Lenovo (singapore) Pte. Ltd.

Norihito Ishida

Toyoaki Inada

Seiichi Kawano

Noritoshi Yoshiyama

Eitaroh Kasamatsu

Yasumasa Takeda

A method for protecting a privilege level of a system management mode (SMM) of a computer system is disclosed. A SMM program is loaded into a special memory (SMRAM) area within a system memory of a computer. A first program, a second program, and a vector table are loaded into a general area of the system memory. Before the booting process of the computer has been completed, a reference hash value of the first program is determined by the SMM program, and the reference hash value is stored in the SMRAM area. A hash value of the first program is the computed by the SMM program. After the computer has been operating under an operating environment of an operating system, the computed hash value is compared to the reference hash value. When the computed hash value matches the reference hash value, the first program is called by the SMM program.

Method for protecting a privilege level of system management mode of a computer system

An information processor includes a power-saver which switches a display memory to a power-saving state that causes image data to be lost and restores the display memory from the power-saving state. A storage area stores a predetermined activation condition and an activation routine mechanism activates a predetermined routine when the activation condition is satisfied. A routine termination mechanism ends the routine and an image data re-creation mechanism executes re-creation of the image data on the display memory when the routine is terminated. Provided are: an activation condition rewriting mechanism which rewrites the activation condition stored in the storage area so that the routine is activated when the display memory is switched to or restored from the power-saving state; and an activation condition restoration mechanism which restores the rewritten activation condition to the original condition after the routine is activated.

Growing community of inventors

Yokohama, Japan

Norihito Ishida