Computer systems with several operating systems coexisting thereon and swapping between these operating systems

• US 7,409,536 B2
• Filed: 02/18/2005
• Issued: 08/05/2008
• Est. Priority Date: 02/18/2004
• Status: Active Grant

• Current Assignee: Lenovo PC International Limited (Lenovo Group Ltd.)
• Original Assignee: International Business Machines Corporation
• Inventors: Su, Hui, Guo, Xiao Bing, Wang, Zhe Peng, Wang, Tian Shu
• Primary Examiner(s): Patel; Nitin C
• Application Number:
  US11/061,396
• Publication Number:
  US 20050182922A1
• Time in Patent Office: 1,264 Days
• Field of Search: 713/1, 713/2, 713/100, 719311-332, 718 1-108
• US Class Current: 713/1
• CPC Class Codes: G06F 9/441 Multiboot arrangements, i.e. selecting an operating system to be loaded
• CPC Class Codes: G06F 9/4843 by program, e.g. task dispatcher, supervisor, operating system

Abstract

Computer systems in which at least two operating systems coexist independently from each other, and that swap between the operating systems. Provides methods to have at least two operating systems coexist independently of each other and swap the operating systems. A computer system includes a memory allocation component to be called by a power-on self test (POST) routine in order to allocate RAM for the operating systems when the computer system starts up, and backup and restore component to be called by a suspension routine in order to backup and restore the data specific to the operating systems, wherein each of the operating systems can transfer itself to the memory area belonging to itself, turn an allocated memory area into a physical RAM, and call the suspension routine to swap to other operating systems by setting swap parameters. The computer system can swap between operating systems easily and conveniently.

Claims

1. A computer system comprising:

at least two operating systems coexisting independently of each other, said computer system further comprising a random access memory and a basic input output system (BIOS) stored in read-only memory, with the BIOS including a power-on self test routine to invoke a first operating system from said at least two operating systems to be an invoked operating system when said first operating system is without a fault, and to invoke another operating system from said at least two operating systems to be the invoked operating system when said first operating system is with the fault, and each of the operating systems including a boot loader routine and a suspension routine;

an operating system swap core in the BIOS that includes a memory allocation component invoked by the power-on self test routine upon the computer system startup to allocate a random access memory area for each of the operating systems, and a backup and restore component invoked by the suspension routine to backup and restore data specific to each of the operating systems,

wherein each of the operating systems further includes a boot loader patch routine to transfer each corresponding operating system to memory area allocated by the operating system swap core and set allocated memory area as a physical memory available for the corresponding operating system; and

each of the operating systems further comprising a swap routine to set swap parameters and invoke a suspension routine in the corresponding operating system to give system control to the operating system swap core, such that said computer system is enabled to swap between the operating systems when said invoked operating system is subject to a virus attack or crash due to one of;

a fault, a deletion of files, and formatting of logical disk drives.

2. A computer system as claimed in claim 1, wherein the computer system is an i386-based architecture with Advanced Configuration and Power Interface.

3. A computer system as claimed in claim 1, wherein the computer system has two operating systems coexisting in the random access memory.

4. A computer system as claimed in claim 1, wherein the operating systems are of a same type of operating system.

5. A computer system as claimed in claim 1, wherein the memory allocation component allocates in the random access memory the same number of operating system memory areas as that of the operating systems and the same number of operating system-specific data backup areas as that of the operating systems, with the operating system memory areas acting as a random access memory for the operating systems and the operating system-specific data backup areas acting to store current setting information of a respective operating system for the computer system.

6. A computer system as claimed in claim 5, wherein the backup and restore component further includes a suspension swap routine for loading Master Boot Record by the operating system swap core and for jumping to Master Boot Record during the initial operating system swap, while during a non-initial operating system swap, the operating system swap core backups the setting information of a current operating system for the computer system into the corresponding operating system-specific backup area, then restores the setting of another operating system for the computer system and wakes up the another operating system, and then jumps to the waken-up operating system.

7. A computer system as claimed in claim 5, wherein the memory allocation component allocates in the highest memory area a first operating system memory area as the random access memory for a first operating system, and allocates in a low memory area a second operating system memory area as the random access memory for a second operating system.

8. A computer system as claimed in claim 7, wherein the boot loader patch routine of the first operating system comprises at least one of loading and moving the first operating system into the first operating system memory area allocated by the memory allocation component, setting a used indicator for the second operating system memory area to ensure that the second operating system memory area will neither be written into by the first operating system nor transferred by the first operating system to a swap partition on disk, indicating the second operating system memory area as a memory area read only by some system management applications, and registering to the first operating system a swap routine that implements swap service.

9. A computer system as claimed in claim 8, wherein the swap routine of the first operating system is used to invoke the suspension routine in the first operating system after the swap parameters are set.

10. A computer system as claimed in claim 9, wherein the boot loader patch routine of the second operating system is configured to transfer the second operating system into the second operating system memory area allocated by the operating system swap core, and register to the second operating system a swap routine that implements swap service.

11. A computer system as claimed in claim 10, wherein the swap routine of the second operating system is configured to invoke the suspension routine in the second operating system after the swap parameters are set.

25. A computer program product comprising a computer usable medium having computer readable program code means embodied therein for causing functions of a computer system, the computer readable program code means in said computer program product comprising computer readable program code means for causing a computer to effect the functions of claim 1.

12. A method comprising:

hosting at least two operating systems independently from each other on a computer system and enabling swapping between the operating systems, with the computer system including a random access memory and a BIOS stored in a read-only memory and the BIOS including a the power-on self test routine, and each of the operating systems including a boot loader routine and a suspension routine, the step of hosting comprising the following steps;

1) providing an operating system swap core in the BIOS to allocate a RAM area for each of the operating systems upon the computer system startup and to be invoked by the suspension routine to backup and restore data specific to each of the operating systems;

2) upon the power-on self test, using the operating system swap core to allocate in the random access memory for each of the operating systems a respective operating system memory area as a random access memory for the operating system;

3) after the power-on self test, using the operating system swap core to backup an original setting information of the computer system;

4) according to the original setting information, starting up a first operating system, which will transfer itself into the operating system memory area allocated to the first operating system;

5) using the operating system swap core to backup the current setting of the computer system, and then restoring the original setting information of the computer system, without the power-on self test and according to the original information starting up a second operating system, which will transfer itself into the operating system memory area allocated to the second operating system;

6) repeating step

     4) to startup the remaining operating systems until all the operating systems have been sequentially started up; and

7) providing in the current operating system a swap routine to invoke the suspension routine to give control of the computer system to the operating system swap core in order to backup the current operating system preparing to suspension and restore the setting information for the computer system of another operating system ready to wake up, thus waking up the another operating system.

13. The method as claimed in claim 12, wherein the computer system is an i386-based architecture with ACPI.

14. The method as claimed in claim 12, wherein the step 2) further includes using the operating system swap core to allocate upon the power-on self test in the random access memory for each of the operating systems a respective operating system-specific data backup area to keep the current setting information for the computer system of respective operating system.

15. The method as claimed in claim 14, wherein the step 3) further includes keeping the original setting information for the computer system in a second operating system-specific data backup area.

16. The method as claimed in claim 15, wherein steps 4) and 6) both include invoking after the starting up the swap routine of the operating system to give control of the computer system to the operating system swap core.

17. The method as claimed in claim 12, wherein the computer system has two operating systems coexisting in the random access memory.

18. The method as claimed in claim 12, wherein the operating systems are of the same type of operating system.

19. The method as claimed in claim 12, wherein the step 7) further includes using the operating system swap core during the initial operating system swap to load and jump to the Master Boot Record and using the operating system swap core during a non-initial operating system swap to backup the setting information of current operating system for the computer system into the corresponding operating system-specific backup area, then restore the setting of another operating system and wake up the another operating system, and then jump to the waken-up operating system.

20. The method as claimed in claim 12, wherein the memory area to keep the first operating system is in the highest memory area of the random access memory and the memory area to keep the second operating system is in a low memory area of the random access memory.

21. The method as claimed in claim 12, wherein the step 4) includes:

providing in the boot loader routine of the first operating system a boot loader patch routine;

using the boot loader patch routine to load and/or transfer the first operating system into the first operating system memory area;

using the boot loader patch routine to set a used indicator for the second operating system memory area to ensure that the second operating system memory area will neither be written into by the first operating system nor transferred by the first operating system to a swap partition on disk; and

using the boot loader patch routine to indicate the second operating system memory area as a memory area read only by some system management applications, and register to the first operating system a swap routine that implements swap service.

22. The method as claimed in claim 21, wherein the step 5) further includes:

providing in the boot loader routine of the second operating system a boot loader patch routine; and

using the boot loader patch routine to transfer the second operating system into the second operating system memory area allocated by the operating system swap core, and register to the second operating system a swap routine that implements swap service.

24. A program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform method steps for hosting at least two operating systems, said method steps comprising the steps of claim 12.

23. An article of manufacture comprising a computer usable medium having computer readable program code means embodied therein for causing hosting of at least two operating systems, the computer readable program code means in said article of manufacture comprising computer readable program code means for causing a computer to effect the steps of:

hosting at least two operating systems independently from each other on a computer system and enabling swapping between the operating systems, with the computer system including a random access memory and a BIOS stored in a read-only memory and the BIOS including a the power-on self test routine, and each of the operating systems including a boot loader routine and a suspension routine, the step of hosting comprising the following steps;

1) providing an operating system swap core in the BIOS to allocate a RAM area for each of the operating systems upon the computer system startup and to be invoked by the suspension routine to backup and restore the data specific to each of the operating systems;

2) upon the power-on self test, using the operating system swap core to allocate in the random access memory for each of the operating systems a respective operating system memory area as a random access memory for the operating system;

3) after the power-on self test, using the operating system swap core to backup the original setting information of the computer system;

4) according to the original setting information, starting up a first operating system, which will transfer itself into the operating system memory area allocated to the first operating system;

5) using the operating system swap core to backup the current setting of the computer system, and then restoring the original setting information of the computer system, without the power-on self test and according to the original information starting up a second operating system, which will transfer itself into the operating system memory area allocated to the second operating system;

6) repeating step

     4) to startup the remaining operating systems until all the operating systems have been sequentially started up; and

7) providing in the current operating system a swap routine to invoke the suspension routine to give control of the computer system to the operating system swap core in order to backup the current operating system preparing to suspension and restore the setting information for the computer system of another operating system ready to wake up, thus waking up the another operating system.