JP5418097B2 - Information processing apparatus, image forming apparatus, and operation mode switching method - Google Patents

Description

  The present invention relates to an information processing apparatus having a power saving mode, and more particularly to an information processing apparatus, an image forming apparatus, and an operation mode switching method that communicate via a network even in the power saving mode.

  In addition to information processing apparatuses such as personal computers, information processing apparatuses included in digital multi-function peripherals and printers have a power saving mechanism. For example, in the information processing apparatus, as an operation mode, in addition to the normal mode in which normal drive power is supplied to each internal device, the supply of drive power to some devices is stopped or the supply amount thereof Some have a power saving mode in which the power consumption is reduced as compared with the normal mode.

  When such information processing apparatus does not receive request packet data for requesting printout or the like via a network in a normal mode for a certain period, the information processing apparatus shifts to a power saving mode to reduce power consumption of the entire apparatus. When receiving the request packet data from the network, the information processing apparatus in the power saving mode resumes the power supply to the device and returns to the normal mode (see, for example, Patent Document 1).

  Patent Document 1 discloses an image in which when a communication control unit of an image forming apparatus in a power saving mode receives packet data, the CPU is activated and the activation target component apparatus corresponding to the port number specified by the packet data is switched to the normal mode. A forming apparatus is disclosed. Since the communication control unit, not the CPU, determines the activation target component, the power consumption can be reduced as compared with the CPU.

  However, since the image forming apparatus described in Patent Document 1 determines the activation target component device only by the port number, there is a problem that the image forming apparatus cannot be applied unless the relationship between the port number and the activation target component is fixed. For example, when the unexpected packet data specifies a port number that is already associated with the activation target component, the activation target component is switched to the normal mode even if it is not necessary to switch to the normal mode.

  Setting information managed by a controller (including a CPU) may be used in order to more appropriately determine whether or not to activate a target component or activation. For example, an internal setting accessed by a controller (including a CPU) to receive packet data requesting image forming processing in the power saving mode and determine whether or not a device such as an image forming unit needs to be activated. Information may be required. However, when the setting information is used, when the image forming apparatus receives the packet data, the entire controller is first switched to the normal mode, and there is a problem that unnecessary power is consumed.

  In view of the above problems, the present invention provides an information processing apparatus, an image forming apparatus, and an operation mode switching method capable of reducing power consumption when performing packet analysis processing that requires setting information and the like. With the goal.

The present invention relates to a communication unit that communicates via a network, a data processing unit that processes data using a plurality of divided memory blocks as a working memory, and activation of an application that is supplied with power when the data processing unit is operated. A non-volatile memory for storing conditions, a second memory block that virtualizes hardware for a plurality of OSs, assigns a first memory block to the first OS, and does not overlap with the first memory block for the second OS and virtualization means for assigning a power saving mode where only the first OS is started, the non-power saving mode and a mode switching means for switching said first OS and the second OS is started up, the power-saving mode when, from the power supply, the communication means, only to the data processing means and said first memory block, and the power management means for supplying power, In order to store the data received by the first communication control means during the power saving mode, and the first communication control means for controlling the communication means to receive data during the startup of the first OS a data buffer provided in said first memory block, the communication means between the power saving mode by referring to the activation condition based on the data received, the application running on the second OS start whether it is necessary, said initiation determining means on the first OS, when the activation determination means determines that it is necessary to start the application, the mode switching means, from the power saving mode switching to the non-power saving mode, to activate the said application and said second OS, the second communication control unit of the second OS which is started by the application, the Reading data via the virtualized data reading means reads data from Tabaffa, notifying the application, to provide an information processing apparatus characterized by.

  It is possible to provide an information processing apparatus, an image forming apparatus, and an operation mode switching method that can reduce power consumption when performing packet analysis processing that requires setting information and the like.

1 is an example of a schematic configuration diagram of an image forming apparatus. It is an example of the hardware block diagram of a controller. It is an example of the figure which shows a network packet (TCP header structure). It is a figure which shows an example of a software structure. It is a figure which shows an example of the division of the memory block by partitioning. It is a figure which shows an example of the memory map of OS1, and an example of the memory map of OS2. FIG. 10 is an example of a flowchart illustrating a procedure when the image forming apparatus enters a power saving mode. FIG. 3 is an example of a flowchart illustrating a procedure when the image forming apparatus returns to a normal mode. FIG. 10 is an example of a flowchart illustrating a processing procedure of application 1. It is an example of the figure explaining the storage structure of a data buffer in detail. It is an example of the figure explaining the relationship of the pointers 1-3. It is an example of the figure explaining the relationship of the pointers 1-3. It is an example of the figure explaining the relationship of the pointers 1-3.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
First, an outline of features of the image forming apparatus 100 of the present embodiment will be described.

  The image forming apparatus 100 according to the present embodiment partitions a memory access range for each OS using a virtualization technique. By using partitioning, which is one of the features of the virtualization technology, the range of memory that can be accessed by the OS can be limited. The power supply can be reduced to zero.

  Therefore, the controller (CPU) determines from the setting information on the controller and the received packet data whether it is necessary to receive the packet data from the external network in the power saving mode and switch to the normal mode to start the application. In this case, the power consumption of the image forming apparatus 100 can be reduced.

  In addition, since the application cannot access a memory range to which power is not supplied, the application can safely acquire necessary setting information on the controller and analyze the packet.

[Hardware configuration diagram]
FIG. 1 shows an example of a schematic configuration diagram of the image forming apparatus 100. The image forming apparatus 100 includes a system management unit 11, an engine unit unit 12, and a power supply unit unit 13. The system management unit 11 determines whether or not the engine unit unit 12 needs to be activated, and if necessary, controls the power supply unit unit 13 to supply power from the power supply unit unit 13 to the engine unit unit 12 (normal mode). ). If the system management unit 11 determines that the engine unit unit 12 is not activated, the system management unit 11 controls the power supply unit unit 13 to cut the power supplied from the power supply unit unit 13 to the engine unit unit 12. Yes (power saving mode). The system management unit realizes power saving by appropriately switching between the power saving mode and the normal mode. The system management unit 11 is connected to the engine unit unit 12 and the power supply unit unit 13 via, for example, a PCI-Express bus.

  The system management unit 11 includes an operation unit 14 and a controller 15, the engine unit unit 12 includes a scanner unit 16 and a printer unit 17, and the power supply unit unit 13 includes a heater driving unit 19 and a DC power supply 20. The power supply unit 13 is connected to an outlet (commercial power supply). A fixing unit 18 is mounted on the printer unit 17, and a heater driving unit 19 controls the temperature of the fixing unit 18.

  The operation unit 14 provides a user interface with the image forming apparatus 100, and includes an LCD (Liquid Crystal Display), a touch panel, and a key switch. The operation unit 14 displays various states and operation methods of the image forming apparatus 100 on the LCD, and accepts key presses and key switch inputs on the touch panel. The controller 15 will be described below. The controller 15 controls the entire image forming apparatus 100.

  The scanner unit 16 exposes the document placed on the contact glass with an exposure lamp, and optically scans the image surface of the document. The read data is imaged on the light receiving surface of the CCD by the lens, and the CCD performs photoelectric conversion to read digital image data. The CCD is, for example, a full color CCD (or a full color line CCD), and performs photoelectric conversion into each color of red (R), green (G), and blue (B).

  The printer unit 17 performs processing such as exposure and development on the intermediate transfer belt and the photosensitive drum to form a toner image, and the transfer unit transfers the toner image to a sheet. Thereafter, the sheet is conveyed to the fixing unit 18 where the toner image is fixed on the sheet by heat and pressure.

  The power supply unit generates a DC power supply 20 from a commercial power supply, and further boosts it to supply it to the fixing unit 18. The heater drive unit 19 controls the temperature of the fixing unit 18 by turning on / off the supply of the DC power source 20 or controlling the supply amount.

  FIG. 2A shows an example of a hardware configuration diagram of the controller 15. The controller 15 includes a CPU 22, a memory 21, a hard disk I / F 23, a hard disk 24, a network I / F 25, and an engine I / F 26 that are connected via a system bus 27.

  The CPU 22 has a nonvolatile memory, and setting information is stored in the nonvolatile memory 28. There are various kinds of setting information to be stored. In the present embodiment, for example, information included in the data in the “data” field of the TCP packet described below, and whether or not the engine unit unit 12 is activated, or It is the table etc. which matched the engine to start among engine unit parts 12.

  In this embodiment, the CPU 22 has a non-volatile memory for storing setting information. However, if the non-volatile memory is a non-volatile memory and can be controlled to supply power, the setting information is not limited. Can be stored. In this case, the nonvolatile memory connected to the system bus 27 is supplied with power when the CPU 22 operates.

  The memory 21 is divided into memory blocks 1 to 4. Each of the memory blocks 1 to 4 is a volatile memory. Although four memory blocks are shown in the figure, two or more memory blocks are sufficient, and five or more memory blocks may be used.

  The hard disk 24 mainly stores digital image data, additional information of the digital image data, font data, a program (application 31), an OS 32, and the like. The hard disk I / F 23 is, for example, IDE (Integrated Drive Electronics) or an ATA connection interface that is standardized by expanding IDE. The network I / F 25 is an Ethernet card, for example, and enables connection to an external network (LAN, WAN, Internet, etc.). An operation unit 14, an engine unit unit 12, and a power supply unit unit 13 are connected to the engine I / F 26.

  The CPU 22 executes the program stored in the hard disk 24 using the memory blocks 1 to 4 as a working memory. With the above virtualization, the memory blocks 1 to 4 that can be seen from each application can be limited to four or less. Such a restriction is set from software for realizing virtualization (for example, setting of a hypervisor described later).

  Each of the memory blocks 1 to 4 can control whether or not the CPU 22 individually supplies power by a switch or the like for individually turning on / off the power line connected from the power supply unit 13. Whether the CPU 22, the hard disk I / F (including the hard disk 24) 23, the network I / F 25, and the engine I / F (including the engine unit unit 12 and the operation unit 14) 26 supply power individually. The CPU 22 can control whether or not.

  The controller 15 of the present embodiment has at least two operation modes of a normal mode and a power saving mode. In the normal mode, all memory blocks 1 to 4, CPU 22, hard disk I / F (including hard disk 24) 23, network I / F 25, and engine I / F (including engine unit unit 12 and operation unit 14) 26 This is an operation mode in which power is supplied to. The power saving mode includes the CPU (for example, the drive frequency may be controlled to be lower than the normal mode) 22, a part of the memory blocks 1 to 4 (for example, the memory block 1), and the network device I / F. This is a mode in which power is supplied only to the above. That is, power is not supplied to the hard disk I / F 23 and the engine I / F 26. As will be described later, the application 1 that is activated in the normal mode can be executed by the CPU 22 without using the hard disk 24. Alternatively, it is assumed that the hard disk 24 is stopped after the application 1 is started.

  In FIG. 2B, blocks to which power is supplied in the power saving mode are indicated by hatching. As illustrated, in the power saving mode, power is supplied only to the CPU 22, the memory block 1, and the network I / F 25.

  In FIG. 2, one CPU 22 is provided, but a multi-CPU having a plurality of CPUs 22 or a multi-core CPU having a plurality of CPU cores may be mounted on the controller 15. In this case, the OS1 and OS2 of FIG. 4 can be executed for each CPU or each CPU core, and since power supply to the CPU or CPU core can be reduced in the power saving mode, more power saving is possible.

[Network packet]
The network packet will be described with reference to FIG. FIG. 3 shows a TCP header structure. A horizontal row represents 32 bits, the left end indicates the start of a bit (zero bit) and the right end indicates the end of a bit (31 bits). The TCP header is divided into several fields.

  The “transmission source port” field stores a value of 1 to 65535, which is a number for identifying the transmission source application. The “destination port” field stores a value from 1 to 65535, which is a number for identifying the destination application. The “sequence number” field stores a number for ordering data to be transmitted. The “acknowledgment response number” field stores information indicating, by byte position, how far the received data has been received. The “data offset” field stores information indicating the position where the TCP data starts. Various flags are stored in the “code bit” field. In the “window size” field, the window size of the receiving side is stored for transmission to the other party. The “TCP checksum” field stores inspection data for checking the consistency of the TCP packet. The “urgent pointer” field stores information that is valid when the URG flag of the code bit is 1. TCP data is stored in the “data” field.

  Therefore, if the network I / F 25 reads the first 32 bits in which the transmission source port and the destination port are stored in the TCP header, it is possible to switch processing by application (port). However, this method cannot cope with cases where applications using the same port need to perform different processing. Therefore, some application (application 1 described later) determines whether another application (application 2 described later) depends on whether the data in the “data” field received by the network I / F 25 includes information registered in the setting information. It is determined whether or not it is necessary to start (whether or not it is necessary to shift to the normal mode).

[Virtualization software configuration]
FIG. 4A is a diagram illustrating an example of a software configuration. Virtualization is a technique for virtualizing the hardware 34 for the OS 32 or the application 31. Two major virtualization technologies are known. Among these, host OS type virtualization is a technique for executing commercially available virtualization software on a general OS (Windows (registered trademark) or the like). The virtualization software generates one or more virtual machines (OS 32 and application 31) and executes them. Therefore, the virtualization software can be executed by the CPU 22 in the same manner as the application 31, and a virtual environment can be realized by an information processing apparatus that operates a general OS without preparing a dedicated platform. On the other hand, it is said that the host OS type virtualization has a large overhead.

  Another hypervisor type virtualization is a technique for starting virtualization software directly from the BIOS of the hardware 34 without starting a general OS. The activated virtualization software is called a hypervisor 33 (corresponding to the virtualization means in the claims). The hypervisor 33 generates one or more virtual machines (OS 32 and application 31) and executes them. Therefore, hypervisor type virtualization is said to increase the processing speed because a virtual machine can be executed without using a general OS.

  FIG. 4A shows a software configuration in a hypervisor type virtualization system. It can be similarly implemented in a host OS type system. The hypervisor 33 has two OS1 and OS2 installed, provides power saving mode processing on one OS (eg, OS1), and provides normal mode processing on the other OS (eg, OS2). To do. Therefore, the application 2 activated on the OS 2 is, for example, an application 31 that performs normal operations such as image formation, scanning, and facsimile transmission / reception. Actually, there are a plurality of applications 2, but only one application is shown in the figure. All devices (hard disk I / F 23, engine I / F 26) except the network I / F 25 are controlled by the application 2 on the OS 2.

  By such virtualization, the hypervisor 33 partitions the memory blocks 1 to 4. The broad partitioning is to virtualize the OSs 1 and 2 with respect to the applications 1 and 2. More narrowly, by virtualizing the OSs 1 and 2, the files and memories accessed by the applications 1 and 2 running on the OSs 1 and 2 are limited. For example, in the partitioning, the hypervisor 33 limits the range in which the OSs 1 and 2 can access the memory space and file system of the controller 15. The restricted OSs 1 and 2 do not recognize that there is a memory or file other than the accessible memory space and file system. Therefore, OS1 does not access the memory space and file system of OS2, and OS2 does not access the memory space and file system of OS1, and high security can be realized.

  In this embodiment, the memory space used by OS1 is partitioned into memory block 1, and the memory space used by OS2 is partitioned into memory blocks 2-4.

  FIG. 5 is a diagram illustrating an example of the division of the memory blocks 1 to 4 by partitioning. As shown in the drawing, the memory block 1 is used by the OS 1 and the remaining memory blocks 2 to 4 are used by the OS 2. Although the memory blocks 1 to 4 have the same capacity, they need not necessarily have the same capacity.

  FIG. 4B shows an example of a functional block diagram of the application 1. The function of FIG. 4B is realized by the CPU 22 executing a program. The activation determination unit 41 determines whether or not the application 2 needs to be activated. In the present embodiment, the necessity of starting the application 2 is synonymous with the necessity of shifting from the power saving mode to the normal mode. The power saving mode transition determination unit 42 determines whether or not it is necessary to transition from the normal mode to the power saving mode. The power control unit 43 controls the power supply unit unit 13 to supply power to a predetermined device in each of the normal mode and the power saving mode. As shown in FIG. 2B, the power control unit 43 is configured to supply power only to the memory block 1, the CPU 22, and the network I / F among the memory blocks 1 to 4 in the power saving mode. Request to unit unit 13. In the normal mode, the power control unit 43 requests the power supply unit unit 13 to supply power to the memory blocks 1 to 4, the CPU 22, the hard disk I / F, the network I / F, and the engine I / F. The mode switching unit 44 executes a series of processes for switching the controller 15 from the normal mode to the power saving mode or from the power saving mode to the normal mode.

  6A shows an example of the memory map of OS1, and FIG. 6B shows an example of the memory map of OS2. On the OS 1 memory, an OS 2 boot ROM area, an OS 1 boot ROM area, a free RAM 2 area, a network I / F control register, a nonvolatile memory 28, and a free RAM area 1 are arranged. In addition, a free RAM 2 area, a hard disk I / F control register, an engine I / F control register, a nonvolatile memory 28, and a free RAM 1 area are arranged on the OS2 memory. The free RAM 1 area and free RAM 2 area of the OS 1 correspond to the memory block 1 and are used by the OS 1. The free RAM 1 area and free RAM 2 area of the OS 2 correspond to the memory blocks 2 to 4 and are used by the OS 2. It is an area.

  A nonvolatile memory for storing setting information is shared by OS1 and OS2. On the other hand, since neither the hard disk I / F control register nor the engine I / F control register can be accessed from the OS 1, the application 1 can operate safely with respect to the engine unit 12 regardless of the power supply state. Become.

  Further, since the nonvolatile memory 28 in the CPU 22 is shared by OS1 and OS2, the OS1 can confirm the setting information read in the normal mode without starting the OS2.

  Note that the OS1 boot ROM is a ROM that stores a program for performing system settings, initialization of the hardware 34, and the like when the OS1 boot ROM and the OS2 boot ROM start OS2, respectively, and are fixed at predetermined addresses. . The OS1 boot ROM program causes the CPU 22 to execute the OS1 using the free RAM1 area and the free RAM2 area as work memory. In addition, the OS 1 automatically starts the application 1.

  When shifting to the normal mode, the mode switching unit 44 of the application 1 causes the CPU 22 to execute the OS2 boot ROM program via the hypervisor 33, and the OS2 uses the free RAM1 area and the free RAM2 area in FIG. To start. Further, the mode switching unit 44 causes the OS 2 to activate the application 2 via the hypervisor 33.

[Access to hardware by OS 1 and 2]
Returning to FIG. 4, the hypervisor 33 virtualizes the hardware 34 for each of the applications 1 and 2. Specifically, the hypervisor 33 receives a system call requesting the hardware 34 to provide a function to the hardware 34 performed in the kernels of the OSs 1 and 2, for example, and arbitrates use requests of the hardware 34 from the OS1 and the OS2. Then, the hypervisor 33 calls the hardware 34 and provides the functions of the hardware 34 to the OSs 1 and 2 (applications 1 and 2).

In this embodiment, access to the hardware 34 by the applications 1 and 2 has the following restrictions.
(A) The application 1 can directly access the network I / F 25 via the physical driver 35.
(B) The application 2 accesses the network I / F 25 via the virtual driver 37, the virtual driver I / F 38, the data buffer 36, and the physical driver 35.
(C) The application 2 outputs a use request to the hard disk I / F 23 and the engine I / F 26 via the virtual driver 37 and the virtual driver I / F 38.

  This embodiment is particularly characterized by the access method (b). That is, the network I / F 25 is shared between the OS 1 and OS 2 via the virtual driver I / F 38 and the data buffer 36.

  The OS 1 is activated in the power saving mode. As described above, since the network I / F 25 is activated even in the power saving mode, the application 1 can analyze a packet received via the network. The OS 1 has a physical driver (device driver) 35 that directly controls the network I / F 25, and receives packets via the network without going through the hypervisor 33 in the power saving mode. As long as processing is possible on the OS 1, the application 1 processes packets from the network without starting up the OS 2.

  In the power saving mode, the application 1 stores the packet received by the network I / F 25 in the data buffer 36. The protocol stack 1 and the protocol stack 2 are protocol processing units that perform data processing according to the protocol. For example, in the case of TCP / IP, an application layer (for example, HTTP), a transport layer (for example, TCP), a network layer (for example, IP), a link layer (for example, Ethernet (registered trademark)), a physical layer (for example, Ethernet) RJ45). The protocol stack 1 and the protocol stack 2 perform processing corresponding to the protocol for each layer, and exchange processing results in a form suitable for the interface between the layers. Note that the applications 1 and 2 may be responsible for processing of some layers.

  In the normal mode, the application 2 can read the packet in the data buffer 36 via the virtual driver 37 and the virtual driver I / F 38. The virtual driver I / F 38 reads a packet from the address of the data buffer 36 indicated by the pointer 3 described later, and outputs the packet to the virtual driver 37. The virtual driver 37 outputs the packet read by the virtual driver I / F 38 to the protocol stack 2. The protocol stack 2 performs protocol processing on the acquired packet and provides it to the application 2. As a result, the application 2 can execute image formation, fax transmission / reception, and the like by using the packet received when the controller 15 is in the power saving mode without requesting retransmission.

[Procedure for transition to power saving mode]
The procedure when the image forming apparatus 100 enters the power saving mode will be described with reference to FIG. Before entering the power saving mode, both the application 1 and the application 2 are activated. From this state, when the power saving mode transition determination unit 42 detects, for example, that a packet is not received for a predetermined time or longer, the engine unit unit 12 does not operate, an operation is not accepted from the operation unit 14, and the like. It is determined to shift to the power saving mode. Thereby, the mode switching unit 44 starts shifting to the power saving mode (S10).

  First, the mode switching unit 44 requests the hypervisor 33 to save the application 2 (S20). The saving includes storing the setting information in the nonvolatile memory 28, storing necessary information such as the setting state and log of the application 2 in the hard disk 24, and the like.

  Next, the mode switching unit 44 stops the virtual driver I / F 38 leaving only the device (network I / F 25) that requires the OS 1 (S30).

  In the power saving mode, a packet that reaches the network I / F 25 is supplied to the application 1 via the physical driver 35, the data buffer 36, and the protocol stack 1 (S40). The activation determination unit 41 analyzes the packet data and determines whether the application 2 needs to be activated.

  The mode switching unit 44 requests the hypervisor 33 to save the OS 2 (S50). When a packet that needs to use the OS 2 comes, the mode switching unit 44 requests the hypervisor 33 to activate the OS 2 and the application 2.

  Further, the power control unit 43 requests the power supply unit unit 13 to limit power supply corresponding to the power saving mode (S60). As described above, since the network I / F 25, the memory block 1, and the CPU 22 are activated in the power saving mode, the power control unit 43 includes the memory blocks 2 to 4, the engine I / F 26, and the hard disk I / F. The power supply unit 13 is requested to stop supplying power to F23. When the power supply is restricted, the image forming apparatus 100 enters the power saving mode (S70).

[Normal mode transition procedure]
A procedure when the image forming apparatus 100 returns to the normal mode will be described with reference to FIG.
The activation determination unit 41 of the application 1 analyzes the packet received by the network I / F 25 and determines whether or not the application 2 needs to be activated. For example, if the packet is a request for printing, the activation determination unit 41 starts returning to the normal mode (S110). The process of step S110 will be described with reference to the flowchart of FIG.

  The mode switching unit 44 requests the power supply unit unit 13 to resume power supply to the engine I / F 26, the hard disk I / F 23, and the memory blocks 2 to 4 (S120).

  Also, the mode switching unit 44 and the hypervisor 33 are requested to activate the OS 2 (S130). Further, the mode switching unit 44 keeps the packet received from the network I / F 25 stored in the data buffer 36 after the OS 2 is restored.

  When the OS 2 is activated, the mode switching unit 44 requests the hypervisor 33 to activate the application 2 (S140).

  When the application 2 is activated, the mode switching unit 44 requests to activate the virtual driver I / F 38 (S150).

  When the virtual driver I / F 38 is activated, the mode switching unit 44 requests the virtual driver 37 to read the packet in the data buffer 36 via the hypervisor 33. The virtual driver 37 accesses the data buffer 36 via the virtual driver I / F 38 and acquires a packet. Therefore, after the OS 2 is restored, the application 2 acquires a packet. The access to the data buffer 36 by the virtual driver I / F 38 will be described later.

  The mode switching unit 44 causes the application 1 to stop network processing (S160). Although the application 1 remains activated, the network processing is handled by the application 2, so that redundant power consumption can be prevented. This completes the transition to the normal mode (S170).

[Processing procedure by application 1]
FIG. 9 is an example of a flowchart showing the processing procedure of the application 1. The procedure of FIG. 9 is repeatedly executed when the power saving mode is entered.

  The activation determination unit 41 periodically monitors whether or not the network I / F 25 has received a packet, or receives an interrupt from the network I / F 25 to detect that the packet has been received (S210). .

  The activation determination unit 41 analyzes the received packet (S220). For this analysis, data in the “data” field of the TCP packet is used. The activation determination unit 41 determines that the application 2 needs to be activated when data in the “data” field is registered in the setting information stored in the nonvolatile memory 28.

  Even when the setting information on the controller is required for packet analysis, the power can be reduced in the main body of the image forming apparatus 100 because the analysis can be performed with power supplied only to the memory block 1.

  If it is not necessary to start the application 2 (Yes in S230), the application 1 processes the packet (S240). This process is a process that does not start the engine unit 12, and is, for example, a response to an inquiry about whether or not the PC is started.

  If the application 2 needs to be activated (No in S230), the application 1 executes the procedure for returning to the normal mode described with reference to FIG. 8 (S250).

[Storage structure of the data buffer 36]
The storage structure of the data buffer 36 will be described in detail with reference to FIG. FIG. 10 is an example of a diagram schematically illustrating the data buffer 36. In FIG. 10A, the data buffer 36 is divided for each byte.

  The data buffer 36 is accessed asynchronously by the physical driver 35, the protocol stack 1, and the virtual driver I / F 38, respectively. Here, if the physical driver 35 freely records the packet in the data buffer 36, the protocol stack 1 and the virtual driver I / F 38 may overwrite the packet before reading it from the data buffer 36. Conversely, the protocol stack 1 and the virtual driver I / F 38 may reread the same packet from the data buffer 36. Therefore, in this embodiment, the physical driver 35, the protocol stack 1, and the virtual driver I / F 38 can access the data buffer 36 asynchronously using pointers.

  In FIG. 10A, the pointer 1 is used by the physical driver 35, the pointer 2 is used by the protocol stack 1, and the pointer 3 is used by the virtual driver I / F 38. The pointers 1 to 3 move from the right to the left of the data buffer 36, and again move to the right end when they reach the left end. The address indicated by the pointers 1 to 3 can be referred to by the physical driver 35, the protocol stack 1, and the virtual driver I / F 38 as in the data buffer 36.

  FIG. 10B shows the pointers 1 to 3 in the initial state. The initial state is a state in which no packet is stored in the data buffer 36. For example, the initial state is immediately after the image forming apparatus 100 is activated. In the initial state, the pointers 1 to 3 indicate the rightmost address of the data buffer 36.

  FIG. 11 is a diagram for explaining the pointer 1 when the physical driver 35 writes a packet to the data buffer 36. When the physical driver 35 acquires a packet received by the network I / F 25, the physical driver 35 accumulates one byte at a time in the data buffer 36, and moves the pointer 1 to the left by one byte. Therefore, no packet is stored yet on the address pointed to by the pointer 1, and the pointer 1 indicates an empty block for storing the next packet.

  The physical driver 35 moves the pointer 1 to the left every time one byte of the packet is stored, but if the pointer 3 is overtaken, the packet that is not read by the virtual driver I / F 38 is overwritten. Therefore, the pointer 1 stops when it overlaps the pointer 3, and the physical driver 35 does not store the packet in the data buffer 36 until the pointer 3 moves to the left again. That is, the pointer 1 does not move to the left beyond the pointer 3. Since the pointer 2 is positioned on the left side of the pointer 3, it is not necessary to consider that the pointer 1 exceeds the pointer 2.

  FIG. 12A is a diagram for explaining the pointer 2 when the protocol stack 1 reads a packet from the data buffer 36. The protocol stack 1 reads the data on the pointer byte by byte until the pointer 2 overlaps the pointer 1. The pointer 2 stops reading the packet when it overlaps the pointer 1, and does not resume reading until the pointer 1 moves again. By doing so, the protocol stack 1 can prevent rereading of the already read packet.

  FIG. 12B is an example of a diagram for explaining the pointer 2 when the protocol stack 1 finishes analyzing the packet. The protocol stack 1 moves the pointer 3 to the position of the pointer 2 when a series of data analysis is completed. The series of data may be a single packet unit or a set unit of a plurality of packets for performing a certain process. When one packet unit is a series of data, the application 1 can respond after analyzing the data in the packet, so that the power saving mode can be maintained for a longer time. Further, when a group unit of a plurality of packets is a series of data, the power saving mode can be maintained for a longer time.

  While the virtual driver I / F 38 is stopped, the protocol stack 1 repeats the process of moving the pointer 3 to the position of the pointer 2 when a series of data analysis is completed. Therefore, while the virtual driver I / F 38 is stopped, the pointer 3 and the pointer 2 are often in a state indicating the same address.

  Here, in a process that requires the application 2 to be activated, if the application 1 discards the packet used for the determination, the application 2 needs to retransmit the packet to the other party. In order to make this retransmission unnecessary, the packet needs to be stored as it is in the data buffer 36 until the application 2 is activated.

  Therefore, the protocol stack 1 does not move the pointer 3 to the position of the pointer 2 when the activation determination unit 41 determines that the application 2 needs to be activated as a result of analyzing a series of data. That is, in this case, the pointer 3 indicates the head of the packet data that needs to be processed by the application 2.

  FIG. 13A is an example of a diagram illustrating the pointer 3 when the virtual driver I / F 38 reads a packet. When returning from the power saving mode to the normal mode, the virtual driver I / F 38 is activated. The virtual driver I / F 38 reads packets until the pointer 3 overlaps the pointer 1. When the pointer 3 overlaps the pointer 1, the virtual driver I / F 38 stops reading the packet. When the pointer 1 starts to move, the pointer 3 stops and restarts reading the packet from the position. Note that the protocol stack 1 is stopped during the normal mode.

  FIG. 13B is an example of a diagram illustrating the pointer 3 when the virtual driver I / F 38 is stopped by shifting to the power saving mode. When shifting to the power saving mode, the virtual driver I / F 38 receives a notification of the end of packet processing from the protocol stack 2. The virtual driver I / F 38 stops reading the packet from the data buffer 36 and moves the pointer 2 to the position of the pointer 3. That is, the position of the stopped pointer 2 is made to coincide with the position of the pointer 3.

  As described above, the image forming apparatus 100 according to the present embodiment uses the virtualization technology to partition the memory access range for each OS, and supplies power to only a part of the memory in the power saving mode. Therefore, it can be determined whether or not to shift to the normal mode in a state where power consumption is reduced and safely.

DESCRIPTION OF SYMBOLS 11 System management part 12 Engine unit part 13 Power supply unit part 15 Controller 21 Memory (Memory blocks 1-4)
22 CPU
23 Hard disk I / F
25 Network I / F
26 Engine I / F
28 Nonvolatile memory 33 Hypervisor 34 Hardware 35 Physical driver 36 Data buffer 37 Virtual driver 38 Virtual driver I / F
DESCRIPTION OF SYMBOLS 41 Starting determination part 42 Power saving mode transfer determination part 43 Power control part 44 Mode switching part 100 Image forming apparatus

JP 2008-181402 A

Claims (8)

A communication means for communicating via a network;
Data processing means for processing data using a memory block divided into a plurality of working memories;
A non-volatile memory for storing an application start condition, to which power is supplied when the data processing means is operated;
Virtualization means for virtualizing hardware for a plurality of OSs, allocating a first memory block to the first OS, and allocating a second memory block that does not overlap with the first memory block to the second OS;
And a power saving mode where only the first OS is started, the non-power saving mode and a mode switching means for switching said first OS and the second OS is started,
Power management means for supplying power only from the power source to the communication means, the data processing means, and the first memory block in the power saving mode;
First communication control means for receiving the data by controlling the communication means during startup of the first OS;
A data buffer provided in the first memory block for storing data received by the first communication control means during the power saving mode ;
The communication means between the power saving mode by referring to the activation condition based on the data received, whether activation is necessary for the application running on the second OS, the first on OS And an activation determination means for determining at
When the activation determination unit determines that the application needs to be activated, the mode switching unit switches from the power saving mode to the non-power saving mode, and activates the application and the second OS ,
A second communication control unit of the second OS started by the application reads data via a virtualized data reading unit that reads data from the data buffer and notifies the application;
An information processing apparatus characterized by that. Before SL application, the data to which the activation determination means determines that it is necessary to start the application, to retrieve from said second communication control means,
The information processing apparatus according to claim 1. The data reading unit specifies , by a pointer, an address at which the data determined by the activation determination unit that the application needs to be activated is stored .
The information processing apparatus according to claim 2. A first pointer indicating an address of the data buffer at which the activation determination means has completed reading data ;
A second pointer indicating the address of the data buffer has completed reading of the application is de over data,
The information processing apparatus according to claim 2, further comprising: a pointer operation unit that causes the second pointer to follow the first pointer in a power saving mode. When the activation determination means determines that the application needs to be activated,
The pointer operating means does not cause the second pointer to follow the first pointer;
The information processing apparatus according to claim 4. Each core of a multi-core CPU is, respectively executes the first OS and the second OS,
The information processing apparatus according to claim 1, wherein The information processing apparatus according to any one of claims 1 to 6 ,
An image forming apparatus comprising: a printer that forms an image on paper. A communication means for communicating via a network;
Data processing means for processing data using a memory block divided into a plurality of working memories;
An operation mode switching method executed by an information processing apparatus having a non-volatile memory for storing an activation condition of an application that is supplied with power when the data processing unit is operated,
The virtualization means virtualizes hardware for a plurality of OSs, assigns a first memory block to the first OS, and assigns a second memory block that does not overlap with the first memory block to the second OS. When,
The power management means supplying power from the power source only to the communication means, the data processing means, and the first memory block in the power saving mode;
For the first communication control means to control the communication means to receive data during startup of the first OS and to store the data received by the first communication control means during the power saving mode Storing in a data buffer provided in the first memory block;
Activation determining means, the communication means between the power saving mode by referring to the activation condition based on the data received, whether activation is necessary for the application running on the second OS, the Determining on the first OS;
When the activation determination unit determines that the application needs to be activated, the mode switching unit switches from the power saving mode to the non-power saving mode, and activates the application and the second OS ;
A second communication control unit of the second OS activated by the application reads data via a virtualized data reading unit that reads data from the data buffer and notifies the application; ,
An operation mode switching method.

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