JP2006133889A - Method for updating program, program and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for updating a program incorporated in a terminal, whose memory capacity is limited and on which an MMU-adaptable OS is mounted, by using difference data received by a communication means, and to provide the program, device and terminal therefor. <P>SOLUTION: The difference data for updating the program are received and stored in a memory in a first operation mode where memory protection by an MMU is operated, and the operation mode is switched to a second operation mode where memory protection by the MMU is not operated, and the stored difference data are acquired so that the program can be updated by using the difference data. When the received difference data are stored in the memory, the conversion of a logical address and a physical address space is operated by the MMP, and the information on address conversion for the storage region of the difference data isheld, thereby accessing the difference data in the second operation mode. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method, a program, and a terminal device for updating a program built in a terminal device using difference data received by a communication means, and particularly has a limited memory capacity and is equipped with an MMU-compatible OS. The present invention relates to a method, a program, and a terminal device for updating a program in a portable terminal device.

  The software built in portable terminal devices equipped with communication means such as mobile phones and personal digital assistants (PDAs, etc.) has become large-scale, and even after product shipment, the outside of the terminal has been expanded in order to improve programs and deal with problems. These programs may be updated by supplying update data.

  Conventionally, such data has been supplied via wired communication at stores that provide support, but in recent years in order to expedite the resolution of serious problems and to reduce support costs for renewal work. In addition, data is supplied via wireless communication. When data is supplied by wireless communication in this way, the size of the data to be supplied is reduced because the bandwidth of the wireless link is small and the portable terminal device has a smaller memory capacity than a general-purpose computer such as a personal computer. It is required to be as small as possible.

  In Patent Document 1, in order to reduce the size of the supply data, on the data transmission side, a difference obtained by comparing the version before update and the version after update of the program in the terminal device is extracted. Only the difference data is transmitted to the terminal device, and the terminal device restores the updated data from the data in the device (program to be updated) and the received difference data, and the program to be updated by this updated data A method of updating a program by rewriting the storage area is disclosed.

  However, in a portable terminal device, the memory capacity may be so small that it is not possible to secure a work area sufficient to restore all the data to be updated, that is, the updated data used for rewriting from the difference data.

  As a method for coping with this problem, Patent Document 2 discloses that the target program is divided into a plurality of areas, and on the data transmission side, difference data is extracted for each area, and all the difference data is collected. The terminal device performs the restoration of the updated data for each differential data for each area, and after updating each area without waiting for the restored data for all areas to be restored. There has been disclosed a method for updating a program by writing data in the storage area of the update target program without having to simultaneously hold updated data in all areas. Patent Document 3 discloses a method of reducing the difference data extracted for each region in the method disclosed in Patent Document 2.

  Non-Patent Document 1 discloses “Block-Move Algorithm”, which is a basic algorithm for extracting difference data between corresponding regions of two programs as constituent elements in Patent Document 1, Patent Document 2, and Patent Document 3. Has been.

  On the other hand, as another method for suppressing the influence caused by the malfunction of the software of the mobile terminal which is becoming large-scale, the memory protection is performed by using the MMU (memory management unit) for the OS (operating system) operating on the terminal device. A method is known (hereinafter, such an OS is referred to as an MMU-compatible OS). In an OS that does not support MMU, a failure of a specific application affects other applications or the entire system, whereas an OS that supports MMU has an advantage that such an effect can be localized and reduced. For this reason, the OS of mobile phones is shifting from an OS that does not support MMU, such as μITRON, to an OS that supports MMU, such as Linux and Symbian.

JP-A-8-255104. Japanese Patent Application Laid-Open No. 2004-234503. JP 2004-227520 A. Walter F. Tichy, The String-to-String Correction Problem with Block Moves, ACM Transaction on Computing Systems, Nov.1984 (Vol.2, No.4), pp.309-321

  In general, the memory of the portable terminal device as described above is composed of a rewritable volatile memory such as a RAM and a rewritable nonvolatile memory such as a flash ROM. The former is a work area and / or The latter is used as a temporary data storage area, and the latter is used as a storage area for programs and / or permanent data composed of instruction codes and initialization data used by the instruction codes. In mobile phones, etc., we try to reduce the memory capacity as much as possible in order to reduce production costs, so the area for instruction codes and constant data is not copied to RAM, but is rewritable and non-volatile such as flash ROM. Often read directly from the memory.

  On the other hand, in an MMU-compatible OS, since the program and constant data areas are usually protected by the MMU, it is not possible to rewrite the program in the memory while the memory management by the MMU is being performed. Is possible. Patent Documents 1 to 3 and Non-Patent Document 1 do not specifically mention a method for updating a program in such a terminal device equipped with an MMU-compatible OS.

  The present invention has been made in view of such circumstances, has a limited memory capacity, and uses differential data received by communication means for a program built in a terminal device equipped with an MMU-compatible OS. It is an object of the present invention to provide a method, a program, and a terminal device for updating the program.

  As a result of diligent research in view of the above problem, the present inventor, after receiving the differential data for program update in the first operation mode in which memory protection is performed by the MMU and storing it in the memory, changes the operation mode to the MMU. It was conceived to switch to the second operation mode in which the memory protection is not performed, to acquire the stored difference data, and to update the program using this. Here, when the received difference data is stored in the memory, the logical address and the physical address space are converted by the MMU, but information regarding the address conversion for the storage area of the difference data is held. This makes it possible to access the difference data in the second operation mode later.

  That is, the present invention is a method for updating a program of a terminal device using difference data for program update, and includes a difference data acquisition step for acquiring the difference data and a first operation in which memory management is performed by the OS. In the mode, a difference data storage step for storing the difference data in a memory, information on an arrangement of the difference data in the memory, a difference data arrangement information storage step for storing in the memory, and contents stored in the memory An operation mode switching step for switching from the first operation mode to a second operation mode in which memory management by the OS is not performed is held and stored in the memory in the second operation mode. Difference for acquiring the difference data from the memory based on the difference data arrangement information And over data restoration step, using the difference data, a program updating step of updating of the program, there is provided a method comprising.

  In the program update method of the present invention, the memory is configured as a file system that can be used in the first operation mode and the second operation mode, and in the differential data storage step, a file on the file system is configured. In the difference data arrangement information storage step, information specifying the file storing the difference data is acquired and stored as the difference data arrangement information, and in the difference data restoration step, The difference data is acquired by reading a file storing the difference data based on the difference data arrangement information.

  In the program update method of the present invention, the memory stores a dummy file having a size equal to or larger than a maximum size that can be taken by the difference data. In the difference data acquisition step, the acquired difference data is overwritten on the dummy file. It is characterized in that the processing is performed.

  In the program update method of the present invention, in the differential data storage step, the differential data is stored in an area on one or more physical address spaces in the memory, and in the differential data arrangement information storage step, the physical address of the area is stored. It acquires and stores the position and size in space and information related to the storage order of the difference data.

  The program update method of the present invention further includes a step of reducing the number of areas on the physical address space required for storing the differential data in the memory before executing the differential data storage step. It is characterized by that. Specifically, before executing the difference data storing step, a step unnecessary for the program update process is stopped and a memory area used for the step is released, or a step of restarting the OS is performed. be able to.

  In the program update method of the present invention, in the differential data acquisition step, differential data for program update is acquired from the outside of the terminal device by communication means.

  In the program update method of the present invention, the memory management by the OS is realized by address conversion between a logical address and a physical address by the MMU.

  The present invention also provides a program for executing a program update process of a terminal device using any one of the program update methods described above. Furthermore, a recording medium recording such a program is provided.

  The present invention is also a terminal device including a program, a memory that stores the program and update data for the program, a memory management unit that manages the memory by the OS, and obtains differential data for program update Differential data acquisition means, program update means for updating the program using the difference data, a first operation mode in which memory management is performed by the OS while retaining the contents stored in the memory, An operation mode switching unit that switches an operation mode between a second operation mode in which memory management by the OS is not performed, and the difference data acquired by the difference data acquisition unit in the first operation mode Storing in the memory and acquiring information about the arrangement of the difference data in the memory After the storage, in the second operation mode, the terminal acquires the difference data from the memory based on the information on the arrangement of the difference data stored in the memory, and updates the program using the difference data A device is provided.

  In the terminal device of the present invention, the memory is configured as a file system that can be used in the first operation mode and the second operation mode, and the difference data is stored in a file on the file system, The arrangement information of the difference data is information for identifying a file storing the difference data. Based on the difference data arrangement information, the difference data is acquired by reading the file storing the difference data. Features.

  In the terminal device according to the present invention, the memory stores a dummy file having a size equal to or larger than a maximum size that the difference data can take, and the difference data acquisition unit overwrites the acquired difference data on the dummy file. It is characterized by performing processing.

  In the terminal device of the present invention, the difference data is stored in one or more areas on the physical address space in the memory, and when the difference data arrangement information is stored in the memory, the difference data on the physical address space of the area is stored. The position and size, and information regarding the storage order of the difference data are acquired and stored.

  The terminal device of the present invention further includes area reduction means for reducing the number of areas in the physical address space necessary for storing the difference data in the memory before storing the difference data. Features.

  In the terminal device according to the present invention, the area reduction means stops the work unnecessary for the program update process and releases the memory area used for it. Alternatively, the OS is restarted.

  In the terminal device according to the present invention, the difference data acquisition unit acquires the difference data for program update from the outside of the terminal device by a communication unit.

  In the terminal device according to the present invention, the memory management means realizes memory management by address conversion between a logical address and a physical address by the MMU.

  The present invention also provides a portable terminal including any one of the terminal devices described above.

  As described above, according to the method, program, and apparatus for updating the program of the present invention, the memory capacity is limited, and the program built in the terminal device equipped with the MMU-compatible OS is communicated. It becomes possible to update using the difference data received by the means.

  The best mode for carrying out a method, a program, and an apparatus for updating a program according to the present invention will be described below in detail with reference to the accompanying drawings. 1 to 7 are diagrams illustrating embodiments of the present invention. In these drawings, the same reference numerals denote the same components, and the basic configuration and operation are the same. To do.

Hardware Configuration of Terminal Device FIG. 1 is a block diagram schematically showing a hardware configuration of a terminal device including a program to be updated in this embodiment. In FIG. 1, the terminal device includes a program execution processing unit 11, a storage unit 12, a wireless communication unit 13, and an antenna 14. The storage unit 12 includes a RAM 121, a program flash ROM 122, and a data flash ROM 123. The program execution processing unit 11 includes a CPU core 111 that executes a program built in the program flash ROM 122, and an MMU that performs processing for converting a logical address included in the program to be executed into a physical address of a memory in the storage unit 12. (Memory management unit) 112.

  The terminal device shown in FIG. 1 is portable, and the memory capacity is kept as small as possible in order to reduce production costs and power consumption. It is assumed that no secondary storage device is installed. The above-mentioned flash ROM is a rewritable nonvolatile memory and consumes less power than a hard disk. In the present embodiment, the program to be updated is stored in the program flash ROM 122, and this program is not copied to the RAM 121 at the time of execution in order to increase the memory usage efficiency. Thus, the program is read directly from the program flash ROM 122 and executed. Since the NOR type flash memory can be directly read and accessed by designating an address, such a utilization form is possible. However, this is not related to the essence of the present invention, and the present invention itself can be applied to a NAND-type program flash ROM (the program to be executed needs to be copied to the RAM once).

  Further, the terminal device shown in FIG. 1 is configured to be able to reset the CPU core 111 while retaining the stored contents of the RAM 121. For example, if the RAM is an SRAM, no special configuration is required, and the stored contents of the RAM are retained even after the CPU core is reset. If the RAM is a DRAM, the Self Refresh mode (in recent DRAMs) Many of them are equipped with this mode), and if reset is performed, the stored contents of the RAM are retained. In addition, when both reading and writing are mixed in the command to the flash ROM, the reading speed is usually lower than when only reading is performed. Program and data flash ROMs are provided to prevent the speed from dropping.

  1 may be provided with wired communication means such as a network interface card in place of the wireless communication unit 13 and the antenna 14.

Functional Configuration of Terminal Device FIG. 2 is a functional block diagram showing a functional configuration based on the processing contents of the terminal device shown in FIG. In FIG. 2, the terminal device includes a program execution unit 21, a storage unit 22, and a difference data reception unit 23. The program execution means 21 includes a program execution means 211 in a first operation mode (hereinafter referred to as “operation mode 1”), a program execution means 212 in a second operation mode (hereinafter referred to as “operation mode 2”), An operation mode switching / restarting execution unit 213 and an address conversion unit 214 are included. The storage unit 22 includes a first program 221 executed by the program execution unit 211 according to the operation mode 1, a second program 222 executed by the program execution unit 212 according to the operation mode 2, and the difference data received by the difference data reception unit. 223 and difference data arrangement information 224 generated by the program execution means in the operation mode 1 are stored.

  Here, the program execution unit 21 is a function corresponding to the program execution processing unit 11, the storage unit 22 is a function corresponding to the storage unit 12, and the difference data receiving unit is a function corresponding to the wireless communication unit 13. . That is, the first program 221 and the second program 222 included in the storage unit 22 are stored in the program flash ROM 122 of the storage unit 12, and the difference data 223 and the difference data arrangement information 224 are stored in the RAM 121 or It is stored in the data flash ROM 123.

  Data read / write from / to the data flash ROM 123 is normally performed via a file system. However, an area (reserved area) to be used for a specific purpose is determined and read / write is not performed via the file system. It is also possible to do this. Therefore, in the terminal device of this embodiment, most of the data flash ROM is read and written through a file system (hereinafter referred to as “flash file system”), and a small number of specific data is read and written in a reserved area. .

  The first program 221 is a program to be updated, and is executed by the program execution unit 211 in the operation mode 1. The second program 222 is a program that performs processing for updating the first program 221 and is executed by the program execution means 212 in the operation mode 2. Since the second program 222 cannot be updated, it is preferable that the second program 222 has a simple configuration having only a function related to the update process in order to reduce the possibility of malfunction. For this reason, most of the program codes incorporated in the terminal device are configured to be included in the first program 221. As will be described later, differential data reception processing using differential data reception means is also performed by the first program.

  The first program 221 includes an OS (operating system) program code that performs memory protection using the MMU 112, and the program execution means 211 in the operation mode 1 performs address conversion using the address conversion means 214 and Perform memory protection. On the other hand, the second program 222 does not include such a program code, and the program execution unit 212 in the operation mode 2 does not use the function of the address conversion unit 214.

  The operation mode switching / restarting execution means 213 switches the subject executing the program between the program execution means according to the operation mode 1 and the program execution means according to the operation mode 2. In the terminal device according to the present embodiment, when switching is performed by designating the next operation mode, a program that operates in the designated operation mode is executed from the beginning. Therefore, if the same operation mode as the current operation mode is designated as the next operation mode, the program is restarted. Therefore, the operation mode switching function and the program restart function are performed by the operation mode switching / restart execution means 213. Will be provided.

  The address conversion unit 214 performs memory protection by performing conversion from a logical address to a physical address using the MMU 112. Address conversion is performed in units of pages. For example, assuming that the address is 32 bits, the page size is 4K, the upper 20 bits of the logical address represent the logical page number, and the upper 20 bits of the physical address represent the physical page number, the address conversion means performs the page table (logical Is a correspondence table of page numbers and physical page numbers, and is normally held in the RAM), by replacing the logical page number of the logical address with the physical page number, the logical address in the storage unit 12 Can be converted to

  FIG. 3 is a schematic diagram illustrating the correspondence between the logical address space and the physical address space when the address conversion unit 214 performs address conversion. The address conversion means 214 can realize memory protection by prohibiting the authority to access a specific page or making it read-only in the process of performing such address conversion. For example, an area on the logical address space in which the program is stored is set to read-only (write-inhibited), or from the application 1 program that is a part of the first program, it is also a part of the first program. Access to the data of the application 2 can be set to be prohibited. Some MMUs have only such a memory protection function, but generally they are often used together with an address translation function.

  In the terminal device of this embodiment, when the execution of the first program 221 is started, the address translation by the MMU is enabled by the OS startup process in the initial stage, and the first program 221 uses a logical address. On the other hand, since the second program 222 does not use the address conversion function by the address conversion means, the physical address in the storage unit 12 is used as the address used by the second program 222.

Program Update Processing by Terminal Device Next, a procedure for performing the program update processing in the terminal device of the present embodiment described above will be described with reference to the flowcharts of FIGS. In the following, for the sake of specific explanation, in the hardware configuration of the terminal device shown in FIG. 1, the size of the RAM 121 is 16 Mbytes, the size of the program flash ROM 122 is 32 Mbytes, and the size of the data flash ROM 123 is 32 Mbytes. Yes. In addition, the maximum size of the difference data is 4 Mbytes.

  FIG. 4 is a flowchart showing the flow of the first half of the program update process executed by the program execution unit 211 in the operation mode 1. The operation mode 1 is a state in which the terminal device is operating normally, and the function of performing address translation / memory protection using the MMU 112 by the address translation means is working. When the program update process is started in this state, the process of the flowchart of FIG. 4 is started.

  First, a difference data receiving step (S41) is executed. In this step, the difference data receiving unit 23 receives the difference data using the wireless communication unit 13 and stores it in the storage unit 22. The storage destination here is a file on the file system (flash file system) of the data flash ROM 123 or a reserved area (or can be a working area of the RAM). Next, a difference data arrangement information acquisition step (S42) is executed, and difference data arrangement information is acquired from the difference data stored in step S41. Here, when the difference data is stored in the file on the flash file system in step S41, the file name in which the difference data is stored is acquired as the difference data arrangement information. On the other hand, when the difference data is stored in the reserved area of the flash ROM (or the work area of the RAM) in step S41, the logical address of the reserved area and information related to the arrangement of the physical pages are acquired as the difference data arrangement information. Will be. The contents of the difference data arrangement information will be described in detail later (* 1).

  The acquired difference data arrangement information is stored in the reserved area of the data flash ROM 123. Next, an operation mode switching step is performed (S43). In this step, the operation mode switching / restart execution means 213 switches from the operation mode 1 to the operation mode 2. The actual switching process is performed by storing the next operation mode in the reserved area of the data flash ROM 123 and then resetting the CPU core 111. This reset is performed while holding the difference data stored in step S41 and the difference data arrangement information stored in S42. Thereafter, the reset processing routine reads the next operation mode in the reserved area and performs the start-up processing in the designated operation mode. Here, since operation mode 2 designated as the next operation mode in step S43 is activated, switching from operation mode 1 to operation mode 2 occurs. Thus, the first half of the program update process executed by the program execution unit 211 in the operation mode 1 is completed.

  FIG. 5 is a flowchart showing the flow of the latter half of the program update process executed by the program execution means 212 in the operation mode 2. First, a differential data restoration step (S51) is executed. In this step, the difference data received in step S41 is restored using the difference data arrangement information acquired in step S42. Subsequently, an updated data generation step (S52) for generating updated data for the predetermined part from the restored difference data and the pre-update data which is the predetermined part of the first program is executed. Further, a rewriting step (S53) is executed in which the corresponding part of the first program is rewritten using the updated data. Thereafter, it is determined whether or not the differential data restored in step S51 remains (S54). If the differential data remains, the processing from step S52 is repeated for the remaining differential data. The second half of the program update process executed by the program execution means 212 is completed.

  In step S54, when the restored differential data remains, on the transmission side of the program update differential data, the updated first program is compared and updated for each of the plurality of divided areas. This is a case where the difference data for a plurality of areas is acquired in the terminal device because the difference data of only the area is extracted and transmitted to the terminal device. In such a case, the updated data generation step (S52) and the rewrite step (S53) are repeatedly executed for each area until all the difference data is used.

  The program update process is all completed. By the way, in FIG. 4, the difference data receiving step is included in the first program executed in the operation mode 1 in order to keep the function of the second program executed in the operation mode 2 within a small range. This is because by including it in the first program, the advantage that advanced and widely used communication functions such as HTTP and HTTPS (SSL) supported by the OS can be used. In fact, it is difficult to express these advanced communication functions in the small program capacity of the second program.

  FIG. 6 is a flowchart showing details of the processing in the differential data restoration step (S51) of FIG. As described above, since the contents of the difference data arrangement information differ depending on the storage destination, when restoring the difference data, it is first determined whether or not the difference data arrangement information is a file name (S61). If the difference data arrangement information is a file name, the file on the flash ROM file system (flash file system) can be read to obtain difference data (S62). If the difference data placement information is not the file name but the logical address of the reserved area in the flash ROM and the physical page sequence, the original differential data is restored by reading the differential data from the physical page according to the sequence. (S63).

  In step S63, when the difference data is read from the reserved area of the flash ROM, an additional work area having the same size as the difference data is required. In order to avoid this, the original difference data may be restored by performing a process of rearranging the difference data information in units of pages in the reserved area of the flash ROM according to the difference data arrangement information. For example, if the difference data arrangement information is read out to the memory (4 Kbytes) and the pages are sorted using it as a key, the required additional work area can be reduced.

  As described above, the basic procedure of the program update process in the terminal device according to the present embodiment has been described with reference to FIGS. 4 to 6. In the terminal device having a limited memory capacity, the difference data is stored in step S41 in FIG. When received, there is a possibility that an area for temporarily storing the data cannot be secured on the RAM or the flash file system. In the program update process of the present embodiment described above, since the terminal device receives all the difference data and stores it in the storage means and then switches from the operation mode 1 to the operation mode 2, at least the maximum size of the difference data ( In the above, it is necessary to secure an area corresponding to 4 Mbytes) on the RAM or the flash file system.

  As a countermeasure, when all the difference data is stored in a file of the flash file system, for example, a dummy file of 4 Mbytes is created in the flash file system in advance, and the received difference data is overwritten on the file. That's fine. Alternatively, even if a dummy file is not created, a file that can be erased may be erased to create a free area before the program update process is performed. The latter method is effective when it is known in advance that such a file (such as a low-importance file or a file that can be recovered from backup later) has a predetermined size or more. If it is not known in advance, the user may be prompted to delete unnecessary files through the user interface to create a necessary free area.

  Alternatively, in order to secure a work area for storing difference data on the RAM, a work area used for other purposes can be released and used for storing difference data. In order to perform such release processing, processes other than the program update processing may be individually stopped, and the work areas used by them may be released. Alternatively, the program update process may be continued after the OS operating in the operation mode 1 is once restarted. For example, the same processing as step S43 may be performed by setting the next operation mode to operation mode 1.

  FIG. 7 is a flowchart showing a flow of processing for the work area performed in the difference data receiving step (S41 in FIG. 4) when the work area for storing the difference data cannot be secured on the RAM. First, the first program operating in the operation mode 1 stores the received difference data in a file on the flash file system (S71). As described above, if a dummy file having the same size as the maximum size of the difference data is created in advance on the flash file system, this process can be executed reliably. Note that in the MMU-compatible OS startup process, the RAM is usually initialized, so that the difference data cannot be stored on the RAM in S71. Subsequently, in order to secure a work area on the RAM, the OS on which the first program is running is restarted (S72). After the OS is restarted, a work area for storing the received difference data is secured on the RAM (S73), and the difference data stored in the file on the flash file system is read into the work area (S74). With the above processing, the difference data receiving step (S41 in FIG. 4) is normally executed.

  In the process shown in FIG. 7, the program update process cannot be executed unless a necessary work area can be secured on the RAM in step S73. However, since the work area that can be secured immediately after the restart has reproducibility according to the version of the program, it is possible to know whether or not the maximum size of the difference data can be secured by a preliminary investigation. Further, the OS that operates after restarting in step S72 may be the same OS as that at the time of execution of step S71. However, the program that runs on the OS after the restart is different from that at the time of execution of step S71. It can be kept to the minimum necessary for the processing after S73. Specifically, the file reading function is necessary even after step S73, but the difference data receiving function used in step S71 is not necessary. Thus, in step S73 after the OS is restarted, it can be expected that a larger work area can be ensured than in the execution of step S71.

  In addition, immediately after the OS is restarted, it is shortly after the initialization of the RAM as described above, so it has not been used on the RAM since the initialization until immediately before the work area on the RAM is secured. When physical pages remain, it can be expected that many continuous physical pages are included in the work area. Generally, when physical pages are continuous, the size of effective differential data arrangement information can be reduced. This is because the smaller the number of continuous areas, the smaller the size of the difference data arrangement information. When the entire work area is composed of only one area composed of continuous physical pages, the difference data arrangement information This is because the size of is minimized. Since the actual size of the difference data arrangement information is reproducible according to the version of the program, the size of the difference data arrangement information can be known by prior investigation, and the size of the reserved area can be reduced. .

  If it is not immediately after startup, physical page allocation and release are repeated by the OS, so whether or not a large number of continuous physical pages are allocated in the work area depends on the management algorithm of free pages, but in general there are many You cannot expect to be assigned. Depending on the OS, an API for securing a work area in which physical pages are continuous may be provided to secure a buffer for DMA processing, and such an API may be created by modifying the OS. However, since the size of the difference data arrangement information when restarting can be known in advance, restarting is easier if the same effect can be expected.

  In the processing of steps S71 to S74, the restart is performed after the difference data is received. However, after the restart is performed before the difference data is received and the work area is secured on the RAM before the data is received. The difference data may be received and stored. If it can be determined that there is no shortage of RAM even if differential data reception processing is performed with a work area secured, this processing procedure eliminates the need to temporarily store the received data in a file.

* 1
In the terminal device of the present embodiment, the function of the operation mode 2 has a simple configuration as described above, and thus the flash file system may not be used. In this case, in step S41 of FIG. 4, the difference data is stored in the reserved area of the flash ROM (or the work area on the RAM). In operation mode 1, since the OS that performs address conversion / memory protection using the MMU is operating, the reserved area in which the difference data is stored in step S41 is designated by a logical address. However, in the operation mode 2, the address must be specified by a physical address. Therefore, in order to be able to restore the difference data in step S51 of FIG. 5, information regarding the physical page arrangement is recorded as difference data arrangement information together with the logical address of the reserved area in which the difference data is stored in step S41. Is required.

  For example, such information can be expressed by storing a maximum of 4 Mbytes / 4 Kbytes = 1024 physical page numbers in the reserved area on the data flash in the order of storing the difference data. If the physical page number is expressed by the physical address (32 bits) at the top address of each page, a reserved area of 4 Kbytes is required on the data flash, but the stored physical pages are continuous. If there are places, it is possible to reduce the size of the effective differential data arrangement information by performing appropriate encoding based on the run length method. Specifically, an area composed of continuous physical pages is represented by a set of two values: “the physical address of the first address of the first page (of consecutive physical pages)” and “the number of consecutive”. Furthermore, if the former is 20 bits and the latter is 12 bits, and the encoding is performed to a 32-bit length, the size of the reserved area necessary for storing the differential data arrangement information does not exceed the size before encoding.

  The encoding format represents the position (starting physical address) and size (number of consecutive pages) of each area of differential data stored in one or more areas on the physical address space. The order of the areas is expressed by storing them in order.

  Note that in order to acquire a physical address corresponding to a predetermined logical page number, it is necessary to access the state inside the target OS. The OS may provide an API for acquiring such information, or may be acquired via a page table by modifying the OS or creating a device driver.

  As mentioned above, although the specific embodiment was shown and demonstrated about the method, program, and apparatus for updating the program of this invention, this invention is not limited to these. A person skilled in the art can make various changes and improvements to the configurations and functions of the invention according to the above-described embodiments or other embodiments without departing from the gist of the present invention.

  The method and program for updating the program of the present invention can be realized in a portable terminal device provided with data receiving means, storage means, data rewriting means, etc. Since it is specifically realized by using the above data receiving means, storage means, data rewriting means, etc., it is an invention that can be utilized industrially.

In the method, program, and apparatus for updating the program of this invention, it is a block diagram which shows roughly the hardware constitutions of the terminal device containing the program which is the object of an update. It is a functional block diagram which shows the functional structure based on the content of the process which the terminal device shown in FIG. 1 performs. It is a schematic diagram which illustrates the correspondence of the logical address space and physical address space at the time of performing address translation by the address translation means of the terminal device shown in FIG. It is a flowchart which shows the flow of the first half part of the program update process which the program execution means by the operation mode 1 performs. It is a flowchart which shows the flow of the second half part of the program update process which the program execution means by the operation mode 2 performs. It is a flowchart which shows the detail of the process in the difference data restoration step (S51) of FIG. 5 is a flowchart showing a flow of processing for a work area performed in a differential data reception step (S41 in FIG. 4) when a work area for storing difference data cannot be secured on a RAM.

Explanation of symbols

11 Program execution processing unit 111 CPU core 12 Storage unit 121 RAM
122 Flash ROM for program
123 Flash ROM for data
13 wireless communication unit 14 antenna 21 program execution means 211 program execution means 212 in the first operation mode program execution means 213 in the second operation mode 213 operation mode switching / restart execution means 214 address conversion means 22 storage means 221 first Program 222 Second program 223 Difference data 224 Difference data arrangement information 23 Difference data receiving means

Claims (20)

A method of updating a program of a terminal device using difference data for program update,
A difference data acquisition step for acquiring the difference data;
In a first operation mode in which memory management is performed by the OS, a difference data storage step for storing the difference data in a memory;
A step of storing difference data arrangement information for acquiring information on arrangement of the difference data in a memory and storing the information in the memory;
An operation mode switching step for performing switching for switching from the first operation mode to the second operation mode in which memory management by the OS is not performed while retaining the contents stored in the memory;
In the second operation mode, based on the difference data arrangement information stored in the memory, the difference data restoring step for acquiring the difference data from the memory;
A program update step for updating the program using the difference data;
Including methods. The memory is configured as a file system that can be used in the first operation mode and the second operation mode,
In the difference data storage step, the difference data is stored in a file on the file system;
In the difference data arrangement information storage step, as the arrangement information of the difference data, obtain and store information specifying a file storing the difference data;
2. The program update method according to claim 1, wherein, in the differential data restoration step, the differential data is acquired by reading a file storing the differential data based on the differential data arrangement information. The memory stores a dummy file having a size greater than or equal to the maximum size that the difference data can take,
The program update method according to claim 2, wherein in the difference data acquisition step, a process of overwriting the acquired difference data on the dummy file is performed. In the differential data storage step, the differential data is stored in an area on one or more physical address spaces in the memory;
2. The program update method according to claim 1, wherein, in the difference data arrangement information storage step, the position and size of the area in the physical address space and information regarding the storage order of the difference data are acquired and stored. .   5. The method according to claim 4, further comprising the step of reducing the number of areas in the physical address space required for storing the differential data in the memory before executing the differential data storing step. The program update method described in 1.   6. The method according to claim 4, further comprising a step of canceling a work unnecessary for the program update process and releasing a memory area used for the work before executing the differential data storage step. Program update method.   6. The program update method according to claim 4, further comprising a step of restarting the OS before executing the differential data storage step.   8. The program update method according to claim 1, wherein, in the differential data acquisition step, differential data for program update is acquired from the outside of the terminal device by communication means. 9.   9. The program update method according to claim 1, wherein the memory management by the OS is realized by address conversion between a logical address and a physical address by the MMU.   The program which performs the program update process of a terminal device using the method of any one of Claim 1 to 9. A terminal device including a program,
A memory for storing a program and data for updating the program;
Memory management means for managing the memory by an OS;
Differential data acquisition means for acquiring differential data for program update;
Program update means for updating the program using the difference data;
Operation mode switching for switching the operation mode between a first operation mode in which memory management by the OS is performed and a second operation mode in which memory management by the OS is not performed while retaining the contents stored in the memory Means and
In the first operation mode, the difference data acquired by the difference data acquisition unit is stored in the memory, and information regarding the arrangement of the difference data in the memory is acquired and stored in the memory.
In the second operation mode, a terminal device that acquires the difference data from the memory based on information relating to the arrangement of the difference data stored in the memory, and updates the program using the difference data. The memory is configured as a file system that can be used in the first operation mode and the second operation mode,
The difference data is stored in a file on the file system,
The difference data arrangement information is information for specifying a file storing the difference data,
The terminal device according to claim 11, wherein the difference data is acquired by reading a file storing the difference data based on the difference data arrangement information. The memory stores a dummy file having a size greater than or equal to the maximum size that the difference data can take,
The terminal device according to claim 12, wherein the difference data acquisition unit performs a process of overwriting the acquired difference data on the dummy file. The difference data is stored in an area on one or more physical address spaces in the memory,
12. The location and size of the area in a physical address space and information regarding the storage order of the difference data are acquired and stored when the difference data arrangement information is stored in a memory. Terminal equipment.   15. The method according to claim 14, further comprising area reduction means for reducing the number of areas on a physical address space necessary for storing the difference data in the memory before storing the difference data. The terminal device described.   The terminal device according to claim 15, wherein the area reduction unit stops a work unnecessary for the program update process and releases a memory area used for the work.   The terminal device according to claim 15, wherein the area reduction unit restarts the OS.   The terminal device according to any one of claims 11 to 17, wherein the difference data acquisition unit acquires the difference data for program update from the outside of the terminal device by a communication unit.   The terminal device according to claim 11, wherein the memory management unit realizes memory management by address conversion between a logical address and a physical address by an MMU.   A portable terminal comprising the terminal device according to any one of claims 11 to 19.

Images