JP2011257973A - Memory management method and memory management device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve effective utilization of a memory and to improve use efficiency of the memory without losing a real time property of a real time OS in a hybrid OS.SOLUTION: A memory management manager 110 performs memory management exception processing in exception and interruption of a memory management exception by using a program for controlling a MMU as hardware, and also performs allocation and removal of a real time OS logical space 101 under management of the MMU in input time of a memory reservation and release request 111 from a real time OS. A general-purpose OS kernel logical space 102 and a general-purpose process logical space 103 are treated as one real time OS task 109 of the real time OS logical space 101. In a memory management device 100, memory management of the real time OS is managed by a general-purpose OS by making a memory available under management of the general-purpose OS managed on the MMU, and scheduling is managed by the real time OS.

Description

  The present invention relates to a memory management method and a memory management device, and more particularly to a memory management method and a memory management device by each OS in a system having a hybrid OS in which a real-time OS (operating system) and a general-purpose OS operate on one computer. About.

  In recent years, a hybrid OS in which a plurality of operating systems (OS) operate on one computer has been used in various fields. Among hybrid OSes, systems that run real-time OSs and general-purpose OSs can use the rich resources of general-purpose OSs while taking advantage of the real-time characteristics of real-time OSs. It is getting used.

  In many of these hybrid OS systems, a real-time OS is used as a base OS, and a general-purpose OS is implemented as one task of the real-time OS, so as to ensure real-time performance. In this hybrid OS system, the general-purpose OS is executed as one of real-time tasks under the control of the real-time OS.

  However, in this hybrid OS system, when the process executed under the control of the general-purpose OS operates in cooperation with the real-time task, when the high priority of the real-time task is inherited, other than the processes operating in cooperation with each other The execution of real-time tasks may be hindered because processes are also executed with high priority.

  Therefore, in the task management device described in Patent Document 1, a task other than the operating system task that operates in cooperation with the process executed under the control of the general-purpose OS requests the operating system task for the cooperative operation and waits. When it is determined that the priority is higher than the priority of other tasks in the wait state, and it is determined that the priority is higher than the priority of other tasks in the wait state, the operating system task and the wait state By allowing the process that operates in cooperation with other tasks to become inherited to the priority of the task that enters the waiting state, other processes other than the processes that operate under the control of the general-purpose OS in cooperation with the real-time task are high. It is designed to prevent execution with priority.

JP 2005-234658 A

  However, in the task management device described in Patent Document 1, regarding memory management, the memory used by the real-time OS and the memory used by the general-purpose OS are generally separated when the hybrid OS is booted (started up). Cannot be used effectively. This will be described with reference to FIG.

  FIG. 8 shows an example of a memory map being executed in the hybrid OS. In the figure, when the hybrid OS is booted (started up), the memory area 801 managed by the general-purpose OS and the memory area 803 managed by the real-time OS are completely separated. In addition, the memory area 801 managed by the general-purpose OS is a main memory, and it is assumed that there is a page-unit memory free area 802. On the other hand, the memory 803 managed by the real-time OS includes a part of main memory and an I / O (input / output) area. Further, it is assumed that the boot-time free memory pool 804 is already used in the memory 803 managed by the real-time OS.

  At this time, if a memory allocation request occurs in the real-time OS, the request ends in failure even though there is a memory area that is not used in the memory area 803 managed by the real-time OS, and the memory cannot be used effectively. .

  In the conventional memory management method, for example, the general-purpose OS performs memory management using an MMU (Memory Management Unit), whereas the memory management of the real-time OS does not use the MMU. If the release is repeated, memory fragmentation occurs, and the memory utilization efficiency is greatly reduced. This will be described with reference to FIG.

  FIG. 9 shows fragmentation when a real-time OS is executed by a conventional memory management method. In the figure, a memory area 900 managed by the real-time OS is composed of a boot-time allocation memory 901 allocated at boot time and a boot-time free memory pool 902. The real-time OS processes memory allocation / release requests that occur during execution. The memory allocation request is allocated from the free memory pool 902 at boot time. Here, if memory allocation and memory release are repeated, fragmentation occurs in the free memory area 903 of the boot-time free memory pool 902, and usage efficiency is greatly reduced.

  The present invention has been made in view of the above points. In a hybrid OS in which both a real-time OS and a general-purpose OS operate on an architecture having an MMU, the memory management of the real-time OS that does not support the MMU is managed by the MMU. Memory management method and memory management that enable effective use of the memory without losing the real-time property of the real-time OS by making the memory under the management of the general-purpose OS available. An object is to provide an apparatus.

  In order to achieve the above object, a memory management method of the present invention includes a scheduling management unit and one or more first operating systems that do not support a memory management device as a base operating system, together with the first operating system. A first step in which the second operating system creates a logical space of the first operating system after booting one or more second operating systems that operate and perform memory management using the memory management device; The second operating system secures a physical memory area in the logical space of the created first operating system, and the physical memory area secured in the second step includes the first Boot the operating system A third step of operating the memory management device and then passing control to the first operating system; and a first operating system to which control is passed in the third step initializes the second operating system A fourth step of registering the system as a task of the first operating system; a fifth step of starting the scheduler by the first operating system; and a primary interrupt processing means for determining whether the interrupt is a memory management exception or other It is determined whether it is an interrupt / exception. If it is a memory management exception, the second operating system processes the memory management exception, and if it is any other interrupt / exception, it causes the first operating system to process the other interrupt / exception. The sixth step of sorting and the first When a memory allocation / release request is generated in the operating system, the memory allocation / release request is supplied to the second operating system, and the memory is allocated / released under the management of the memory management device by the second operating system. And a seventh step for performing the process.

  In order to achieve the above object, according to the memory management method of the present invention, in the second step, when the memory area of the first operating system is created by the memory management device, the logic of the first operating system is The memory page corresponding to the space is configured only by an accessible real space memory area.

  In order to achieve the above object, a memory management device of the present invention includes a scheduling management unit, one or more first operating systems that do not support the memory management device, and a base operating system based on the first operating system. One or more systems that are implemented as a task of the first operating system and operate together with the first operating system, and that manage the memory of itself and the first operating system using the memory management device, respectively. The second operating system determines whether the interrupt is a memory management exception or another interrupt / exception, and if it is a memory management exception, causes the second operating system to process the memory management exception, and if it is another interrupt / exception, First operation Primary interrupt processing means for distributing other interrupts / exceptions to the operating system, and when a memory allocation / release request occurs in the first operating system, the memory allocation / release request is issued to the second operating system. And a memory securing / release request processing means for supplying the system and performing memory securing / release processing under the control of the memory management device by the second operating system.

  In order to achieve the above object, the memory management device of the present invention is configured such that when the second operating system creates a memory area of the first operating system by the memory management device, The memory page corresponding to the logical space is configured only by an accessible real space memory area.

  According to the present invention, the scheduling is managed by the first operating system and the memory management is managed by the second operating system, so that the memory management of the real-time OS that is the first operating system is managed by the MMU. By making the memory under the management of the general-purpose OS that is the second operating system available, the memory can be effectively used without losing the real-time property of the real-time OS.

  In addition, according to the present invention, the memory allocation / release request is processed by the memory management manager in the general-purpose OS kernel logical space, and the memory is in units of pages under MMU management. Since empty page areas can also be allocated as continuous logical spaces, the memory utilization efficiency can be greatly improved.

It is a figure which shows the structure of one Embodiment of the memory management apparatus of this invention. It is a figure which shows the structure of an example of a general hybrid OS. It is a figure which shows the memory map by the conventional memory management method, and the memory map by the memory management method and memory management apparatus of this invention. It is a figure explaining one Embodiment of the memory management method and memory management apparatus of this invention. It is a flowchart for operation | movement description at the time of boot of one Embodiment of the memory management method of this invention. 6 is a flowchart for explaining operations during interrupt / exception processing according to an embodiment of the memory management method of the present invention; 6 is a flowchart for explaining an operation at the time of memory reservation / release according to an embodiment of the memory management method of the present invention; It is a figure which shows an example of the memory map in execution of hybrid OS by the conventional memory management method. It is a figure which shows an example of the fragmentation at the time of real-time OS execution by the conventional memory management method.

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows the configuration of an embodiment of a memory management device according to the present invention. As shown in the figure, the memory management device 100 includes a real-time OS logical space 101, a general-purpose OS kernel logical space 102, and a general-purpose OS process logical space 103 as a hybrid OS system logical memory space. In addition, a primary interrupt processing manager 104 that performs primary processing of hardware interrupt and exception processing and determines whether the interrupt is a memory management exception or not is provided. The primary interrupt processing manager 104 distributes memory management exceptions so that the general-purpose OS kernel processes them, and other interrupts and exceptions are processed by the real-time OS kernel 105. The primary interrupt processing manager 104 constitutes primary interrupt processing means of the present invention.

  The real-time OS logical space 101 has a configuration in which a real-time OS kernel 105 serves as a base OS and a real-time OS task 107 is under scheduling management of the real-time OS scheduler 108. In the real-time OS logical space 101, the real-time OS kernel 105 is provided with a real-time OS interrupt handler 106 for performing real-time interrupt / exception processing at the time of exception / interrupt other than the memory management exception. The real-time OS logical space 101 is a memory space of a real-time OS that does not support an MMU (Memory Management Unit).

  On the other hand, a memory management manager 110 is provided in the general-purpose OS kernel logical space 102. The memory management manager 110 is a program that controls the hardware MMU, and performs memory management exception processing at the time of memory management exception exception / interruption, and is also under MMU management when the memory allocation / release request 111 is input from the real-time OS. Then, the real-time OS logical space 101 is allocated and deleted. The above-mentioned allocation / deletion function of the real-time OS logical space 101 of the memory management manager 110 constitutes the memory allocation / release request processing means of the present invention.

  The general-purpose OS kernel logical space 102 and the general-purpose OS process logical space 103 constitute a real-time OS task 109. Accordingly, the real-time OS task 109 has a configuration different from that of a normal native task such as the real-time OS task 107, but is the same real-time OS task 107 as the real-time OS task 107 when viewed from the real-time OS kernel 105. That is, the general-purpose OS kernel logical space 102 and the general-purpose OS process logical space 103 are handled as one task of the real-time OS logical space 101. The memory space of the real-time OS task 109 is a memory space of a general-purpose OS that supports MMU. The scheduling function is managed by the real-time OS kernel 105 in this embodiment.

  Here, the configuration of a general hybrid OS will be described with reference to FIGS. FIG. 2 is a diagram showing a configuration of an example of a general hybrid OS, and FIG. 3 is a diagram showing a memory map by a conventional memory management method, and a memory map by a memory management method and a memory management device of the present invention. It is.

  As shown in FIG. 2, a general hybrid OS 200 has a real-time OS kernel 201 as a base OS, and a real-time OS task 202, a general-purpose OS kernel 204, and a general-purpose OS process 205 are scheduled as a real-time OS task 203. Is under control.

  As shown in FIG. 3A, the memory map at this time includes a memory area 301 managed by the real-time OS and a memory area 302 managed by the general-purpose OS. The memory area 302 managed by the general-purpose OS is stored in the main memory 305. On the other hand, the memory area 301 managed by the real-time OS is in the I / O area 303 and a part 304 of the main memory. That is, the main memory is completely divided into a main memory part 304 managed by the real-time OS and a main memory part 305 managed by the general-purpose OS. In general, the main memory portions 304 and 305 managed by each OS are separated at the time of booting, and each OS is booted.

  Further, when the real-time OS is executed, memory management by the MMU or the like is not performed, and everything is managed by real memory. When the real-time OS task or the real-time OS kernel issues a memory reservation request, the real-time OS allocates memory from the managed memory area 301. For this reason, as described with reference to FIG. 8, even if there is an empty memory (802 in FIG. 8) in the memory area 302 managed by the general-purpose OS in the above case, it cannot be used. In addition, since the MMU is not used, if the memory reservation and release are repeated, memory fragmentation occurs as described with reference to FIG. 9, and the memory utilization efficiency is significantly reduced.

  Therefore, in this embodiment, in order to solve the above-described problem, the memory under the management of the general-purpose OS managed by the MMU can be used for the memory management of the real-time OS that does not support the MMU. The memory can be effectively used without losing the real-time property of the real-time OS, and the memory utilization efficiency is improved. This outline will be described with reference to FIGS.

  The task as the execution unit in the present embodiment is implemented in the same manner as a general hybrid OS. However, in this embodiment, memory management is performed by the MMU during execution of the real-time OS and the general-purpose OS. As shown in FIG. 1, the logical memory space includes the real-time OS logical space 101, the general-purpose OS kernel. It consists of a logical space 102 and a general-purpose OS process logical space 103.

  In this embodiment, as shown in FIG. 3B, the memory map shares the main memory 308 as a memory area 306 managed by the general-purpose OS and the real-time OS, and is dynamically managed by the general-purpose OS and the real-time OS. To do. The I / O area 309 is a memory area 307 managed by the real-time OS and is managed by the real-time OS.

  Next, details of the memory management of the present embodiment will be described with reference to FIG. FIG. 4 is a diagram for explaining an embodiment of a memory management method according to the present invention.

  In FIG. 4, a general-purpose OS process logical space 401 (corresponding to the general-purpose OS process logical space 103 in FIG. 1) is assigned a segment management table 403 composed of segments such as programs, data, and stacks by a general-purpose OS kernel. Each segment in the segment management table 403 is associated with a physical address by the page management table 405, and corresponds to the actual memory area 407 (the memory area 306 managed by the general-purpose OS and real-time OS in FIG. 3B). ) Indicates which page you are referring to.

  On the other hand, the real-time OS logical space 402 (corresponding to the real-time OS logical space 101 in FIG. 1) is assigned with a kernel of each real-time OS, each task, and an I / O area. A segment management table 404 composed of segments such as areas is allocated.

  Each segment of the segment management table 404 is associated with a physical address by the page management table 406, which page in the actual memory area 407 is referred to, or the memory area 408 (FIG. 3B). Which page in the memory area 307 managed by the real-time OS is referred to.

  The memory management for the real-time OS logical space 402 is a general-purpose OS process in that a memory management configuration in which a memory exception such as a page violation does not occur because a physical space corresponding to the logical space always exists in the memory. This is different from the memory management for the logical space 401.

  Next, the operation of the memory management method in this embodiment will be described.

  First, the boot operation will be described with reference to FIG. FIG. 5 shows a flowchart for explaining the operation at the time of booting of an embodiment of the memory management method according to the present invention.

  First, the boot loader boots the general-purpose OS kernel 204 (step S101). The general-purpose OS kernel 204 includes the memory management manager 110 in its logical space as indicated by 102 in FIG. 1, and the general-purpose OS kernel 204 initializes itself by the memory management manager by the above boot (step S102). ). By this initialization, the memory management manager 110 in the general-purpose OS kernel logical space 102 creates a page management table 405 corresponding to the physical memory and registers it in the free list.

  Next, the general-purpose OS kernel 204 creates the real-time OS logical space 101 (402) (step S103). Specifically, the general-purpose OS kernel 204 creates a segment management table 404 composed of segments of the kernel, task free area, and I / O area of the real-time OS logical space 402, and A page management table 406 corresponding to the segment is created.

  Next, the general-purpose OS kernel program loaded into the general-purpose OS kernel logical space 102 stores physical memory areas 407 and 408 required for the real-time OS logical space 101 (402) from the previously created page free list. It is secured (step S104), and the physical address of the memory area is registered in the page management table. At this time, the real-time OS logical space 101 (402) required by the real-time OS is all allocated to the memory area 407, which is an actual physical memory.

  That is, in steps S103 and S104, when the memory area of the real-time OS logical space 101 (402) is created by the general-purpose OS memory management manager 110, the memory page corresponding to the real-time OS logical space 101 (402) can be accessed. By configuring only in the memory area 407 of the space, the occurrence of a memory exception during execution of the real-time OS is eliminated.

  As for interrupt processing, an interrupt vector and the like are set so that the primary interrupt processing manager 104 in FIG. 1 processes all interrupts. The interrupt processing manager 104 is loaded as a part of the general-purpose OS, and is arranged in a space where interrupt processing can be executed according to the system architecture.

  Subsequently, the general-purpose OS kernel program boots the real-time OS in the memory areas 407 and 408 of the secured real-time OS logical space 101 (402) (step S105), and then activates the function of the MMU (step S106). Thereafter, the general-purpose OS kernel program passes control to the real-time OS (step S107). As a result, the real-time OS starts execution of the program in the prepared real-time OS logical space 101 (402).

  That is, the real-time OS kernel 105, which is a program loaded in the real-time OS logical space 101 (402), first initializes itself, and the general-purpose OS (the general-purpose OS kernel logical space 102 and the general-purpose OS process logical space 103) is loaded. It is registered as its own task (ie, real-time OS task 109, 203) (step S108). Subsequently, the real-time OS kernel 105 starts the real-time OS scheduler 108 (step S109).

  When the real-time OS scheduler 108 is started, control is transferred to the real-time OS task 109 (203), whereby the general-purpose OS kernel 204 in the general-purpose OS kernel logical space 102 follows a predetermined procedure and a general-purpose OS process 205 such as an initialization process. Generate and execute.

  Next, the interrupt / exception processing operation of this embodiment will be described with reference to FIG. FIG. 6 is a flowchart for explaining the operation at the time of interrupt / exception processing according to an embodiment of the memory management method of the present invention.

  When an interrupt / exception occurs, processing is first passed to the primary interrupt processing manager 104 in accordance with a registered interrupt vector or the like. Thus, the primary interrupt processing manager 104 performs common interrupt processing necessary for the system architecture (step S201). Next, the primary interrupt processing manager 104 determines whether or not the interrupt is a memory management exception (step S202).

  If it is a memory management exception (yes in step S202), the primary interrupt processing manager 104 calls the memory management exception processing of the general-purpose OS (step S203), and the memory management manager 110 in the general-purpose OS kernel performs the memory management exception processing. This is performed (step S204). The memory management exception processing here is processing such as handling of unauthorized processing such as page violation, and securing of memory of the general-purpose OS process 103 by a demand paging system on the general-purpose OS side. When the real-time OS is executed, since all the logical spaces are allocated to the physical space at the time of boot initialization, basically no memory management exception occurs.

  If it is not a memory management exception (No in step S202), the primary interrupt processing manager 104 calls the interrupt / exception processing of the real-time OS (step S205). Control is transferred to the interrupt handler 106 by calling the interrupt / exception process of the real-time OS. After the process of step S204 or S205, the primary interrupt process manager 104 finally performs a common interrupt end process (step S206) and ends the interrupt.

  Finally, a memory securing / releasing operation during execution of the real-time OS according to the present embodiment will be described with reference to FIG. FIG. 7 is a flowchart for explaining the operation at the time of memory reservation / release in one embodiment of the memory management method according to the present invention.

  When the real-time OS (that is, the real-time OS task 203 or the real-time OS kernel 204) generates a memory reservation / release request (step S301), the real-time OS kernel 203 generates a memory reservation / release request (step S302). The memory allocation / release request 111 is transferred to the memory management manager 110 in the OS kernel logical space 102 (step S303). For this transfer, a common memory of the real-time OS kernel 105 and the general-purpose OS kernel 102 is used.

  The memory management manager 110 allocates and deletes the real-time OS logical space 101 (402) based on the memory allocation / release request (step S304). Next, the memory management manager 110 determines whether the memory allocation / release request is a memory allocation request (step S305). In the case of deletion (“deletion” in step S305), the memory management manager 110 invalidates the used page management table 406 and adds the corresponding memory area 407 to the free memory list (step S306).

  On the other hand, in the case of a memory reservation request (“Reserve” in step S305), the memory management manager 110 determines whether or not the free memory list in the main memory being managed has a free physical memory amount requested for memory reservation. Thus, it is determined whether or not the memory can be secured (step S307). If there is no free memory list and the memory cannot be secured (No in step S307), an error end process is performed and the process ends (step S309).

  On the other hand, if the free memory list is free and the memory can be secured (yes in step S307), the memory management manager 110 allocates physical memory to the real-time OS logical space 101 (step S308). Specifically, the page management table 406 for the corresponding segment is created, the secured physical address is written in the memory area 407, and the process is terminated.

  According to the memory management method and memory management device of the present embodiment described above, a hybrid in which a real-time OS is used as a base system, the general-purpose OS is implemented as a task of the real-time OS, and the real-time OS and the general-purpose OS operate together. In the OS, when there is a memory allocation request from the real-time OS task 203 or the real-time OS kernel 204, the memory management manager 110 of the general-purpose OS kernel logical space 102 determines whether or not the memory can be allocated, and there is a free area. In this case, since the real-time OS logical space 101 is allocated, the memory can be effectively used. In other words, in the present embodiment, the memory under the management of the general-purpose OS managed by the MMU can be used for the memory management of the real-time OS, as shown in FIG. Since the main memory 308, which is a physical memory, is shared as the memory area 306 managed by the real-time OS, and the memory can be secured and released as necessary, the memory can be used effectively.

  Further, according to the memory management method of the present embodiment, the memory allocation / release request is processed by the memory management manager 110 of the general-purpose OS kernel logical space 102, and the memory is in units of pages under MMU management. Fragmentation as shown does not occur. Also, since discontinuous empty page areas can be allocated as a continuous logical space, the memory utilization efficiency can be greatly improved.

  Furthermore, in this embodiment, since physical memory is always allocated to the real-time OS logical space 101, it is possible to prevent deterioration of real-time performance due to memory management exception processing or the like.

  The present invention is not limited to the above-described embodiment. For example, in the above-described embodiment, one real-time OS (real-time OS kernel and real-time OS task) that does not support the MMU on the architecture having the MMU. And one general-purpose OS that supports MMU (general-purpose OS kernel and general-purpose OS process) are described as being applied to a hybrid OS. The present invention can be applied to any hybrid OS that can operate simultaneously.

  The present invention also includes a memory management program that causes a computer to execute the processing of each step in the flowcharts shown in FIGS. In this case, the memory management program may be loaded from a recorded recording medium into the computer, or may be distributed via a communication network and loaded into the computer.

100 Memory management device 101, 402 Real-time OS logical space 102 General-purpose OS kernel logical space 103, 401 General-purpose OS process logical space 104 Primary interrupt processing manager 105, 201 Real-time OS kernel 106 Real-time OS interrupt handler 107, 202 Real-time OS task 108 Real-time OS Scheduler 109, 203 Real-time OS task 110 Memory management manager 111 Memory reservation / release request 200 General hybrid OS
204 General-purpose OS kernel 205 General-purpose OS processes 301 and 307 Memory area 302 managed by the real-time OS Memory area 306 managed by the general-purpose OS Memory areas 403 and 404 segment management tables 405 and 406 page management tables managed by the general-purpose OS and the real-time OS 407 Memory area (memory area managed by general-purpose OS and real-time OS)
408 Memory area (I / O area)

Claims (4)

One or more first operating systems that have scheduling management means and that do not support the memory management device operate as the base operating system together with the first operating system, and perform memory management using the memory management device. A first step of creating a logical space of the first operating system after the booting of the one or more second operating systems to perform;
A second step in which the second operating system secures a physical memory area in the logical space of the created first operating system;
Booting the first operating system into the physical memory area reserved in the second step, operating the memory management device, and then passing control to the first operating system Steps,
A fourth step in which the first operating system to which control is passed in the third step registers the second operating system as one task of the first operating system after initializing itself;
A fifth step in which the first operating system starts a scheduler;
The primary interrupt processing means determines whether the interrupt is a memory management exception or another interrupt / exception, and when the interrupt is the memory management exception, causes the second operating system to process the memory management exception, and A sixth step of allocating the first operating system to handle the other interrupt / exception when an exception occurs;
When a memory allocation / release request is generated in the first operating system, the memory allocation / release request is supplied to the second operating system, and the management of the memory management device is performed by the second operating system. A seventh step for performing memory allocation / release processing below;
A memory management method.   The second step is a real space memory area that can access a memory page corresponding to the logical space of the first operating system when the memory management device creates the memory area of the first operating system. The memory management method according to claim 1, wherein only the memory is configured. One or more first operating systems having scheduling management means and not supporting a memory management device;
The first operating system is a base operating system, is implemented as a task of the first operating system, operates together with the first operating system, and uses the memory management device to identify itself and the first operating system. One or more second operating systems each performing memory management of the operating systems of
It is determined whether the interrupt is a memory management exception or another interrupt / exception. If the interrupt is the memory management exception, the second operating system is caused to process the memory management exception. If the interrupt is another interrupt / exception, the first interrupt is detected. Primary interrupt processing means for distributing the operating system to the other interrupt / exception processing;
When a memory allocation / release request is generated in the first operating system, the memory allocation / release request is supplied to the second operating system, and the management of the memory management device is performed by the second operating system. Memory allocation / release request processing means for performing memory allocation / release processing below,
A memory management device comprising:   When the second operating system creates the memory area of the first operating system by the memory management device, the memory area of the real space that can access the memory page corresponding to the logical space of the first operating system 4. The memory management device according to claim 3, wherein the memory management device is configured only by the above.

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