Method of flash programming or reading a rom of a computer system independently of its operating system

Abstract

A computer system provides for flashing a non-volatile memory image to a non-volatile memory and reading data from a non-volatile memory independently of an operating system. An image buffer is allocated in a volatile memory of the computer system. If flashing a non-volatile memory image to the non-volatile memory is desired, the image buffer is loaded with a portion of the non-volatile memory image. BIOS interface code is then called to place an SMI event code into a memory and to generate a system management interrupt causing the computer system to enter a system management mode. SMI handler code examines the SMI event code and calls SMI service code. Next, the image buffer is located and the portion of the non-volatile memory in the image buffer is flashed to the non-volatile memory by the SMI service code. Locating the image buffer may include locating an image header defined within the volatile memory. The image header may include a password for providing access to the non-volatile memory. The steps of loading the image buffer, calling BIOS interface code, and flashing a portion of the non-volatile memory image to the non-volatile memory may be repeated until the entire non-volatile memory image is flashed to the non-volatile memory. Alternatively, if reading data from a non-volatile memory independently of an operating system is desired, a system management interrupt is generated to place the computer system in a system management mode, an SMI event code is placed in a memory, the SMI handler code processes the SMI event code and calls SMI service code, the image buffer is located by the SMI service code, and the SMI service code copies data from the non-volatile memory to the image buffer.