JPH04237336A - Program context control system - Google Patents

Abstract

PURPOSE:To store and restore register even extended register values by detecting the execution of a super-setting program in a sub-setting side context at the time of switching the context. CONSTITUTION:At the time of switching a context being executed by a super- setting program 22d in a task 22, an extending register storing/extending function 15 detects the switching and stores the register values of an extending register group 12 i a stack 22c and a sub-setting register storing/restoring function 13 stores the register values of a sub-setting register group 11 in a context storing area 22b. In the case of restoring the register values, the sub-setting register group 11 is restored from the area 22b by the means 13, the extending register storing/extending function 15 restores the extending register group 12 fromt the stack 22c.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a program context control system, and more particularly to a program context control system in a microprocessor that can operate programs of two different register sets in a mixed manner.

0002

2. Description of the Related Art Conventionally, a microprocessor capable of running programs for two different register sets in a mixed manner has only a context saving/restoring means for each register set. For example, Intel 80386
The /486 microprocessor allows programs that use a 16-bit register set and programs that use a 32-bit extended register set to run together, each using a 16-bit TSS (Task
State Segment) and 32-bit TS
However, when switching contexts during the operation of a program that uses a 32-bit extended register set under a 16-bit TSS, only the register values for the 16-bit register set are saved. Become(
(Refer to various 80386/486 manuals published by Intel).

0003

[Problems to be Solved by the Invention] In the conventional program context control method described above, when a context switch occurs while a superset program is running on a context on the subset side, only the contents of the subset are saved. Since only register values were used, there is a drawback that the superset program cannot operate correctly when the context is restarted.

[0004] Therefore, O
When using S (Operating System), superset programs cannot be freely used on the subset OS, and conversely, when superset programs are freely combined and used, the subset OS must be modified. It was necessary to make it compatible with superset context saving/restoring means.

[0005] This is one of the problems that makes it difficult to realize a multi-OS mechanism in which a plurality of subset OSs and superset OSes are operated in parallel on one microprocessor by taking advantage of the execution environments of two programs. It is one.

In view of the above-mentioned points, an object of the present invention is to detect execution of a superset program on a context on the subset side at the time of context switching, and to detect the execution of a superset program on the context of the subset side, and to detect the execution of a superset program on the context of the subset side, and to detect the execution of a superset program on the context of the subset side, and By making it possible to save and restore even register values, subset OS and superset programs can be freely used together, and multiple subset OS
An object of the present invention is to provide a program context control method that allows S and superset OS to operate in parallel on one microprocessor.

[0007]

[Means for Solving the Problems] The program context control method of the present invention provides a microprocessor that simultaneously provides an execution environment for programs with two register sets, one as a subset and the other as a superset, and enables mixed operation. Subset context saving/restoring means for saving and restoring register values for a subset corresponding to a subset; and superset context saving/restoring means for saving and restoring register values for a superset corresponding to a superset. , extended context saving/restoring means for detecting when a superset program is being executed on a context on the subset side and saving and restoring extended register values separately from the subset context saving/restoring means; have

[0008]

[Operation] In the program context control method of the present invention, the context saving/restoring means for subset saves and restores register values for the subset in correspondence with the subset, and the context saving/restoring means for superset saves and restores register values for the subset in correspondence with the superset. The extended context save/restore means detects when a superset program is being executed on the context of the subset, and separately from the subset context save/restore means. Save and restore extended register values.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a block diagram schematically showing a microprocessor to which a program context control method according to an embodiment of the present invention is applied. This microprocessor is a CPU (Central Process).
The main part thereof is composed of an input unit) 1 and a memory 2.

The CPU 1 has a subset register group 11 and an extended register group 12 expanded for supersets, and has a subset register save/restore function 13 as a function for storing register values at the time of context switching.
It has a superset register save/restore function 14. The subset register save/restore function 13 corresponds to a subset context save/restore means, and the superset register save/restore function 14 corresponds to a superset context save/restore means. Also, CPU
1 has an extension register save/restore function 15 as a microprogram that detects when the superset program 24d is operating on the context of the subset side and saves and restores the register values of the extension register group 12. The extension register save/restore function 15 corresponds to an extension context save/restore means.

[0012] On the memory 2, there are an OS 21 (hereinafter referred to as subset OS) that targets a subset program 22a, a task 22 that runs on the subset OS 21, and an OS that targets a superset program 24a. (hereinafter referred to as the superset OS) 23 and a task 24 running on the superset OS 23, the task execution environment is considered as a context, and the subset registers of the CPU 1 are saved when switching tasks or when an external interrupt occurs. /restore function 13, superset register save/restore function 14, and extended register save/restore function 15.

On the task 22, there is a subset program 22a that uses the subset register group 11, a context storage area 22b that stores the register values of the subset register group 11, and a stack 22c that stores the register values of the extension register group 12. and a superset program 22d that uses the subset register group 11 and the extension register group 12.

On the task 24, there is a superset program 24a that uses the subset register group 11 and the extension register group 12, and a context storage area 24b that saves the register values of the subset register group 11 and the extension register group 12. and a stack 24c.

Next, the operation of the program context control system of this embodiment configured as described above will be explained.

Subset program 2 on task 22
2a or the superset program 24a on the task 24, the subset register save/restore function 13 of the CPU 1
and superset register save/restore function 14,
A context storage area 22b and a context storage area 24b prepared by the subset OS 21 and the superset OS 23 for each task 22 and task 24
The range of each register set, that is, task 2
In the case of task 2, the register values of only the subset register group 11 are saved, and in the case of task 24, the register values of the subset register group 11 and the register values of the extended register group 12 are respectively saved. When restoring, the subset register save/restore function 13 and the superset register save/restore function 14 save the register values saved in the context save area 22b and the context save area 24b into the subset register group 11 and the subset register group 11. and are restored to the extension register group 12, respectively.

When the context is switched during the execution of the superset program 22d on the task 22, the extension register save/extension function 15 detects this and saves the register values of the extension register group 12 to the stack 22c. , the subset register save/restore function 13 saves the register values of the subset register group 11 in the context save area 22b. Conversely, when restoring, after the subset register saving/restoring function 13 restores the subset register group 11 from the context saving area 22b, the extension register saving/extending function 15 restores the extended register group 12 from the stack 22c. .

FIG. 2 is a block diagram schematically showing a microprocessor to which a program context control method according to another embodiment of the present invention is applied. This microprocessor is an Intel 80386/486 microprocessor, and an extended context save/restore means corresponding to the extended register save/restore function 15 in FIG. Mixed detection/extended register save/restore program 125
This is realized by

The CPU 101 has a 16-bit register group 1.
11 and an extended register group 112 expanded for 32 bits.
It has a subset register save/restore function 1 as a function to store register values when switching contexts.
13 and superset register save/restore function 114
and has.

On the memory 102, a subset OS 121 for a 16-bit program 122a, a task 122 running on the subset OS 121, and 3
It is assumed that there is a superset OS 123 that targets the 2-bit program 124a, and a task 124 that operates on the superset OS 123.

On the task 122, there is a 16-bit program 122a that uses the 16-bit register group 111;
1 to save register values of 16-bit register group 111
A 32-bit program 122 that uses a 6-bit TSS 122b, a stack 122c that stores register values of the extension register group 112, and a 32-bit register group (16-bit register group 111 and extension register group 112).
d exists.

On the task 124, there is a 32-bit program 124a that uses a 32-bit register group (16-bit register group 111 and extension register group 112);
3 to save register values of 32-bit register group (16-bit register group 111 and extension register group 112)
There is a 2-bit TSS 124b and a stack 124c.

In the program context control method of this embodiment configured as described above, the superset OS 12
The mixture detection/extended register save/restore program 125 included in 3 is called when switching tasks on the subset OS 121 or when accepting all external interrupts, and detects the difference between the context at that point and the register set of the program. However, it operates in the same manner as the extended register save/restore function 15 in FIG. Therefore, since the operation of the program context control method of this embodiment is almost the same as the operation of the program context control method of the embodiment shown in FIG. 1, a detailed explanation thereof will be omitted.

[0024]

As described above, the present invention detects the execution of a superset program on a context on the subset side when switching contexts, and stores extended registers that are not saved or restored by the subset context saving/restoring means. By making it possible to save and restore even values, subset OS and superset programs can be freely used together, and multiple subset OSes and superset OSes can be operated in parallel. have

[Brief explanation of the drawing]

FIG. 1 is a block diagram schematically showing a microprocessor to which a program context control method according to an embodiment of the present invention is applied.

FIG. 2 is a block diagram schematically showing a microprocessor to which a program context control method according to another embodiment of the present invention is applied.

[Explanation of symbols]

1,101 CPU 2,102 Memory 11 Subset register group 12 Extension register group 13, 113 Subset register save/restore function 14, 114 Superset register save/restore function 15 Extended register save/restore function 21, 121 Subset OS 22,122 Task 22a on the subset OS
Subset program 22b Context storage area 22c, 122c Stack 22d Superset program 23, 123 Superset OS 24, 124 Task 24a on superset OS
Superset program 24b Context storage area 24c, 124c Stack 111 16-bit register group 112 Extension register group 122a 16-bit program 122b 16-bit TSS 122d 32-bit program 124a 32-bit program 124b 32-bit TSS

Claims (1)

[Claims] 1. A microprocessor that simultaneously provides an execution environment for programs with two register sets, one as a subset and the other as a superset, and enables mixed operation, wherein register values for the subset are stored and stored in correspondence with the subset. A context saving/restoring means for the subset to be restored, a superset context saving/restoring means for saving and restoring register values for the superset corresponding to the superset, and a superset program executed on the context on the subset side. 1. A program context control method, comprising: an extended context saving/restoring means for detecting a case where the subset context saving/restoring means saves and restores an extended register value separately from the subset context saving/restoring means.