Method of updating firmware without affecting initialization information

• US 6,237,091 B1
• Filed: 10/29/1998
• Issued: 05/22/2001
• Est. Priority Date: 10/29/1998
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: OʼBrien, Michael, Firooz, Jonathan
• Primary Examiner(s): Lee, Thomas
• Assistant Examiner(s): Mai, Rijue
• Application Number:
  US09/182,350
• Time in Patent Office: 936 Days
• Field of Search: 713/1, 713/2, 713/100, 709/220, 709/221, 709/222, 709/305, 717/11, 710/8, 710/10
• US Class Current: 713/1
• CPC Class Codes: G06F 8/65 Updates security arrangements therefor G06F21/57

Abstract

A firmware controlled device saves status and configuration information in a separate portion of memory that is not affected by a firmware update. In addition, information that may change during a firmware update, and may need to remain constant, is saved in the separate portion of memory that is not affected by a firmware update. In a first example embodiment, a reset process for the firmware controlled device is divided into two portions. In a first portion of the device reset process, the contents of the separate portion of memory are updated, either from firmware or by interaction with other devices. In a second portion of the device reset process, all other reset functions are performed. The first portion of the reset process is performed only during a power-on reset, or in response to an overall system reset. In particular, the first portion of the device reset process is not performed after a firmware update. In the second example embodiment, data that needs to remain constant are copied to the separate portion of memory as part of a firmware update process. Then, as part of a reset process, the device checks to see if a firmware update has occurred. If a firmware update has occurred, the data in the separate portion of memory are copied to the appropriate destinations, and the data in the separate portion of memory are cleared. As a result, for either example embodiment, the contents of the separate portion of memory are not disturbed during or after a firmware update, and a system reboot is not necessary after a device firmware update.

Claims

1. A method of changing firmware, the method comprising:

performing a configuration operation, by the firmware, when a hard reset is detected;

performing a soft reset operation, after the configuration operation, in which information from the configuration operation is used;

saving information obtained in the configuration operation, in a portion of memory that will not be changed during a firmware update, and then updating the firmware, when a need for a firmware update is detected;

performing the soft reset operation, by the updated firmware, using the saved information, without performing the configuration operation.

2. A method of changing firmware, the method comprising:

performing an initialization operation, by the firmware;

obtaining initialization information, by the firmware, during the initialization operation;

saving the initialization information in a portion of memory that will not be changed during a firmware update;

updating the firmware; and

performing an initialization operation, by the updated firmware, using the initialization information that has been saved instead of obtaining new initialization information.