JP2010218103A - Electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To selectively start a plurality of programs on an electronic apparatus by use of a relatively simple arrangement. <P>SOLUTION: The electronic apparatus 3 includes: a flash ROM 12 having a first memory bank which stores a first real-time operating system and a first application software and a second memory bank which stores a second real-time operating system and a second application software of a different version; a CPU 5 which starts either the first or second real-time operating system and the application software in the same bank from a predetermined operation start address; and a bank switching unit 9 which performs address translation by switching banks so that either the start address of the first real-time operating system in the first memory bank or the start address of the second real-time operating system in the second memory bank matches the operation start address. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronic device controlled by, for example, an embedded system.

  By using a plurality of memory banks loaded with different OSs (operating systems) and a memory bank connection circuit for connecting each memory bank to an arbitrary address accessible by the CPU, a plurality of OSs are executed on the same computer. An OS switching method that executes data and exchanges data among a plurality of OSs is known (see, for example, Patent Document 1).

  As another method for operating a plurality of OSs on a single device, the loader loads the guest OS when the power is turned on and the host OS is arranged at a predetermined position according to the address information. There has also been proposed a method in which various functions of both OSs can be used by generating a guest OS as a task (see, for example, Patent Document 2).

JP-A-4-175924 Japanese Patent Laid-Open No. 2003-241984

  Here, for example, when managing a plurality of application software of the same system having different versions in a device to which a real-time OS such as μITRON is applied, a combination of the application software and the OS is assigned to different physical addresses on the program storage memory. The form etc. which arrange | position are illustrated.

  More specifically, an OS (OS boot loader) stored with one version of the application software is arranged at address 0 of the physical address on the program storage memory, and the OS stored with the other version of the application software is programmed. It is arranged at a physical address other than address 0 on the storage memory.

  That is, since the CPU used in combination with the above-described μITRON or the like generally has a calculation start address starting at address 0, one version of the application software can be started as it is together with the OS when the apparatus is turned on.

  However, in the other version of the application software, the boot loader of the OS stored together is not arranged on the calculation start address of the CPU, so that its startup requires a complicated startup sequence.

  In general, a real-time OS that does not use a virtual memory (virtual address) is required to be compiled and linked in consideration of an optimal memory arrangement so as not to waste as much as possible when loading a program. In other words, considerations for optimizing the memory arrangement in consideration of such compilation and linking are required every time a new version of application software is upgraded.

  SUMMARY An advantage of some aspects of the invention is that it provides an electronic device that can selectively start a plurality of programs with a relatively simple configuration.

  To achieve the above object, an electronic apparatus according to the present invention includes a storage unit having a first storage area for storing a first program and a second storage area for storing a second program, and a predetermined calculation start address. And a calculation unit that activates one of the first and second programs, and an activation address of the first program in the first storage area or an activation address of the second program in the second storage area And an address conversion unit that performs address conversion so as to match the calculation start address.

  That is, in the present invention, since the address conversion is performed so that the start address of the first or second program matches the calculation start address of the calculation unit, it is restricted by the fixed calculation start address of the calculation unit. It is possible to individually switch and start a plurality of programs.

  ADVANTAGE OF THE INVENTION According to this invention, the electronic device which can selectively start a some program with a comparatively simple structure can be provided.

1 is a functional block diagram illustrating a configuration of an electronic device according to an embodiment of the present invention. The functional block diagram which shows the structure of the bank switching part with which the electronic device of FIG. 1 is provided. 2 is a memory map (before the electronic device main body is activated) of a flash ROM included in the electronic device of FIG. 1. FIG. 4A is a memory map showing the correspondence between the location of each program and the address when switching to the first memory bank. FIG. 4B is a memory map showing the correspondence between the arrangement of each program and the address when switching to the second memory bank. 2 is a flowchart showing start-up processing immediately after power-on for the electronic device of FIG. 1. 3 is a flowchart showing start-up processing in a normal mode after power-on for the electronic device of FIG. 1. 3 is a flowchart showing a startup process in a first bank fixed startup mode after powering on the electronic device of FIG. 1.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
As shown in FIG. 1, the operation of the electronic device 3 according to the present embodiment is controlled by a so-called embedded system. The CPU 5 functions as an arithmetic unit, a main memory (RAM) 6, an address bus 14, data A bus 15, a mode setting switch 7, a USB interface 8, a bank switching unit 9 that functions as an address conversion unit, an adjustment serial port 10, and a flash ROM (storage unit) 12 are provided.

  As shown in FIGS. 1 and 3, the flash ROM 12 functioning as a program (software) storage memory is composed of a rewritable EEPROM or the like that does not require power backup, and includes a first storage area, a second storage area, and a second storage area. It has 3 storage areas. A first real-time OS (real-time operating system such as μITRON) that is a first program and first application software that is started when the first real-time OS is started are installed in the first storage area. ing.

  In the second storage area of the flash ROM 12, as shown in FIG. 3, the second real-time OS such as μITRON as the second program and the above-mentioned first application software have the same system (same software name). And second application software that is activated in accordance with the activation of the second real-time OS. Here, the first and second application softwares are set to be read when the first and second real-time OSs are started, so that the first and second application softwares are started when the OSs start.

  In addition, in the first storage area and the second storage area of the flash ROM 12, as shown in FIG. 3, version information representing the versions of the first and second application software is stored. In the present embodiment, since the first application software is an old version and the second application software is the latest version, information representing version 1 is stored in the first storage area as shown in FIG. On the other hand, information indicating version 2 is stored in the second storage area.

  Further, as shown in FIG. 3, loader software (bank switching loader program) as a third program is stored in the third storage area of the flash ROM 12. The loader software acquires start program specifying information (to be described later) for specifying a program to be started from the first and second real-time OSs (first and second application software). The loader software acquires the activation program specifying information by detecting information representing the versions of the first and second application software stored in the first storage area and the second storage area, respectively. Furthermore, the loader software controls the operation of the bank switching unit 9 based on the acquired activation program specifying information.

  The mode setting switch 7 is constituted by a dip switch, for example, and is a switch for setting an operation mode to be described later when the electronic apparatus 3 is activated. The mode setting switch 7 can selectively set four types of operation modes. Further, the loader software reads the setting value of the mode setting switch 7 when the electronic device 3 main body is activated.

  As shown in FIG. 1, the USB interface 8 reads data of a new version of application software from a storage medium such as a USB memory and writes it to the flash ROM 12 when the application software stored in the flash ROM 12 is upgraded. Port.

  As shown in FIG. 1, the adjustment serial port 10 is, for example, IEEE1394 or other serial interface used for adjustment such as program debugging. For example, when application software is not stored in the flash ROM 12, the loader software has a function of writing application software into the flash ROM 12 via the adjustment serial port 10.

  The above-described adjustment serial port 10, USB interface 8, mode setting switch 7, flash ROM 12, bank switching unit 9, and main memory 6 are connected to the CPU 5 via the address bus 14 and the data bus 15, as shown in FIG. It is connected.

  Next, the configuration of the CPU 5 and bank switching unit 9 included in the electronic device 3 of the present embodiment, and the real-time OS and loader software stored in the flash ROM 12 will be described in detail. The CPU 5 of the present embodiment has a calculation start address of address 0, and can selectively start the first and second real-time OS stored in the flash ROM 12 by address 0 start.

  That is, as shown in FIG. 3, the bank switching unit 9 starts to calculate the start address of the first real-time OS in the first storage area of the flash ROM 12 or the start address of the second program in the second storage area. Address conversion is performed so as to match the address. More specifically, the first storage area and the second storage area are configured (managed) as a first memory bank and a second memory bank, respectively. Further, the bank switching unit 9 performs address conversion by bank switching for the first and second memory banks.

  More specifically, as shown in FIG. 3, the first real-time OS has a first storage area (first memory bank) so that its OS boot loader is stored at address 1000H of the physical address of the flash ROM 12. Is stored in advance. On the other hand, the second real-time OS is stored in advance in the second storage area (second memory bank) so that the OS boot loader is stored at address 2000H of the physical address of the flash ROM 12. Further, the bank switching loader software stores the calculation start address (address 0) of the CPU 5 in the third storage area of the flash ROM 12 so that the physical address to which the start address of the loader program is assigned is matched in advance. Has been. That is, the loader software is stored such that its activation address is address 0 of the physical address of the flash ROM 12, as shown in FIG.

  On the other hand, as shown in FIG. 2, the bank switching unit 9 configured as hardware includes an address non-replacement unit 9a, an address first replacement unit 9b, an address second replacement unit 9c, a bank switching register 9d, and a multiplexer (MUX). 9e is provided. This bank switching unit 9 makes it possible to replace the address (CPU / ADR) specified in response to an access request from the CPU 5 and the address (F / ADR) actually accessed in the flash ROM 12. is there.

  Specifically, as shown in FIG. 2, the address first replacement unit 9b replaces the designated address from the CPU 5, for example, “0000-0FFFH” with the address “1000-1FFFH”, and outputs it to the multiplexer 9e side. The address second replacement unit 9c replaces the designated address from the CPU 5, for example, “0000-0FFFH” with the address “2000-2FFFH”, and outputs the same to the multiplexer 9e side.

  Further, the address non-replacement unit 9a outputs the designated address from the CPU 5 to the multiplexer 9e side without replacing it. The bank switching register 9d whose operation is controlled by the loader software instructs the multiplexer 9e to switch the bank. The multiplexer 9e selects and selects one of the addresses output from the address non-replacement unit 9a, the first address replacement unit 9b, and the second address replacement unit 9c based on the switching instruction from the bank switching register 9d. The flash ROM 12 side is accessed by the address.

  Furthermore, the loader software for controlling the bank switching unit 9 (bank switching register 9d) has the following functions. That is, the loader software loaded and executed on the main memory 6 by the CPU 5 from address 0 immediately after turning on the power of the electronic device 3 main body reads the setting value of the mode setting switch 7 and starts the operation of the electronic device 3 main body. Recognize the mode. There are four types of operation modes: normal mode (latest version activation mode), old version activation mode, first bank fixed activation mode, and second bank fixed activation mode.

  In the normal mode, the loader software acquires the above-described startup program specifying information by detecting the version information of the first and second application software stored in the first and second memory banks, respectively. Based on the information, the bank switching unit 9 is controlled so as to switch to the memory bank storing the new version of the application software.

  In this embodiment, since the new version of application software (version 2 application) is stored in the second memory bank, the loader software is replaced by the address second replacement unit 9c as shown in FIG. The bank switching unit 9 is controlled so that the selected address is selected. At this time, as shown in FIGS. 3 and 4B, the address of the OS boot loader of the second real-time OS is changed from the address 2000H before the bank switching to the address 0, and the calculation start address of the CPU 5 is changed. Match. Thereby, the second real-time OS and the second application software are activated under the control of the CPU 5.

  In the old version activation mode, the loader software acquires the activation program specifying information by detecting the version information of the first and second application software stored in the first and second memory banks, respectively. Based on the information, the bank switching unit 9 is controlled so as to switch to the memory bank storing the old version of the application software.

  In the present embodiment, since the first version of the first application software (version 1 application) is stored in the first memory bank, as shown in FIG. 2, the loader software includes the address first replacement unit 9b. The bank switching unit 9 is controlled so that the address replaced with is selected. At this time, as shown in FIGS. 3 and 4A, the address of the OS boot loader of the first real-time OS is changed from the address 1000H before the bank switching to the address 0 and the calculation start address of the CPU 5 is changed. Match. Thereby, the first real-time OS and the first application software are activated under the control of the CPU 5.

  In the first bank fixed start mode, the loader software acquires the set value itself of the mode setting switch 7 as start program specifying information, and switches the bank so as to forcibly switch to the first memory bank based on the acquired information. The unit 9 is controlled. That is, in the case of the first bank fixed activation mode, the loader software controls the operation of the bank switching unit 9 as in the above-described old version activation mode.

  In the second bank fixed start mode, the loader software acquires the set value itself of the mode setting switch 7 as start program specifying information, and switches the bank so as to forcibly switch to the second memory bank based on the acquired information. The unit 9 is controlled. That is, in the case of the second bank fixed activation mode, the loader software controls the operation of the bank switching unit 9 as in the normal mode described above.

  Next, application software version upgrade will be described. The application software to be upgraded includes an installer that operates under the control of a real-time OS, and is provided in a form stored in, for example, a USB memory. As shown in FIG. 1, the version of the application software is upgraded by reading the data of the new version of the application software in the USB memory via the USB interface 8 and reading the read data into the first and second memories in the flash ROM 12. This is realized by installing in any storage area of the bank.

  The installation of the application software may be an upgrade installation overwriting the old version, or after deleting the old version, a new version of the application software may be newly installed. Here, in the electronic device 3 of the present embodiment, since the combination of the real-time OS and application software can be switched individually and activated, for example, the upgrade of the application software fails and the OS is activated from one memory bank. Even if it becomes impossible, the system can be recovered by starting the OS from the other memory bank.

  In the electronic device 3 of the present embodiment, as shown in FIGS. 3, 4A, and 4B, the application software is actually installed in any of the first and second memory banks. The leading address of the memory bank that is rising (address where the OS boot loader is located) is address 0, while the leading address of the other memory bank where the application software is not rising is the same address other than address 0 (this embodiment) In the example of FIG. 4 (a) and FIG. 4 (b), the address is always 1000H. As a result, the application software in the flash ROM 12 is always updated from the same reference address without considering whether the memory bank in which the application software is currently operating is the first or second memory bank. You only need to update to the version.

Next, the startup operation of the electronic apparatus 3 configured as described above will be described based on the flowcharts shown in FIGS. 5 to 7 in addition to FIGS. 1 to 4 described above.
As shown in FIGS. 3 and 5, when the electronic device 3 is initialized by powering on the electronic device 3, the loader software stored at the physical address 0 of the flash ROM 12, which is the calculation start address of the CPU 5, is loaded. Then, it is loaded on the main memory 6 and activated (S1).

  As shown in FIG. 5, the activated loader software reads the set value of the mode setting switch 7 (S2), and the normal mode, the old version activation mode, and the first bank are fixed as the operation mode when the electronic device 3 is activated. It is detected which operation mode of the start mode or the second bank fixed start mode is requested (S3 to S6).

  For example, when the setting value of the mode setting switch 7 is a request for activation in the normal mode, the loader software is a predetermined (valid) application software as shown in FIG. It is detected whether it is installed in one of the memory banks (S11). If the predetermined application software is not stored in either the first or second memory bank (NO in S11), the loader software is stored in a predetermined storage device connected via the adjustment serial port 10. A process (downloading) of writing application software to any one of the memory banks in the flash ROM 12 is started (S12), and the writing completion is waited (S13).

  Next, as shown in FIGS. 3 and 6, the loader software detects the version information of the first and second application software stored in the first and second memory banks in the flash ROM 12, for example. For example, it is detected whether the second application software stored in the second memory bank is a newer version (latest version) than the first application software stored in the first memory bank (S14). .

  If the version of the second application software stored in the second memory bank is newer (or if, for example, application software is stored in the second memory bank via the adjustment serial port 10) (S14 As shown in FIG. 2, the loader software controls the bank switching unit 9 so that the bank switching to the second memory bank is performed (S15). In this case, as shown in FIGS. 3 and 4B, the address of the OS boot loader of the second real-time OS is changed from address 2000H before bank switching to address 0.

  On the other hand, if the version of the second application software stored in the second memory bank is older (NO in S14), the loader software switches the bank to the first memory bank as shown in FIG. The bank switching unit 9 is controlled as shown in FIG. In this case, as shown in FIGS. 3 and 4 (a), the address of the OS boot loader of the first real-time OS is changed from address 1000H before bank switching to address 0.

  Thereafter, the loader software transfers control (startup process) to the OS boot loader of the real-time OS in any bank that has been switched to address 0, and the loader software itself is transferred to address 2000H and ends the process (S17). In addition, since the calculation start address (address 0) of the CPU 5 matches the address at which the OS boot loader of the real-time OS matches, a new version is activated along with the activation of the real-time OS in the memory bank selected by bank switching. Application software is started (S18).

  Further, for example, when the set value of the mode setting switch 7 described above requests activation in the normal mode, the loader software performs the normal mode shown in FIG. 6 in S21 to S23 as shown in FIG. The same processing as S11 to S13 is performed. Further, the loader software controls the bank switching unit 9 to forcibly switch to the first memory bank (S24). As a result, as shown in FIGS. 3 and 4A, the address of the OS boot loader of the first real-time OS is changed from address 1000H before bank switching to address 0.

  Thereafter, the loader software transfers control to the OS boot loader of the first real-time OS that has been switched to address 0 (S25). Further, the OS boot loader switched from the calculation start address of the CPU 5 to the address 0 is read out, whereby the first application software is activated in accordance with the activation of the first real-time OS (S26).

  As described above, according to the electronic device 3 of the present embodiment, the address storing the OS boot loader of the first real-time OS in the first memory bank or the first real-time OS in the first memory bank. Since the address conversion is performed by switching the bank so that the address storing the OS boot loader matches the calculation start address of the CPU, a plurality of OSs and application softwares are not restricted by the fixed calculation start address of the CPU 5. Can be activated selectively.

  Here, since the real-time OS applied by the electronic device 3 of the present embodiment generally does not use virtual memory (virtual address) or the like, when loading a program, an optimal memory arrangement is provided so as not to waste as much as possible. Considering compilation and linking is required. Therefore, in the electronic device 3 of the present embodiment, attention is paid to program compilation and linking when the application software is upgraded by enabling address conversion in accordance with the calculation start address of the CPU 5 by bank switching as described above. This eliminates the need for consideration for optimizing the memory layout.

  Although the present invention has been specifically described with the embodiments, the present invention is not limited to these embodiments, and various modifications can be made without departing from the scope of the invention. That is, in the above embodiment, the application of the electronic device of the present invention has not been specifically exemplified. For example, for example, terrestrial digital television broadcasting, BS analog / digital broadcasting, CS that performs video distribution by wire or wireless, CS The configuration of the present invention can be applied to broadcasting equipment used for analog / digital broadcasting, Internet-compatible television broadcasting, and the like.

  In addition, portable information terminals such as mobile phones and PDAs, digital cameras, televisions, DVD recorders, home appliances such as microwave ovens, flash memory recorders, network devices, electronic measuring devices, industrial automatic machines, automobile control systems The configuration of the present invention can be applied to any electronic device using an embedded system such as a car navigation system, an elevator, a vending machine, or a medical device.

  DESCRIPTION OF SYMBOLS 3 ... Electronic device, 5 ... CPU (calculation part), 6 ... Main memory (RAM), 7 ... Mode setting switch, 8 ... USB interface, 9 ... Bank switching part (address conversion part), 9a ... Address non-replacement part, 9b: Address first replacement unit, 9c: Address second replacement unit, 9d: Bank switching register, 9e: Multiplexer (MUX), 10: Adjustment serial port, 12: Flash ROM (software storage memory)

Claims (7)

A storage unit having a first storage area for storing a first program and a second storage area for storing a second program;
A calculation unit that activates one of the first and second programs from a predetermined calculation start address;
An address conversion unit that performs address conversion so that the start address of the first program in the first storage area or the start address of the second program in the second storage area matches the calculation start address When,
An electronic apparatus comprising: The first storage area and the second storage area are configured as first and second memory banks, respectively.
Further, the address conversion unit performs address conversion by bank switching for the first and second memory banks.
The electronic device according to claim 1. As a third program for acquiring start program specifying information for specifying a program to be started out of the first and second programs, and for controlling the operation of the address conversion unit based on the acquired start program specifying information. Loader program,
The electronic apparatus according to claim 1, further comprising: The storage unit stores a third storage area in which the loader program is stored so that the calculation start address and the physical address to which the start address of the loader program is assigned are matched in advance.
The electronic device according to claim 3, further comprising: The first storage area stores a first operating system, which is the first program, and first application software that is started when the first operating system is started.
In the second storage area, the second operating system, which is the second program, and application software of the same system whose versions are different from those of the first application software, and for starting the second operating system. Second application software to be started is stored,
The electronic device according to claim 1, wherein the electronic device is an electronic device.   6. The electronic apparatus according to claim 5, wherein the first and second operating systems are real-time operating systems. The loader program obtains the activation program specifying information by detecting information representing versions of the first and second application software stored in the first storage area and the second storage area, respectively.
The electronic apparatus according to claim 5 or 6, wherein

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