Multiple operating system control method

• US 6,715,016 B1
• Filed: 06/01/2000
• Issued: 03/30/2004
• Est. Priority Date: 06/01/2000
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Ohno, Hiroshi, Yamauchi, Manabu, Arai, Toshiaki, Nakamura, Tomoaki, Sekiguchi, Tomoki, Kaneko, Shigenori, Kato, Naoshi, Yoshizawa, Ryokichi
• Primary Examiner(s): Myers, Paul R.
• Application Number:
  US09/585,120
• Time in Patent Office: 1,398 Days
• Field of Search: 710/260, 709/108
• US Class Current: 710/260
• CPC Class Codes: G06F 9/45533 Hypervisors; Virtual machine monitors
• CPC Class Codes: G06F 9/4812 by interrupt, e.g. masked
• CPC Class Codes: G06F 9/4843 by program, e.g. task dispatcher, supervisor, operating system

Abstract

An inter-OS control software for switching OS'"'"'s in operation executed on a single CPU is installed, and plural OS'"'"'s are made alternately executed. A control program is executed exclusively on one OS, which controls the controlled apparatus. A supervisory control program and a development environment program are executed on another OS, and a memory space is divided so as to make no effect for the operation of the control program. A higher real-time performance and reliability can be established with a single CPU architecture.

Claims

1. A multiple operating system control method for a multiple operating system having plural operating systems executed in a digital arithmetic processor and including a first operating system and a second operating system and a plurality of pieces of hardware, each piece of hardware assigned to a corresponding operating system, comprising:

assigning interrupt numbers to respective pieces of hardware and storing them in a table so as to maintain the operating systems independent from each other;

alternately switching, under inter-operating system control software control, on the basis of said table, between and said first and second operating systems to alternately execute said first and second operating systems; and

reserving an interrupt number or an input and output address used by said second operating system for said first operating system when starting said first operating system.

2. A multiple operating system control method of claim 1,

wherein a conversion table used by said digital arithmetic processor for converting a virtual memory address to a physical address is defined in each of said first and second operating systems; and

when executing a switching procedure for selecting one of said first and second operating systems, which is called as a interrupt processing routine or called by said first and second operating systems individually when an interrupt occurs, a procedure for directing said digital arithmetic processor to use the conversion table for an operating system to be executed after switching is executed when selecting and switching an operating system.

3. An multiple operating system control method of claim 1, and further comprising:

a. assigning a priority level to each individual operating system of said plural operating systems during operation;

b. preferentially executing a program on a high priority operating system by;

i. not switching the high priority operating system to an operating system with a lower priority level, or

ii. switching the high priority operating system to an operating system lower in priority for a definite time interval and then switching back to the operating system with a high priority.

4. A multiple operating system control method according to claim 1, wherein the interrupt table is divided into two so as to separately use them for the operating systems, the interrupt table being switched from one of the two to the other thereof when an interrupt occurs.

5. A multiple operating system control method according to claim 1, wherein I/O addresses assigned respectively to the pieces of hardware are stored in the table so as to maintain the operating systems independent of each other.

6. A multiple operating system control method according to claim 5, wherein the inter-operating system control software accepts an interrupt from an interrupt controller and an interrupt from a timer.

7. A multiple operating system control method according to claim 6, wherein the inter-operating system control software causes one of the operating systems to be assigned more preferentially than the other thereof.

8. A multiple operating system control method according to claim 7, wherein the other of the operating systems is operated as a device driver.

9. A multiple operating system control method according to claim 8, wherein the operating systems and the inter-operating system control software are operated in a privileged mode, but a program is not.