Browse Prior Art Database

Method of Customizing Patches for Each Hardware Configuration

IP.com Disclosure Number: IPCOM000043597D
Original Publication Date: 1984-Sep-01
Included in the Prior Art Database: 2005-Feb-05
Document File: 2 page(s) / 43K

Publishing Venue

IBM

Related People

Bradley, DJ: AUTHOR [+3]

Abstract

When using a transfer vector table (TVT) such as is shown in U.S. Patent 4,374,417, it sometimes becomes necessary to include a customized patch for a particular hardware configuration. Where the microcode used to operate the machine is contained in a read-only memory (ROM) which is not easily changed, it is desirable to eliminate the requirement to customize the ROM for each particular hardware configuration. It is desirable rather to provide a method for applying only those patches which are required for a particular hardware configuration. The method for customizing the patches is required to support both the read-only hardware and the preloaded hardware as well as the in-place replacement and add-on replacement of read-only memory modules.

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Method of Customizing Patches for Each Hardware Configuration

When using a transfer vector table (TVT) such as is shown in U.S. Patent 4,374,417, it sometimes becomes necessary to include a customized patch for a particular hardware configuration. Where the microcode used to operate the machine is contained in a read-only memory (ROM) which is not easily changed, it is desirable to eliminate the requirement to customize the ROM for each particular hardware configuration. It is desirable rather to provide a method for applying only those patches which are required for a particular hardware configuration. The method for customizing the patches is required to support both the read-only hardware and the preloaded hardware as well as the in-place replacement and add-on replacement of read-only memory modules. Described herein is a method for programming support to package patches in a single file for distribution without the need to customize a file for each hardware configuration. A prerequisite number and transfer vector table ID are packaged with each patch. This prerequisite number represents the level of the module that requires a patch. Embedded in each page is a unique number which represents the level of each module on that page. The transfer vector table points to the page address with the latest version of each module. When there is a prerequisite number and page number match, the patch can be applied. The transfer vector table, which resides in the unpaged random-access memory (RAM), contains the page number, patch bit and offset to the page for each program module in the read-only memory. The TVT is built dynamically at power-on time from a table within each read-only memory module. This program updates the TVT entry for each module it replaces. It changes three fields i...