Use of extra firmware flash ROM space as a diagnostic drive

#The present invention relates generally to computer systems and methods, and more particularly, to a system and method that provides for the use of available firmware flash ROM space as a diagnostic drive.

#The assignee of the present invention develops firmware known as a basic input and output system, or BIOS that is employed in variously available computer systems. The BIOS is a firmware program that is typically stored in a nonvolatile random access memory (or flash memory). The BIOS brings up the computer system when it is turned on.

#On IA-64 computer systems, manufactured by Intel, for example, 16 MB of address space has been reserved for flash ROM storage of the firmware (BIOS). The firmware developed by the assignee of the present invention may be adapted to fit within about 4 MB of disk space, leaving about 12 MB free (if the OEM populates the chips).

#The various features and advantages of the present invention may be more readily understood with reference to the following detailed description taken in conjunction with the accompanying drawing, wherein like reference numerals designate like structural elements, and in which:

#FIG. 1 illustrates an exemplary computer system in which the present invention is employed;

#FIG. 2 illustrates details of the present invention; and

#Referring to the drawing figures, FIG. 1 illustrates an exemplary computer system 10 in which the present invention may be employed. The computer system 10 comprises a central processing unit (CPU) 11 which is coupled to a hard disk drive 12 and a nonvolatile random access memory (NVRAM) 14, also known as flash memory 14. A hard disk drive 12 is shown as part of the system 10, which is typically the case, although one is not necessarily required.

#The computer system 10 also comprises a basic input and output system (BIOS) 16, which is stored in the flash memory 14. As will be discussed below, the BIOS 16 is stored in a relatively small portion of the flash memory 14. The computer system 10 also comprises an Extensible Firmware Interface (EFI) 15 which is a ROM-based operating system that is stored in the flash memory 14 that provides disk operating system (DOS) functionality for the computer system 10. The Extensible Firmware Interface 15 is controlled by the BIOS 16 and executes before any other operating systems are loaded or disk access is allowed.

#The Extensible Firmware Interface 15 comprises a command shell, which is the outermost layer or user interface of this program, and which has a command processor interface. The command processor is a program that executes operating system commands. The command shell is that part of the command processor that accepts commands. After verifying that the commands are valid, the shell sends them to another part of the command processor to be executed.