Information processing device and activation control method

The present invention relates to an information processing device such as a personal computer, and particularly to an information processing device the system of which can be safely activated by an external device, and also to an activation control method adopted in such a device.

In a personal computer in general, when its chipset is not started, a wakeup event cannot be issued from a device that utilizes a USB Wakeup function or the like. For this reason, Jpn. Pat. Appln. KOKAI Publication No. <patcit id="pcit0001" dnum="JP8063252A"><text>8-63252</text></patcit> discloses a technology of delivering a wakeup event from the device to a power management module (hereinafter, referred to as "PMM") by bypassing the chipset, with a sideband signal line through which only a pull-up signal can be sent between the device and the PMM.

With this technology, the system may be started up even when the chipset is not activated. However, because of the simple structure of the wakeup signal, the system may be illegally started with a faked signal, creating a security problem.

The present invention has been conceived in light of the above problem. The purpose of the invention is to offer an information processing device and an activation controlling method that both can verify a wakeup signal before activating the system.

In order to achieve the above purpose, an information processing device according to an embodiment of the present invention, which activates the system with a trigger signal sent from a device connected thereto, comprises a receiving section configured to receive the trigger signal from the connected device, and a verifying section configured to verify the trigger signal when the receiving section receives the trigger signal. When verification of the trigger signal is successfully made by the verifying section, the system is activated.

The present invention also offers an activation control method for activating a system with a trigger signal issued by a device connected thereto. The method comprises a receiving step in which the trigger signal is received from the connected device, and a verifying step in which the trigger signal is verified when the trigger signal is received in the receiving step. When verification of the trigger signal is successfully made in the verifying step, the system is activated.

According to the present invention, security of the system can be improved by verifying a wakeup event before the activation of the system.

The invention can be more fully understood from the following detailed description when taken in conjunction with the accompanying drawings, in which: <ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">FIG. 1</figref> is a perspective overview of a computer according to an embodiment of the present invention.</li><li><figref idref="f0002">FIG. 2</figref> is a block diagram of the system of the computer according to the embodiment of the present invention.</li><li><figref idref="f0003">FIG. 3</figref> is a block diagram of the functional structure of the computer according to the embodiment of the present invention.</li><li><figref idref="f0003">FIG. 4</figref> is a flowchart of an activation control method for a computer according to an embodiment of the present invention.</li><li><figref idref="f0004">FIG. 5</figref> is a flowchart of a modified example of the activation control method for a computer according to an embodiment of the present invention.</li></ul>

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

The structure of an information processing device according to an embodiment of the present invention will be first discussed with reference to <figref idref="f0001">FIGS. 1</figref> and <figref idref="f0002">2</figref>. The information processing device is realized here in the form of a notebook personal computer 10.

<figref idref="f0001">FIG. 1</figref> shows a perspective view of the notebook personal computer 10 with its display unit open. The computer 10 comprises a computer main unit 11 and a display unit 12. A display device formed of a thin film transistor liquid crystal display (TFT-LCD) 17 is incorporated in the display unit 12, and the display screen of the LCD 17 is positioned substantially in the center of the display unit 12.

The display unit 12 is arranged on the computer main unit 11 rotatably between an open position and a close position. The computer main body 11 is a thin box housing, on top of which a keyboard 13, a power switch 14 for turning on/off the computer 10, an input operation panel 15, a touch pad 16, and a pair of speakers 18A and 18B.

The input operation panel 15 is an input device for inputting an event in correspondence with a pressed button, and has different buttons to activate different functions.

In addition, a device 400 is connected to the computer 10 by way of a USB cable 402, which is connected to a later-described USB host controller 403. This device 400 conforms to the USB standards.

Next, the structure of the system of the computer 10 will be explained with reference to <figref idref="f0002">FIG. 2</figref>.

As illustrated in <figref idref="f0002">FIG. 2</figref>, the computer 10 comprises a CPU 111, a north bridge 112, a main memory 113, a south bridge 115, a graphics controller 114, BIOS-ROM 118, a network controller 117, a hard disk drive (HDD) 116, an embedded controller/keyboard controller (EC/KBC) 119, a power supply circuit 120, and the like.

The CPU 111 is a processor that controls the operation of the computer 10 and executes the operating system and various applications loaded from the HDD 116 into the main memory 113. The CPU 111 also executes the Basic Input/Output System (BIOS) stored in the BIOS-ROM 118. The BIOS is a hardware controlling program.

The north bridge 112 is a bridge device bridging the local bus of the CPU 111 and the south bridge 115. The north bridge 112 includes a memory controller that controls the access to the main memory 113. The north bridge 112 also conducts communications with the graphics controller 114 by way of a PCI Express serial bus or the like.

The graphics controller 114 is a display controller that controls the LCD 17 employed as a display monitor of the computer 10. A display signal generated by the graphics controller 114 is sent to the LCD 17.

The south bridge 115 controls devices on the low pin count (LPC) bus and on the peripheral component interconnect (PCI) bus. The south bridge 115 includes an integrated drive electronics (IDE) controller to control the HDD 116.

The embedded controller/keyboard controller (EC/KBC) 119 is a one-chip microcomputer in which an embedded controller for managing power supply and a keyboard controller for controlling the keyboard (KB) 13 and the touch pad 16 are integrated. The EC/KBC 119 turns the computer 10 on/off in accordance with the user's operation of the power switch 14.

The device 400 is connected to the computer 10 by way of the USB cable 402 via the USB host controller 403 that is connected on the PCI bus. The device 400 is also connected to a sideband 401, which is a line specially designed to transmit a pull-up signal (trigger signal) to the EC/KBC 119.

Next, <figref idref="f0003">FIG. 3</figref> is a block diagram of the functional structure of the information processing device according to the embodiment of the present invention.

A controlling section 20, a memory section 21, a verifying section 22, and a receiving section 23 are included as functional sections in the embodiment of the information processing device according to the present invention. The controlling section 20 is the CPU 111, which controls the entire system. The memory section 21 is a flash memory that stores verification information and encryption information (such as encryption keys). The information may be stored in the BIOS-ROM 118. The verifying section 22 is the BIOS-ROM 118, which verifies the trigger signals and devices. The receiving section 23 is the EC/KBC 119 and the USB host controller 403 that exchange signals with the device 400.

An activation control method to which the information processing device according to the embodiment of the present invention is applied will now be explained with reference to the flowchart of <figref idref="f0003">FIG. 4</figref>.

The EC/KBC 119 monitors reception of a pull-up signal, which is a trigger signal from the device 400 (step S101). When a pull-up signal that is a trigger signal is received from the device 400 (Yes in step S101), the EC/KBC 119 starts preparing the activation of the system (personal computer 10) (step S102). In accordance with the preparation of the system activation by the EC/KBC 119, the chipset is activated (step S103). Thereafter, the BIOS is activated (step S104).

The BIOS (verifying section) checks with the device 400 by way of the chipset to determine whether the pull-up signal that is a trigger signal has been transmitted (signal verification) (step S105). When the BIOS confirms with the device 400 in step S105 that the pull-up signal that is a trigger signal has been transmitted (signal verification successfully made, Yes in step S105), the system is activated (step S106). On the other hand, when the BIOS cannot confirm with the device 400 that the pull-up signal that is a trigger signal has been transmitted (failure of signal verification, No in step S105), the signal is considered as being illegally fabricated. Thus, the system is shut down (step S107). Instead of shutting down, the system may be put into a sleep mode, a suspend mode, or a lock mode. Furthermore, when exchanging signals during the verification, the signals may be encrypted.

A pull-up signal received from a USB-connected device is verified as discussed above, and thus the system can be prevented from being activated by an illegal pull-up signal, and security can be improved.

Next, a modification example will be explained with reference to the flowchart of <figref idref="f0004">FIG. 5</figref>.

Steps S201 through S205 in <figref idref="f0004">FIG. 5</figref> are the same as steps S101 through S105 in <figref idref="f0003">FIG. 4</figref>. In step S205, device verification is conducted for the device 400. When the verification is successfully made (Yes in step S205), the BIOS checks with the device 400 to determine whether the pull-up signal that is a trigger signal has been transmitted (signal verification) (step S206). When the signal verification is successfully made (Yes in step S206), the system is activated (step S207). On the other hand, when the device verification made for the device 400 by the BIOS is not successful in step S205 (No in step S205), the device is considered illegal, and the system is shut down (step S208). Further, when the signal verification made by the BIOS is not successful in step S206 (No in step S206), the device is considered illegal, and the system is shut down (step S208). Instead of shutting down, the system may be put into a sleep mode, a suspend mode, or a lock mode. Furthermore, when exchanging signals during the signal verification, the signals may be encrypted. When exchanging signals during the device verification for the device 400, the signals may also be encrypted.

With the above modification example, security can be further improved than with the technology according to the aforementioned embodiment.

The present invention is not limited to the above embodiment and modification example, but can be realized, when it is implemented, by modifying the structural components within the scope of the invention. In addition, various combinations of the structural components disclosed above can provide various inventions. For instance, some of the structural components may be omitted from the embodiment or the modification example, or the structural components in the embodiment and the modification example may be suitably combined.