US 2014/0372651 A1Published application

Information processing apparatus, information processing method, and computer program product

AssigneeKabushiki Kaisha Toshiba

InventorsJun KANAI, Hiroshi Isozaki

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Abstract

According to an embodiment, an information processing apparatus includes a banked register determiner and a saving register determiner. The banked register determiner is configured to hold register information indicating which of a banked register and a non-banked register a register which is used by the operating system is, receive an acquisition instruction for the non-banked or banked register and the information about the mode of the operating system, and return a list of the non-banked or banked registers. The saving register determiner is configured to acquire the mode in which the operating system is capable of operating, determine that saving of the banked register for the mode is necessary when another operating system is capable of operating in the mode, acquire a list of the banked registers, and acquire a list of the non-banked registers from the banked register determiner.

Claims18

Dependent claims

An information processing apparatus where a plurality of operating systems are capable of operating in a plurality of modes, a register which is used by each operating system including a banked register whose area is allocated to each mode and a non-banked register shared by the modes, the apparatus comprising:

an instruction detector configured to issue a first request for switching the operating systems when detecting a switching instruction regarding the operating systems;
a switcher configured to issue a second request for saving and restoring the register when the switching instruction is detected, the second request specifying the operating system that is a switching source and the operating system that is a switching destination that are included in the first request;
a save information manager configured to hold information about the mode in which the operating system is capable of operating, and information about the banked register and the non-banked register that are saved at a time of switching, among the registers used by the operating system;
a banked register determiner configured to
hold register information indicating which of the banked register and the non-banked register the register is,
receive an acquisition instruction for the non-banked register or the banked register and the information about the mode, and
return a list of the non-banked registers or a list of the banked registers used in the received mode;
a saving register determiner configured to
acquire the mode in which the operating system that is the switching source is capable of operating from the save information manager,
determine that saving of the banked register for the mode is necessary when the operating system that is the switching source is capable of operating in the acquired mode, and when another operating system is capable of operating in the mode,
acquire a list of the banked registers that need to be saved by transferring the information about the mode to the banked register determiner, and
acquire a list of the non-banked registers from the banked register determiner;
and
a register saver/restorer configured to, in response to the second request,
acquire the lists of the banked registers that need to be saved and the non-banked registers from the saving register determiner,
acquire, from the save information manager, information about the register to be restored that was saved at a time of previous switching in the operating system that is the switching destination, and
save and restore the register.

14 more elements

An information processing method for an information processing apparatus where a plurality of operating systems are capable of operating in a plurality of modes, a register which is used by each operating system including a banked register whose area is allocated to each mode and a non-banked register shared by the modes, the method comprising:

issuing a first request for switching the operating systems when detecting an switching instruction regarding the operating systems;
issuing a second request for saving and restoring the register when the switching instruction is detected, the second request specifying the operating system that is a switching source and the operating system that is a switching destination that are included in the first request;
managing save information by holding information about the mode in which the operating system is capable of operating, and information about the banked register and the non-banked register that are saved at a time of switching, among the registers used by the operating system;
determining the register
by holding register information indicating which of the banked register and the non-banked register the register is,
by receiving an acquisition instruction for the non-banked register or the banked register and the information about the mode, and
by returning a list of the non-banked registers or a list of the banked registers used in the received mode;
determining a saving register
by acquiring the mode in which the operating system that is the switching source is capable of operating,
by determining that saving of the banked register for the mode is necessary when the operating system that is the switching source is capable of operating in the acquired mode, and when another operating system is capable of operating in the mode,
by acquiring a list of the banked registers that need to be saved by transferring the information about the mode to a banked register determiner, and
by acquiring a list of the non-banked registers from the banked register determiner;
and
saving and restoring the register,
in response to the second request,
by acquiring the lists of the banked registers that need to be saved and the non-banked registers, and
by acquiring information about the register to be restored that was saved at a time of previous switching in the operating system that is the switching destination.

14 more elements

A computer program product comprising a computer-readable medium containing a program executed by a computer where a plurality of operating systems are capable of operating in a plurality of modes, a register which is used by each operating system including a banked register whose area is allocated to each mode and a non-banked register shared by the modes, the program causing the computer to execute:

issuing a first request for switching the operating systems when detecting an switching instruction regarding the operating systems;
issuing a second request for saving and restoring the register when the switching instruction is detected, the second request specifying the operating system that is a switching source and the operating system that is a switching destination that are included in the first request;
managing save information by holding information about the mode in which the operating system is capable of operating, and information about the banked register and the non-banked register that are saved at a time of switching, among the registers used by the operating system;
determining the register
by holding register information indicating which of the banked register and the non-banked register the register is,
by receiving an acquisition instruction for the non-banked register or the banked register and the information about the mode, and
by returning a list of the non-banked registers or a list of the banked registers used in the received mode;
determining a saving register
by acquiring the mode in which the operating system that is the switching source is capable of operating,
by determining that saving of the banked register for the mode is necessary when the operating system that is the switching source is capable of operating in the acquired mode, and when another operating system is capable of operating in the mode,
by acquiring a list of the banked registers that need to be saved by transferring the information about the mode to a banked register determiner, and
by acquiring a list of the non-banked registers from the banked register determiner;
and
saving and restoring the register,
in response to the second request,
by acquiring the lists of the banked registers that need to be saved and the non-banked registers, and
by acquiring information about the register to be restored that was saved at a time of previous switching in the operating system that is the switching destination.

14 more elements

Dependencies are inferred from the claim text.