the F / W update method ends.
If the processing for all the embedded devices has not been completed (NO), the processing returns to S110.

In the first embodiment, for example, the following F / W update method has been described.
A new F / W is transmitted from the personal computer to the plurality of embedded devices via a cable, and the pre-update F / W on the nonvolatile memory incorporated in the plurality of embedded devices is updated to a new F / W.

In the F / W update of the embedded device by the F / W update system according to the first embodiment, the entire F / W before update on the nonvolatile memory is not erased, but the new F / W and the F / W before update are updated. Erase only the difference between them. Also, instead of writing all the data of the new F / W, the difference between the new F / W and the F / W before update is transmitted from the personal computer side tool to the embedded device and written.
When updating the F / W of an embedded device having a built-in nonvolatile memory that does not require erasing for data writing, the above-described erasing process is not necessary.
By doing so, the number of access areas to the nonvolatile memory is reduced, and the amount of new F / W data transmitted from the personal computer side tool to the embedded device is reduced. As a result, the F / W update speed of the embedded device is improved, and the lifetime of the nonvolatile memory is extended.
Further, this method can be applied to both an embedded device incorporating a non-volatile memory that requires erasing for writing data and an embedded device incorporating a non-volatile memory that does not require erasing.

  When updating the F / W, a difference information file between the new F / W and the pre-update F / W is used. If the difference information file is not on the computer, create a new one. The created difference information file can be used for updating a plurality of other embedded devices that store the same version of the pre-update F / W. The difference information file can be used each time the F / W of one embedded device is updated. There is no need to create it. In addition, the erase unit of each of the plurality of embedded devices may be different from the data writing unit. Since the difference information file is created using the hash file of the new F / W and the hash file of the pre-update F / W, the difference between the new F / W and the pre-update F / W can be detected at high speed. . Therefore, the difference information file can be created at high speed. The created hash file of the new F / W and the hash file of the pre-update F / W can be used to create a difference information file when updating a plurality of other embedded devices. There is no need to create the hash file every time W is updated. As a result, the F / W update time of a plurality of embedded devices can be shortened, and the lifetime of the nonvolatile memory can be extended by reducing the number of accesses to the nonvolatile memory incorporated in the plurality of embedded devices. Become.

The F / W update method has the following means.
(1) Means for knowing erase unit of nonvolatile memory built in a plurality of embedded devices connected to the personal computer, F / W write unit, and F / W version stored in the nonvolatile memory (Device configuration management file 299).
(2) Means for creating the new F / W hash file and the pre-update F / W hash file (pre-update F / W hash file 292, new F / W hash file 293).
(3) A means for determining a block size when creating the hash file (pre-update F / W hash file 292).
(4) Means for creating a difference information file between the new F / W and the pre-update F / W from the hash file (difference information file 294).
(5) Means for referring to the difference information file and erasing the pre-update F / W on the non-volatile memory only at the difference between the new F / W and the pre-update F / W (F / W update) Task 310).
(6) A means for referring to the difference information file, transmitting only the difference portion of the new F / W from the personal computer to the embedded device, and writing it in the nonvolatile memory (difference data output unit 215, F / W update) Task 310).
(7) An existing F / W before update of an embedded device that is different from the embedded device in which an F / W before update of the same version as the F / W before update stored in the embedded device is stored. Means for using the hash file and the existing difference information file (pre-update F / W hash file 292, new F / W hash file 293, difference information file 294).

  The F / W update system calculates a hash value in units of a fixed block size for the pre-update F / W and the new F / W stored in the embedded device, and if the hash values are the same, “0”. “0”, “0” is regarded as a bit value “0”, “1” is regarded as a bit value “1”, and the column of bit values is regarded as the pre-update F / W and the new F / W. Difference information from W is assumed.

  Further, the hash file and the difference information file created when updating the F / W of one embedded device are reused for updating the F / W of another embedded device.

  In addition, an existing hash file created when updating the F / W of another embedded device is used to create the difference information file. If there is no hash file, a hash file necessary for creating the difference information file Create a new.

  The block size at the time of creating the hash file is the least common multiple of the erase unit and the data write unit of each nonvolatile memory of a plurality of embedded devices that store the same version of the pre-update F / W. Even if the erase unit and the data writing unit are different among the plurality of embedded devices, the same difference information file can be used to update the F / W of the plurality of embedded devices.

  100 F / W update system, 101 cable, 110 command, 200 PC, 210 PC side tool, 211 Tool control unit, 212 F / W hash file creation unit before update, 213 New F / W hash file creation unit, 214 Difference information File creation unit, 215 Difference data output unit, 219 PC side communication unit, 290 PC side storage unit, 291 New F / W, 292 F / W hash file before update, 293 New F / W hash file, 294 Difference information file, 299 Device configuration management file, 301 Embedded device A, 302 Embedded device B, 303 Embedded device C, 304 Embedded device D, 310 F / W update task, 390 Non-volatile memory, 391 F / W (1) before update, 392 Update Previous F / W (2), 901 Display device, 902 keyboard, 903 mouse, 904 drive device, 911 CPU, 912 bus, 913 ROM, 914 RAM, 915 communication board, 920 magnetic disk device, 921 OS, 922 window system, 923 program group, 924 file group.

Claims (6)

A data storage unit, a use data dividing unit, a new data dividing unit, a difference information generating unit, and a difference data input unit;
The data storage unit includes one or more usage data that is used by a plurality of specific equipment, said one or more at least partially different from the new data from the usage data, device configuration management file and the storage medium A storage unit for storing using
The device configuration management file includes a device name that identifies a specific device, a version of use data that is used by the specific device, a write unit size that indicates the size of data to be written to the specific device once, Is a file that associates
The usage data dividing unit selects any one of the device names included in the device configuration management file as a selected device name, and corresponds to the selected device name among the device names included in the device configuration management file. Specify the device name associated with the same version as the assigned version as the specific device name,
The use data dividing unit calculates, as a specific size, a size that is a common multiple of a write unit size associated with the selected device name and a write unit size associated with the specific device name,
The usage data dividing unit, CPU (Central Processing usage data of the same version as the version associated with the selected device name into a plurality of divided data with the particular size of the usage data stored in the data storage unit Unit) resolved using,
The new data dividing unit divides a CPU into a plurality of divided data in the data storage unit the specific size stored new data to,
The difference information generating unit determines whether the divided data of the used data is the same as the divided data of the new data corresponding to the divided data of the used data and the arrangement order of the data for each divided data of the used data . generated using the CPU as the difference information information indicating,
The difference data input unit stores each divided data different from the divided data of the use data corresponding to the data arrangement order among the plurality of divided data of the new data based on the difference information generated by the difference information generating unit. used to identify it, wherein the selection device identified by the selected device name the said selected device to enter into a specific device identified by the specific device name specified equipment the divided data of the new data specified as difference data a portion corresponding to the difference data in the usage data Ru is updated with the differential data in preparative
Data update apparatus according to claim and this. The device configuration management file includes an erase unit size indicating the size of data to be erased from a specific device at one time in association with a device name for identifying the specific device.
The use data dividing unit includes a writing unit size associated with the selected device name, a writing unit size associated with the specific device name, an erase unit size associated with the selected device name, Calculate the size which is a common multiple of the erase unit size associated with the specific device name as the specific size,
The use data dividing unit divides the use data into a plurality of divided data with the specific size.
The data updating apparatus according to claim 1, wherein: The data update device further includes:
A use data hash value calculation unit that calculates a hash value for each divided data of the use data using a CPU by a predetermined hash function;
A new data hash value calculation unit that calculates a hash value for each divided data of the new data using the CPU by the hash function;
The difference information generation unit generates the difference information based on the hash value calculated by the use data hash value calculation unit and the hash value calculated by the new data hash value calculation unit. The data update device according to claim 1 or 2 . The difference information generation unit represents, for each divided data of the use data, whether or not the divided data of the use data and the data arrangement order are the same as the divided data of the new data corresponding to the one bit. generating a data updating apparatus according to any one of claims 1 to 3, characterized in. A data updating method for a data updating device comprising a data storage unit, a used data dividing unit, a new data dividing unit, a difference information generating unit, and a difference data input unit,
The data storage unit stores one or more usage data used in a plurality of specific devices, new data at least partially different from the one or more usage data, and a device configuration management file. A storage unit for storing using
The device configuration management file includes a device name that identifies a specific device, a version of use data that is used by the specific device, a write unit size that indicates the size of data to be written to the specific device once, Is a file that associates
The usage data dividing unit selects one of the device names included in the device configuration management file as a selected device name, and corresponds to the selected device name among the device names included in the device configuration management file Specify the device name associated with the same version as the assigned version as the specific device name,
The use data dividing unit calculates a size that is a common multiple of a writing unit size associated with the selected device name and a writing unit size associated with the specific device name as a specific size,
The usage data division unit, CPU (Central Processing usage data of the same version as the version associated with the selected device name into a plurality of divided data with the particular size of the usage data stored in the data storage unit Unit),
The new data dividing unit divides new data at least partially different from the use data into a plurality of divided data with the specific size using a CPU,
The difference information generating unit, wherein the data segment of the usage data for each data segment of the usage data, whether order of divided data and data of the usage data is the divided data of the new data corresponding the same Is generated using the CPU as the difference information,
The differential data input unit, the difference information divided data divided data different from the new data using the data arrangement order of the data among the plurality of divided data of the new data corresponding based on the difference information generated by the generating unit were identified using a CPU, a said selected device to enter into a specific device identified by the specified equipment name select device identified by the selected device name of each data segment of new data identified as difference data A data updating method for a data updating apparatus, comprising causing the specific device to update a portion corresponding to the difference data in the usage data with the difference data. A data update program for causing a computer to execute the data update method according to claim 5 .

Images