JP2006338350A - Data control system and program - Google Patents

Abstract

The present invention provides a data control system and a program that reduce complicated processing when a plurality of devices are recognized, and can be applied to a small electronic device.
A data control system includes first to n-th devices 50 and 80 that are targets of data transfer via a bus and partition management information of first to n-th devices 50 and 80 based on first to first devices. The virtual management information creation unit 62 that creates virtual management information for recognizing the nth devices 50 and 80 as one device, and the first to nth devices 50 and 80 specify the logical address of one device. When the read or write access is requested, the device designation information for designating one of the first to nth devices 50 and 80 and the physical corresponding to the logical address based on the virtual management information and the logical address A device control unit 64 that calculates an address and controls access to the device.
[Selection] Figure 1

Description

  The present invention relates to a data control system and a program.

  The USB mass storage class is known as a standard for supporting an external storage device as one of upper layer protocols of the USB standard. In the USB mass storage class, each of a plurality of devices is recognized as an individual device on the protocol. For this reason, when handling a plurality of devices in the USB mass storage class, for example, it is necessary to manage a plurality of devices. This management is complicated, and some small electronic devices can handle only a single device. is there.

One of a communication means for transmitting / receiving information to / from other devices, a vendor-unique declaration that enables remote control by another device, and a storage class declaration that functions as a recording means for the other device. A configuration including setting means for setting is known (see Patent Document 1).
JP 2001-186395 A

  However, in the above configuration, it is necessary to set one of declarations of a functioning storage class, and for example, a plurality of storage devices cannot be recognized simultaneously.

  In addition, in an electronic apparatus having a plurality of devices, complicated data control processing has to be performed on the USB mass storage class when it is recognized as an individual device on the protocol.

  The present invention has been made in view of the technical problems as described above. The object of the present invention is to reduce complicated processing when recognizing a plurality of devices, and also to a small electronic device. An object is to provide a data control system and a program that can be applied.

  According to the present invention, the first to n-th devices (n is an integer of 2 or more) to be transferred via the bus and the partition management information of the first to n-th devices, the first to first a virtual management information creating unit for creating virtual management information for recognizing n devices as one device, the first to nth devices are recognized as one device based on the virtual management information, and the 1 Device designation information for designating one of the first to nth devices based on the virtual management information and the logical address when a read or write access is requested by designating a logical address of one device And a device control unit that calculates a physical address corresponding to the logical address and controls access to the device.

  According to the present invention, since a plurality of devices can be recognized as a single device by an external device or the like, it is possible to access the plurality of devices from the external device or the like without requiring complicated processing.

  In the present invention, the virtual management information creation unit creates the virtual management information by copying the boot information of the management information of any of the first to nth devices into the boot information of the virtual management information. You may make it do.

  In the present invention, the virtual management information creation unit copies the partition management information of the first device among the first to nth devices to the first partition information of the virtual management information, and Virtual management information may be created.

  Thereby, when controlling access to the first device, the logical address from the external device or the like can be used as it is as the physical address of the first device.

  In the present invention, the virtual management information creation unit performs a process of offsetting a partition start address with respect to partition management information of the second to n-th devices among the first to n-th devices. And the result may be used for the second to n-th partition information of the virtual management information.

  Thereby, virtual management information for recognizing a plurality of devices as one device can be created.

  In the present invention, the device control unit performs a process of specifying any of the first to n-th devices based on the designated logical address, and a process of calculating the physical address, When the device corresponding to the logical address is a k-th device (k is 2 or more and n or less), a value corresponding to the total size of the partitions of the first to k-1 devices from the logical address is set. The physical address may be calculated by subtraction.

  Thus, the external device can access the physical address of any device among the plurality of devices by designating the virtual address in the virtual management information 100.

  In the present invention, when the device corresponding to the logical address is the first device, the device control unit may use the logical address as the physical address.

  Thereby, the process of a device control part can be simplified. In addition, the processing of the device control unit can be reduced, and the load on the processing unit that performs the processing of the device control unit can be reduced.

  Further, according to the present invention, the first to nth devices are defined as one device from the partition management information of the first to nth devices (n is an integer equal to or larger than 2) to be transferred via the bus. A virtual management information creating unit for creating virtual management information for recognition; and the first to nth devices are recognized as one device based on the virtual management information, and a logical address of the one device is designated. When the read or write access is requested, device designation information for designating one of the first to n-th devices and the physical corresponding to the logical address based on the virtual management information and the logical address And a device control unit that calculates an address and performs access control on the device.

  In the present invention, the virtual management information creation unit creates the virtual management information by copying the boot information of the management information of any of the first to nth devices into the boot information of the virtual management information. You may make it do.

  In the present invention, the virtual management information creation unit may copy the partition management information of the first device among the first to nth devices to the first partition information of the virtual management information. The virtual management information may be created.

  In the present invention, the virtual management information creation unit performs a process of offsetting a partition start address with respect to partition management information of the second to n-th devices among the first to n-th devices. And the result may be used for the second to n-th partition information of the virtual management information.

  In the present invention, the device control unit performs a process of specifying any of the first to n-th devices based on the designated logical address, and a process of calculating the physical address, When the device corresponding to the logical address is a k-th device (k is 2 or more and n or less), a value corresponding to the total size of the partitions of the first to k-1 devices from the logical address is set. The physical address may be calculated by subtraction.

  In the present invention, when the device corresponding to the logical address is the first device, the device control unit may use the logical address as the physical address.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The embodiments described below do not unduly limit the contents of the present invention described in the claims. Also, not all of the configurations described below are essential constituent requirements of the present invention. In the following drawings, the same reference numerals have the same meaning.

1. Configuration FIG. 1 shows a configuration example of an information processing system according to the present embodiment and an electronic apparatus in which the information processing system is incorporated.

The personal computer PC and the electronic device 10 are connected via a bus 70 (for example, a serial bus such as USB (USB 1.1, USB 2.0, etc.)). Examples of the electronic device 10 include various devices such as a mobile phone, a portable audio device, a portable video device, a digital camera, a digital video camera, a portable information terminal, an IC recorder, and an electronic notebook. The device connected to the electronic device 10 via the serial bus is not limited to the personal computer PC, and may be an electronic device (printer, storage device, etc.) having a host function. The serial bus may be a serial bus other than USB (for example, IEEE 1394), or a multi-channel serial bus. Further, at least a part of the serial bus may be a wireless bus. The bus 70 may not be a serial bus but may be a parallel bus. The electronic apparatus 10 includes an input device 20, a display device 30, a sound device 40, a memory 50, a processing unit 60, a storage drive 80, and a serial interface 90. . The electronic device 10 may have a configuration in which some of these are omitted. For example, a part of the input device 20, the display device 30, and the sound device 40 that are application devices may be omitted, or another application device (for example, an image capturing device such as a CCD) may be provided. When the storage 82 is a removable external medium such as a memory card, the electronic device 10 does not include the storage 82.

  The input device 20 is a device for a user to input various information. Examples of the input device 20 include operation buttons, operation keys, switches, a keyboard, and a mouse.

  The display device 30 is a device for displaying information to the user. Examples of the display device 30 include an LCD (Liquid Crystal Display) or an organic EL display.

  The sound device 40 is a device for outputting sound (voice, music) to a user and inputting (recording) sound. Examples of the sound device 30 include a speaker and a microphone.

  The memory 50 stores a program or temporarily stores data, and is a ROM, RAM, EEPROM (nonvolatile memory capable of electrically rewriting data), or the like. In the present embodiment, a RAM DISK can be constructed on the memory 50 to construct a virtual file system on the RAM.

  The processing unit 60 functions as the information processing system of this embodiment, and controls the entire electronic device 10 and each unit. The processing by the processing unit 60 can be realized by a hardware circuit such as a CPU (processor) and a program (firmware) that operates on the CPU, and this program (processing module) is stored in, for example, the memory 50 (ROM, EEPROM). . However, some or all of these units included in the processing unit 60 may be realized by a dedicated hardware circuit (ASIC).

  The storage drive 80 (storage interface) controls access to the storage 82, and performs control such as accessing the storage 82, reading data from the storage 82, and writing data to the storage 82. The storage 82 stores (records) a file system 84 (file system such as FAT12, FAT16, FAT32, NTFS) of various data (image data, sound data). The storage 82 includes an external medium such as a memory card (multimedia card or memory card) and a built-in medium such as a hard disk.

  Further, FIG. 1 shows only one storage drive 80, but the present invention is not limited to this. A plurality of storage drives 80 may be provided.

  The serial interface 90 is an interface for serial transfer via a serial bus. The serial interface 90 includes a transceiver that is a physical layer circuit, a transfer controller that controls data transfer (packet transfer), a buffer that temporarily stores transfer data (packet buffer), and a buffer that controls access to the buffer. A controller or the like can be included. The connection between the personal computer PC and the electronic device 10 is not limited to the serial bus 70, and may be a parallel bus.

  The virtual management information creation unit 62 of the processing unit 60 is connected to the storage drive 80 and MBR information (Master Boot Record, partition management information in a broad sense) of a RAM disk constructed in the memory 50, for example, as shown in FIG. Virtual management information 100 for recognizing a plurality of devices as one device is created from the MBR information of the storage 82 (for example, a nonvolatile memory card). Thereby, the personal computer PC or the like can recognize the RAM disk and the storage 82 constructed in the memory 50 as one device. That is, it is possible to omit complicated processing necessary for causing a personal computer PC or the like to recognize a plurality of devices.

  The device control unit 64 of the processing unit 60 calculates device designation information for selecting a corresponding device from a plurality of devices based on the virtual management information 100 and a logical sector or logical address designated by an external device or the like. Furthermore, the device control unit 64 calculates the physical sector or physical address of the corresponding device, and performs access control using the physical sector or physical address for the device corresponding to the device designation information.

  In the processing unit 60, the process shown in FIG. 3 is executed. The main 60-1 performs arbitration processing of a plurality of tasks, and the plurality of tasks include a USB control 60-2, a file system control 60-3, a display control 60-4, an input control 60-5, and the like. However, it is not limited to this. For example, the display control 60-4, which is a task for controlling display, and the input control 60-5, which is a task for performing input control, may be omitted. The USB control 60-2 is a task for controlling the USB.

  The file system control 60-3 is a task for controlling access to the file system set in the memory 50 or the storage drive 80, as shown in FIG.

2. Virtual Management Information FIG. 5 is a diagram showing a logical address space of the virtual management information 100. From the virtual management information 100, an external device such as a personal computer PC recognizes a plurality of devices (for example, a RAM disk as device 0 and a memory card as device 1) as one device. Therefore, by specifying a logical address based on the virtual management information 100 from an external device, the RAM disk 50 (hereinafter, the memory 50 is referred to as the RAM disk 50 for the sake of simplicity) and the memory card 82 (hereinafter, the storage 82). Is referred to as a memory card 82 for simplicity of explanation).

  Here, for example, as shown in FIG. 5, it is assumed that logical addresses 10 to 99 are assigned to the RAM disk 50 and logical addresses 100 and later are assigned to the memory card 82. At this time, for example, when there is a request for designating the logical address 100 from the external device, the file system control 60-3 of the processing unit 60 refers to the virtual management information 100 and the logical address 100 is the physical address of the memory card 82. 1 is acquired and control to access the file system of the memory card 82 is performed.

  Further, when there is a request for the external device to specify the logical address 10, the file system control 60-3 acquires the physical address 10 of the RAM disk 50 from the virtual management information 100 and controls to access the RAM disk file system. I do.

  As described above, by assigning physical addresses of a plurality of devices to the virtual management information 100, an external device can access a plurality of devices by designating a logical address of one device.

  FIG. 6 is a diagram illustrating a specific configuration example of the virtual management information 100. FIG. 6 is virtual management information 100 for recognizing, for example, four devices of first to fourth devices (first to nth devices in a broad sense, n is an integer of 2 or more) as one device. . BootStrapLoader (boot information in a broad sense) is set in an area of a predetermined size (446 bytes in FIG. 6) from the logical address 000h. This information may be newly set by the management information creation unit 62, or may be set by copying from the BootStraploader of MBR information of any of the four devices, for example.

  In the area of a predetermined size (16 bytes in FIG. 6) from the logical address 1BEh, the management information 102 of the device 0 (for example, the RAM disk 50) is set as the first partition table (management information in a broad sense). The management information 102 is set by being copied from the MBR information of the device 0 by the management information creation unit 62.

  In the area of a predetermined size (16 bytes in FIG. 6) from the logical address 1CEh, the management information 104 of the device 1 (for example, the memory card 82) is set as the second partition table (management information in a broad sense). This management information 104 is set by the management information creation unit 62 with the MBR information of the device 1 being offset.

  Also in the third and fourth partition tables (management information in a broad sense), the MBR information (for example, management information 106 and 108) of the corresponding device is set with a predetermined offset, as in the second partition table. The

  FIG. 7 is a diagram showing details of the management information 102 to 108. Each management information 102 to 108 is composed of, for example, 16 bytes, and in order from the top, a boot flag BF (for example, 1 byte), a start address CHS1 (for example, 3 bytes), a partition type (for example, 1 byte), and an end address CHS2 (for example, 3 bytes). Byte), start address LBA1 (for example, 4 bytes), and area size LBA2 (for example, 4 bytes).

  The boot flag BF is information for setting active / inactive booting of the partition (device corresponding to the management information). The start address CHS1 and the end address CHS2 are information indicating a start address or an end address in the virtual management information 100 of a partition (device corresponding to management information) in the CHS (Cylinder Head Sector) method.

  The start address LBA1 is information indicating the start address of the logical block in the virtual management information 100 of the partition (device corresponding to the management information), and the area size LBA2 is the logical address in the virtual management information 100 of the partition (device corresponding to the management information). This is information indicating the size of the block.

  In the present embodiment, each piece of management information 102 to 108 is configured to support both the CHS method and the LBA method.

3. Virtual Management Information Creation Unit FIG. 8 is a diagram showing a creation flow of the virtual management information 100. As shown in step S1, the virtual management information creation unit 62 first acquires MBR information (management information in a broad sense) of the RAM disk 50 (first device in a broad sense). Then, as shown in step S2, MBR information (management information in a broad sense) of the memory card 82 (second device in a broad sense) is acquired. In step S3, virtual management information 100 is created based on the MBR information acquired in steps S1 and S2.

  Note that the order of step S1 and step S2 may be reversed.

  FIG. 9 is a diagram illustrating an example of the virtual management information 100 when the virtual management information 100 is created based on LBA partition information among the MBR information acquired by the virtual management information creation unit 62, for example. As shown in FIG. 9, the physical sector of the RAM disk 50 is, for example, 1 to (number of sectors of the RAM disk 50 −1), and the physical sector of the memory card 82 is, for example, 1 to (number of sectors of the memory card 82 −1. ).

  Note that the number of sectors of the RAM disk 50 and the number of sectors of the memory card 82 are numbers obtained from each MBR information.

  The virtual management information creating unit 62 creates the virtual management information 100 using the MBR information of the RAM disk 50 and the memory card 82. A single device when the external device is recognized as a single device by the virtual management information 100 is referred to as a virtual device 110. The virtual management information 100 corresponds to the MBR information of the virtual device 110. The virtual management information 100 corresponds to the virtual sector 0 of the virtual device 110.

  The virtual management information creating unit 62 copies the MBR information of the RAM disk 50 and uses it as a first partition table (management information in a broad sense) of the virtual management information 100. Specifically, virtual sector 1 corresponds to physical sector 1 of RAM disk 50, and virtual sector (number of sectors of RAM disk 50-1) becomes physical sector of RAM disk 50 (number of sectors of RAM disk 50-1). Correspond.

  Further, the virtual management information creating unit 62 performs processing for offsetting the MBR information of the memory card 82, and creates a second partition table (management information in a broad sense) of the virtual management information 100 using the result. Specifically, the virtual sector (the number of sectors of the RAM disk 50) corresponds to the physical sector 1 of the memory card 82, and the virtual sector (the number of sectors of the RAM disk 50 + the number of sectors of the memory card 82) is the memory card 82. Corresponds to the number of physical sectors (the number of sectors of the memory card 82). Here, the virtual sector (the number of sectors of the RAM disk 50) is obtained by offsetting the physical sector 1 of the memory card 82 (the number of sectors of the RAM disk 50 minus 1). Similarly, the virtual sector (the number of sectors of the RAM disk 50 + the number of sectors of the memory card 82−2) is offset to the physical sector of the memory card 82 (the number of sectors of the memory card 82−1) (the number of sectors of the RAM disk 50− 1).

4). Access Control FIG. 10 shows a flow of access control for each device when a request for specifying the logical sector x (virtual sector x) of the virtual device 110 set as shown in FIG. 9 is sent from an external device. FIG.

  First, in step S11, it is determined whether or not the logical sector x is 0. At this time, if the logical sector x is 0, the processing shown in step 12 is performed. Step 12 is processing for accessing data stored as the virtual management information 100. Thereby, the external device or the like can acquire information such as the first to fourth partition tables of the virtual management information 100, for example. Further, the virtual management information 100 may be rewritten from an external device or the like.

  On the other hand, if the logical sector x is not 0, the process of step 13 is performed. In step 13, the size comparison between the logical sector x and the number of sectors of the RAM disk 50 is performed. If the logical sector x is smaller than the number of sectors of the RAM disk 50, a process of accessing the physical sector x on the RAM disk 50 is performed as shown in step 14. In this case, the value of the logical sector x is used as it is as the physical sector x.

  If the logical sector x is larger than the number of sectors in the RAM disk 50 in step 13, the process of calculating the physical sector on the memory card 82 from the logical sector x and the number of sectors in the RAM disk 50 as shown in step 15; Then, a process of accessing the calculated physical sector on the memory card 82 is performed. Specifically, in step 15, the logical sector x− (number of sectors of the RAM disk 50) +1 is calculated as a physical sector on the memory card 82, and the physical sector (logical sector x− (RAM disk 50) on the memory card 82 is calculated. The process of accessing 50 sectors + 1) is performed.

  The RAM disk 50 and the memory card 82 can be accessed by the processing as described above. The access control process shown in FIG. 10 is performed by the device control unit 64 of the processing unit 60. The device control unit 64 may be incorporated, for example, in the file system control 60-3 of FIG. 3, or may be provided as a module for performing access control separately.

5. Comparison and Effect with Comparative Example FIG. 11 is a diagram illustrating an electronic apparatus 11 of a comparative example that causes an external apparatus (for example, a personal computer PC) to recognize a plurality of devices as a plurality of devices.

  In the case of the comparative example, in order to make an external device recognize a plurality of devices, firmware with complicated processing and a processing device (for example, a CPU) that processes the firmware are necessary. Therefore, the circuit scale of the electronic device 11 also increases, and it is difficult to mount the electronic device 11 on a small electronic device such as a portable electronic device.

  Furthermore, as shown in FIG. 11, for example, two devices are recognized by an external device, so that arbitration processing such as which device is accessed from the external device becomes complicated, and the transfer rate of the interface with the external device is high. If so, it is required that the processing speed of the processing apparatus in the electronic device 11 is also high. For example, a card reader or the like that is connected to a personal computer PC can be commercialized as a highly functional electronic device 11 at some cost of the electronic device 11.

  However, it is practically difficult to mount the electronic device 11 on a small electronic device due to problems such as a large circuit scale and power consumption due to high-speed processing. In that case, a method of simplifying the firmware of the electronic device 11 and selecting one of the two devices and causing the external device to recognize the device can be considered. If it is this, the capability of the processing apparatus of the electronic device 11 can also be lowered | hung and it becomes possible to mount in a small electronic device. However, this method is inconvenient because it is necessary to switch the device to be recognized by some method.

  In contrast, in the present application, for example, by using the virtual management information 100 as illustrated in FIG. 1, it is possible to cause an external device to recognize a plurality of devices as a single device. Can be recognized.

  In the embodiment of the present application, it is possible to recognize a plurality of devices as described above only by mounting a virtual management information creating unit 62 (for example, firmware) that creates the virtual management information 100 in the electronic device 10. Since the processing of the virtual management information creating unit 62 is very light in terms of firmware, firmware that is significantly lighter than the electronic device 11 of the comparative example can be applied to the electronic device 10. For this reason, the capability required of the processing device required for the processing unit 60 is also reduced, and the circuit scale and power consumption can be reduced.

  Furthermore, once the virtual management information 100 is created, the virtual management information creation unit 62 does not have to create the virtual management information 100 until the storage 82 is changed (such as replacement of storage media). Also in this point, the electronic device 10 according to the embodiment is advantageous in reducing power consumption as compared with the electronic device 11.

  Further, in the present embodiment, when a plurality of devices are mounted on the electronic device 10, the plurality of devices can be easily recognized by an external device by creating as many partitions of the virtual management information 100 as the number of devices. . That is, the design of firmware for control is simplified and the design cost can be reduced.

  Further, if the number of devices increases, the firmware becomes more complicated in the configuration as in the comparative example. If the firmware becomes complicated, the processing capability required for the processing apparatus increases, which is very disadvantageous in terms of mounting in a small electronic device.

  However, in the present application, the number of devices can be easily accommodated. Therefore, even if the number of devices increases, the firmware is very light compared to the comparative example, so the processing capability required for the processing apparatus does not increase so much. That is, even when the number of devices increases, the present embodiment can reduce the increase in circuit scale and power consumption due to the processing apparatus, and is therefore advantageous in mounting in a small electronic device as compared with the comparative example.

  As described above, the embodiments of the present invention have been described in detail. However, those skilled in the art can easily understand that many modifications can be made without departing from the novel matters and effects of the present invention. . Accordingly, all such modifications are intended to be included in the scope of the present invention. For example, a term described with a different term having a broader meaning or the same meaning at least once in the specification or the drawings can be replaced with the different term anywhere in the specification or the drawings.

1 is a configuration example of an electronic device according to an embodiment. FIG. 3 is a diagram showing a connection between an electronic device and an external device according to the embodiment. The structural example of the task processed by the process part which concerns on this embodiment. Configuration example of file system control. 4 is a configuration example of a logical address by virtual management information according to the present embodiment. 3 is a configuration example of virtual management information according to the present embodiment. The figure which shows an example of the detail of a part of virtual management information which concerns on this embodiment. The figure which shows an example of the creation flow of the virtual management information which concerns on this embodiment. The figure which shows the example of a response | compatibility with the virtual management information which concerns on this embodiment, and each device. The figure which shows an example of a process of the device control part which concerns on this embodiment. FIG. 6 is a view showing an electronic apparatus of a comparative example according to the embodiment.

Explanation of symbols

10 electronic devices, 50 RAM disks, 62 virtual management information creation unit,
64 device control unit, 82 memory card, 100 virtual management information

Claims (12)

First to nth devices (n is an integer equal to or greater than 2) that are targets of data transfer via the bus;
A virtual management information creating unit for creating virtual management information for recognizing the first to nth devices as one device from the partition management information of the first to nth devices;
When the first to nth devices are recognized as one device based on the virtual management information, and a read or write access is requested by specifying a logical address of the one device,
Based on the virtual management information and the logical address, device designation information for designating any of the first to n-th devices and a physical address corresponding to the logical address are calculated, and the first to n-th devices are calculated. A device control unit for controlling access to at least one of the devices;
A data control system comprising: In claim 1,
The virtual management information creation unit
A data control system that creates the virtual management information by copying the boot information of the management information of any of the first to nth devices into the boot information of the virtual management information. In claim 1 or 2,
The virtual management information creation unit
A data control system for creating the virtual management information by copying the partition management information of the first device among the first to n-th devices to the first partition information of the virtual management information . In claim 3,
The virtual management information creation unit
The partition management information of the second to n-th devices among the first to n-th devices is subjected to processing for offsetting the start address of the partition, and the result is stored in the second to second virtual management information. A data control system used for n-th partition information. In any one of Claims 1 thru | or 4,
The device controller is
Based on the specified logical address, a process for specifying one of the first to n-th devices and a process for calculating the physical address are performed.
When the device corresponding to the logical address is a k-th device (k is 2 or more and n or less), a value corresponding to the total size of the partitions of the first to k-1 devices from the logical address is set. A data control system, wherein the physical address is calculated by subtraction. In claim 5,
The device controller is
When the device corresponding to the logical address is the first device, the logical address is used as the physical address. Virtual management for recognizing the first to n-th devices as one device from the partition management information of the first to n-th (n is an integer of 2 or more) devices to be transferred via the bus A virtual management information creation unit for creating information;
When the first to nth devices are recognized as one device based on the virtual management information, and a read or write access is requested by specifying a logical address of the one device,
A device that performs device access control by calculating device designation information for designating any of the first to nth devices and a physical address corresponding to the logical address based on the virtual management information and the logical address. A control unit;
The program characterized by including. In claim 7,
The virtual management information creation unit
A program for creating virtual management information by copying boot information of management information of any of the first to nth devices into boot information of the virtual management information. In claim 7 or 8,
The virtual management information creation unit
A program for creating the virtual management information by copying the partition management information of the first device among the first to n-th devices to the first partition information of the virtual management information. In claim 9,
The virtual management information creation unit
The partition management information of the second to n-th devices among the first to n-th devices is subjected to processing for offsetting the start address of the partition, and the result is stored in the second to second virtual management information. A program using the nth partition information. In any of claims 7 to 10,
The device controller is
Based on the specified logical address, a process for specifying one of the first to n-th devices and a process for calculating the physical address are performed.
When the device corresponding to the logical address is a k-th device (k is 2 or more and n or less), a value corresponding to the total size of the partitions of the first to k-1 devices from the logical address is set. A program characterized in that the physical address is calculated by subtraction. In claim 11,
The device controller is
When the device corresponding to the logical address is the first device, the program uses the logical address as the physical address.

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