JPH06214813A - Virtual computer display control system - Google Patents

Abstract

PURPOSE:To provide a display control part emulation system whose performance can be prevented from lowering even for the application program(AP) of a target machine with different VRAM address constitution by providing the virtual graphic memory (virtual VRAM) area of the target machine on the memory of a base machine. CONSTITUTION:The base machine is equipped with a memory managing mechanism which performs the mapping of a physical memory map on a logical memory map. The logical memory map compatible with the memory map of the target machine is provided on the memory 6 of the base machine by the memory managing mechanism, and an OS 14 and the AP 13 for target machine are stored in the memory map. Software to transfer data while performing the conversion of address constitution from a VRAM area on the logical memory map compatible with the target machine to that of the base machine is loaded on the base machine to efficiently convert the VRAM address of the target machine with different constitution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a virtual computer emulation system for maintaining compatibility of application programs and the like between a plurality of different models having different graphic memory address configurations in personal computers, workstations and the like.

[0002]

2. Description of the Related Art In a personal computer (hereinafter abbreviated as a personal computer), a workstation, or the like, data to be displayed on a display device is stored in a VRAM, and the display controller reads the data from the VRAM and displays it on the display device.

On the other hand, there are many different architectures for personal computers and workstations, and each architecture has its own display device. Therefore, the display by the AP developed on one architecture cannot be normally displayed on the other different architecture and is incompatible.

Conventionally, in order to solve the above problems, the following two methods have been adopted.

One is to port an AP operating on one architecture to another different architecture. A normal display is obtained by modifying the display part in the AP according to the specifications of the display device of the architecture to be ported.

The other is to maintain compatibility by emulating models of different architectures on models of one architecture.

As a method of emulating the display control unit hardware of the target machine, there is a method of using the display control unit of the base machine to perform emulation within the range of the display function of the base machine.

Further, as described in JP-A-3-33937,
There is a method of performing emulation by adding display control unit hardware of a target machine that directly accesses the base machine from the AP.

[0009]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the emulation method according to No. 6, it is necessary to mount the display control unit hardware of the target machine on the base machine, and the AP cannot be operated on a personal computer having the same architecture as the base machine without this.

Therefore, in order to operate the AP of the target machine on all personal computers or workstations having the same architecture as the base machine,
It is necessary to emulate the display control unit of the target machine by the display control unit of the base machine, and to emulate the functions that cannot be realized by the hardware of the base machine by software.

However, in the above method, the VR corresponding to the display position on the screen of the display device in the target machine is corresponded.
If the AM address configuration is different from the base machine,
Performance will be reduced due to the need for address translation by software.

An object of the present invention is to improve the compatibility of a virtual machine with a target machine on the base machine without making a significant change to the hardware of the base machine, and to use a target machine AP having a different VRAM address configuration. To provide a display control unit emulation method with less performance degradation.

[0013]

In order to achieve the above object, the hardware configuration of the base machine is not particularly changed, provided that the base machine has a memory management mechanism for mapping a physical memory map to a logical memory map. Be prepared.

The memory management mechanism realizes a logical memory map compatible with the memory map of the target machine on the memory of the base machine, and stores the OS and AP for the target machine.

In order to efficiently convert the VRAM address of the target machine whose VRAM address differs from that of the base machine, the VRAM address of the base machine is changed from the VARAM area on the logical memory map compatible with the target machine.
The base machine is equipped with software for transferring data while converting the address configuration to the area.

[0016]

The virtual machine monitor for controlling the virtual machine is provided with the operation modes of the base machine mode and the target machine mode. The virtual machine monitor does nothing in base machine mode. When transitioning from the base machine mode to the target machine mode, the virtual machine monitor uses the target machine OS and AP stored in the area not used by the base machine OS to create a logical memory compatible with the target machine by using the memory management mechanism. Map to a region.

In the present invention, the VRA of the base machine is used.
Map the M area to the virtual VRAM area set on the memory instead of the VRAM area of the target machine,
It is prohibited to directly access the VRAM area of the base machine from the AP. The AP for the target machine uses the virtual VRAM with the VR having the same address configuration as the target machine.
It can be accessed as AM. However, since this alone does not store data in the VRAM area of the base machine, nothing is displayed on the display device. Therefore, from the VRAM area for the target machine to the VRA for the base machine
The software for transferring the data for one screen while converting the address structure to the M area is called by using a timer interrupt or the like to transfer the data. As a result, it is possible to emulate the display function without mounting the display control section of the target machine.

Further, in the present invention, the OS of the target machine can be operated in the same manner as the AP,
Part of the BIOS function is O for the target machine
By causing S to process, the number of times of processing by emulation is reduced, and the performance degradation of AP is reduced.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. Reference numeral 1 is a CPU having a memory management mechanism, 2 is an address bus, 3 is a data bus, 4 is an interrupt control unit for controlling timer interrupts, and 5 is a virtual graphic memory for storing display data of a target machine AP. VRAM), 6 is the main memory of the base machine, 7 is the graphic memory (VRAM) of the base machine, and 8 is V
Display control unit hardware of the base machine for displaying the data stored in the RAM 7 on the CRT 9, 1
Reference numeral 0 is an I / O control unit that interfaces with the external storage device 11 and the keyboard 12. AP13 for target machine, OS14 for target machine,
The virtual machine monitor 15 and the base machine OS 16 are stored in the main memory 6.

The virtual machine monitor 15 uses the memory management mechanism to form a logical memory map compatible with the target machine and activates the AP 13 for the target machine. Also,
Since a part of the BIOS function is processed by the target machine OS 14, the virtual machine monitor 1
5 only needs to perform emulation such as I / O with hardware and interrupt processing.

FIG. 2 shows an example in which the address configurations of the graphic memory of the base machine and the target machine are different. FIG. 2A is an address map of the VRAM 7, which is referred to by a relative address from the beginning of the area. Each data has a size of 8 bits, and each bit of the data corresponds to one dot on the screen. 2B and 2C are examples of the address configuration of the graphic memory of the base machine and the target machine, respectively. In the base machine, the data of the graphic memory is displayed horizontally on the screen.
The target machine shall display vertically. Therefore, the display positions of the data at addresses 0, 1, 2 in the target machine graphic memory are the addresses 0, 80, 1 in the base machine graphic memory.
This corresponds to the display position of 60 data.

The target machine AP 13 is a virtual VRA.
Data is stored in M5 according to the address configuration shown in FIG. When transferring data from the virtual VRAM 5 to the VRAM 7, the data is transferred while performing address conversion so as to correspond to the address configuration shown in FIG. In the example of FIG. 2, address 0 of the virtual VRAM 5
The data stored in 1 and 2 may be transferred to the addresses 0, 80 and 160 of the VRAM 7.

FIG. 3 shows an example of processing of the above memory transfer by a timer interrupt. AP13 for target machine
In order to transfer the display data from the virtual VRAM 5 to the VRAM 7 at a certain fixed time interval during execution of, the interrupt control unit 4 causes the timer interrupt 31 to be generated.
When the timer interrupt 31 occurs, the virtual computer monitor 1
Reference numeral 5 activates the data transfer routine 33 via the internal interrupt processing 32. The data transfer routine 33 uses the virtual V
The display data stored in the RAM 5 is sequentially read and VR
The corresponding address on the AM 7 is obtained, the display data is stored, and after the transfer for one screen is completed, the process returns to the target machine AP 13. Although the execution speed of the target machine AP 13 is slightly reduced by calling the data transfer routine 33 by the timer interrupt 31, it is a relatively simple process, and the compatibility can be improved without major modification of hardware and software. .

FIG. 4 is a memory map of one embodiment of the present invention. FIG. 4A is a physical memory map, and FIG. 4B is a logical memory map. It is assumed that both the target machine OS 14 and the base machine OS 16 can manage a memory of up to 1 megabyte, and the base machine has a memory of 2 megabytes or more. OS for base machine from physical memory address 0 to 1 megabyte
16 areas, OS 14 for target machine and AP
13 is stored in a physical memory address higher than 1 megabyte. The virtual machine monitor 15 is divided into a resident section 42 that actually controls the virtual machine such as emulation during execution of the target machine AP 13 and a loader section that performs mapping of the logical memory and loading of the resident section 42 at startup. Is stored in a physical memory address higher than 1 megabyte, and the loader section is the base machine OS16.
It is stored in the area of. When the virtual machine is executed, the physical memory map is mapped to the logical memory map shown in FIG. 4B, and the target machine AP is operated. Also,
The resident unit 42 of the virtual machine monitor 15 makes the physical address and the logical address the same so that the resident unit 42 can operate regardless of the presence or absence of memory mapping.

FIG. 5 shows another embodiment of the present invention. V that detects access to the virtual VRAM 5 in the base machine
A RAM access detector is provided and AP for target machine
Each time the access from 13 to the virtual VRAM 5 is detected, the data transfer routine 33 is activated to transfer the display data. In the present embodiment, when the display contents of the screen are not changed, the data transfer is stopped and the AP for the target machine is
13 It is possible to reduce performance degradation during execution.

FIG. 6 shows another embodiment of the present invention. Display BIOS from AP13 for target machine
By the call, the virtual machine monitor 15 emulates the display BIOS through the interrupt processing routine, and then activates the data transfer routine 33 to start the virtual VRAM.
The data transfer from 5 to the VRAM 7 is executed, and the process returns to the AP for the target machine. In this embodiment, similarly to the above-mentioned another embodiment, since the display data is transferred only when the display content of the screen changes, the AP for the target machine is used.
The performance degradation of can be reduced.

[0028]

According to the present invention, it is possible to realize a virtual computer having high compatibility in display function without mounting the display control unit hardware of the target machine on the base machine. Even for target machines with different VRAM address configurations, display data from the AP is stored in the virtual VRAM, and data transfer to the VRAM and address configuration conversion are processed collectively for one screen for efficient emulation. Can be done
Performance degradation can be reduced.

Further, the virtual VRA of the display data is detected by the detection of the virtual VRAM access or the display BIOS call.
The transfer from M to VRAM can be activated to further reduce the performance degradation.

[Brief description of drawings]

FIG. 1 is a system configuration diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a difference in address configuration of a graphic memory between a base machine and a target machine according to the present invention.

FIG. 3 is a diagram showing a processing procedure of graphic data transfer in the present invention.

FIG. 4 is a diagram showing a memory map showing an embodiment of the present invention.

FIG. 5 is a system configuration diagram showing another embodiment of the present invention.

FIG. 6 is a diagram showing a processing procedure showing another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... CPU, 4 ... Interrupt control part, 5 ... Virtual graphic memory, 6 ... Main memory, 7 ... Graphic memory, 8 ... Display control part, 13 ... Target machine AP, 15 ... Virtual computer monitor program, 17 ... VRAM access Detector, 33 ... Data transfer routine.

Claims (4)

[Claims] 1. A different architecture (hereinafter referred to as "base machine") on one architecture model (hereinafter referred to as "base machine")
In a virtual machine provided with a virtual machine monitor program for operating an application program (hereinafter referred to as AP) developed on a target machine),
A virtual graphic memory (hereinafter referred to as virtual VRAM) area of the target machine is provided on the memory, and display data is transferred from the virtual VRAM to the graphic memory (hereinafter referred to as VRAM) of the base machine by the virtual computer monitor program. A virtual computer display control method characterized by collectively converting address configurations. 2. The virtual computer according to claim 1, wherein the virtual VR
A virtual computer display control method characterized in that display data transfer from AM to VRAM of a base machine is activated by a timer interrupt of hardware. 3. The virtual computer according to claim 1, wherein the virtual VR
Virtual VRAM from AP with AM access detection means
A virtual computer display control method characterized by activating display data transfer from the virtual VRAM to the VRAM of the base machine upon detection of access. 4. The virtual machine according to claim 1, wherein when the display function is emulated by the virtual machine monitor program, the virtual machine is moved from the virtual VRAM to the VRA of the base machine.
A virtual computer display control method characterized by activating display data transfer to M.