Using protected/hidden region of a magnetic media under firmware control

Abstract

A method and firmware for accessing a protected area of a magnetic storage device via firmware control. During early system initialization, various firmware components are loaded and executed to initialize a computer system. These firmware components include a firmware driver for accessing magnetic storage devices connected to the computer system. The system firmware enables a protected area on a magnetic storage device's media to be accessed under firmware control. After firmware accesses, the protected area is closed from access by non-firmware entities (e.g., operating systems) by “hiding” the true size of the media such that those entities are unaware of this area of the media. Mechanisms are disclosed for providing firmware access to the protected area only during pre-boot, and for both pre-boot and run-time operations. The firmware-controlled media access scheme may be used to load firmware stored on magnetic media during pre-boot and to store system information in the protected area during pre-boot and/or run-time operations.

1 . A method for accessing computer system firmware, comprising:
 accessing, via a first portion of firmware, a protected area of media on which data are stored by a magnetic storage device, said data including a second portion of firmware;   loading the second portion of firmware for subsequent use by the computer system, and preventing an operating system to run on the computer system from accessing the protected area of the media.   
   
   
       2 . The method of  claim 1 , wherein the operating system is prevented from accessing the protected area of the media by hiding the protected area of the media from the operating system. 
   
   
       3 . The method of  claim 1 , wherein the protected area of the media comprises a portion of the media having an address range defined by respective lower and upper address limits, and wherein the protected area is accessed by performing operations including:
 setting a maximum accessible address for the media to correspond to the upper address limit;   accessing the second portion of firmware; and   resetting the maximum accessible address for the media to correspond to the lower address limit.   
   
   
       4 . The method of  claim 3 , wherein the upper limit correspond to the native size of the media, the method further comprising determining the native size of the media. 
   
   
       5 . The method of  claim 3 , further comprising freezing the maximum accessible address such that it may not be changed until the computer system is reset or restarted. 
   
   
       6 . The method of  claim 1 , wherein the magnetic storage device is controlled by a controller that is compliant with the ATAPI 5 or later standard, and the method is implemented via commands corresponding to the ATAPI 5 or later host protected area (HPA) feature command set. 
   
   
       7 . The method of  claim 1 , further comprising accessing the protected area of the media during operating system runtime in a manner that is transparent to the operating system. 
   
   
       8 . The method of  claim 1 , further comprising employing a security mechanism to prevent components that are not authorized to access the protected area from accessing the protected area. 
   
   
       9 . The method of  claim 1 , wherein the second portion of firmware is stored in a firmware volume corresponding to the Extensible Firmware Interface (EFI) standard. 
   
   
       10 . The method of  claim 1 , further comprising saving system information to the protected area of the media. 
   
   
       11 . The method of  claim 10 , wherein the system information comprises an image of the boot code for the operating system. 
   
   
       12 . The method of  claim 10 , wherein the system information comprises system state information. 
   
   
       13 . The method of  claim 10 , wherein the system information comprises operating system file system information. 
   
   
       14 . The method of  claim 10 , wherein the system information is saved during system run-time. 
   
   
       15 . A machine-readable media on which firmware is stored, which when executed on a computer system performs operations including:
 loading a firmware driver for accessing a magnetic storage device;   accessing, via the firmware driver, a protected area of media on which data are stored by the magnetic storage device, said data including extended firmware; and   loading the extended firmware into system memory to enable subsequent use of the extended firmware by the computer system.   
   
   
       16 . The machine-readable media of  claim 15 , wherein execution of the firmware further performs the operation of configuring an access scheme for the magnetic storage device such that the protected area of the media is hidden from an operating system to run on the computer system. 
   
   
       17 . The machine-readable media of  claim 15 , wherein the protected area of the media comprises a portion of the media having an address range defined by respective lower and upper address limits, and wherein execution of the firmware accesses the protected area by performing operations including:
 setting a maximum accessible address for the media to correspond to the upper address limit prior to accessing the protected area of the media; and   resetting the maximum accessible address for the media to correspond to the lower address limit after completing access of the protected area of the media.   
   
   
       18 . The machine-readable media of  claim 17 , wherein execution of the firmware further performs the operation of freezing the maximum accessible address such that it may not be changed until the computer system is reset or restarted. 
   
   
       19 . The machine-readable media of  claim 15 , wherein execution of the firmware further performs the operations of:
 opening up the protected area of the media for access during system run-time operation;   saving system information to the protected area; and   closing the protected area of the media from access.   
   
   
       20 . The machine-readable media of  claim 19 , wherein the protected area is accessed in a manner that is transparent to the operating system. 
   
   
       21 . The machine-readable media of  claim 19 , wherein the system information is saved in response to a system event and execution of the firmware performs the further operations of:
 detecting the system event;   switching execution of a computer system processor from an operating system controlled execution mode to an execution mode that is hidden from the operating system;   servicing the system event by opening the protected area, writing system information pertaining to the system event to the protected area, and closing access to the system area; and   returning the execution mode of the processor back to the operating system controlled execution mode.   
   
   
       22 . The machine-readable media of  claim 21 , wherein the system event is an operating system crash, and the system information comprises system state information at the time of the operating system crash. 
   
   
       23 . A method comprising:
 collecting current system configuration information during computer system pre-boot operations;   opening, via firmware control, a protected area of media corresponding to a magnetic storage device for access;   writing data corresponding to the current system configuration in the protected area of the media; and   closing the protected area of the media from access.   
   
   
       24 . The method of  claim 23 , wherein the current system configuration information pertains to a configuration of the computer system's firmware. 
   
   
       25 . The method of  claim 23 , wherein the current system configuration information pertains to a configuration of the computer system's hardware. 
   
   
       26 . The method of  claim 23 , further comprising:
 in response to a system reset or power on startup event, collecting new current system configuration information during current computer system pre-boot operations;   opening, via firmware control, the protected area of media corresponding to a magnetic storage device for access;   retrieving data stored in the protected area of the media corresponding to a prior system configuration;   comparing the current system configuration information with the prior system configuration information; and   determining if a change in the system configuration has occurred based on the comparison.   
   
   
       27 . The method of  claim 26 , wherein it is determined that no change to the system configuration has occurred, further comprising closing access to the protected area of the media. 
   
   
       28 . The method of  claim 26 , wherein it is determined that a change in the system configuration has occurred, further comprising notifying at least one of the system and/or a user that a system configuration change has occurred. 
   
   
       29 . The method of  claim 28 , further comprising determining, via input from one of the system or the user, whether the change is authorized, and if it is, updating the system configuration information in the protected area of the media to reflect the new current configuration of the computer system. 
   
   
       30 . The method of  claim 28 , further comprising determining, via input from one of the system or the user, whether the change is authorized, and if it is not, rolling back the system configuration to correspond to the configuration defined by the prior system configuration information.