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Method for integrated flexible escape-sequence filtering for a management microcontroller

IP.com Disclosure Number: IPCOM000009601D
Publication Date: 2002-Sep-04
Document File: 3 page(s) / 86K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for integrated flexible escape-sequence filtering for a management microcontroller. Benefits include improved performance and improved design flexibility.

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Method for integrated flexible escape-sequence filtering for a management microcontroller

Disclosed is a method for integrated flexible escape-sequence filtering for a management microcontroller. Benefits include improved performance and improved design flexibility.

Background

              Conventional solutions use external components or management microcontroller firmware to do the filtering. Using integrated filtering reduces the system component count and cost.

              Server system management typically includes a management microcontroller that autonomously monitors the system’s health. These microcontrollers are typically directly accessible via communication paths such as LAN and serial connections. A remote console application uses that path to communicate with the management microcontroller. Similarly, system firmware (such as BIOS and the operating system) and other software (such as operating system loader and install software) can often be managed using a serial connection to the system’s serial controller.

              To reduce connections to the system, the serial connection is typically shared with the management microcontroller. To accomplish this sharing, a mechanism is required to control the use of the connection by the management microcontroller or by the system’s serial controller. The solution is, typically, to embed special character sequences (escape sequences) in the serial stream. Standards have defined escape sequences/patterns for serial switching.

              The escape sequences are detected/intercepted in the serial stream that is coming in to the managed system. Detection is accomplished using escape sequence filters. There are two types of filters, fixed and configurable. Fixed filters are hardcoded to filter a particular data pattern. Configurable filters are management-microcontroller firmware to filter various data patterns.

Description

              The disclosed method is integrated hardware for detecting escape sequences for switching a serial connection between a management microcontroller and an embedded serial controller (see Figures 1 and 2). The implementation assumes a management microcontroller with a built-in 16550 serial controller.

              The disclosed method includes pattern-age expiration timers that can automatically retire a match-in-progress if it does not complete within a configurable interval of time.

Advantages

             

Some implementations of the disclosed structure and method provide one or more of the following advantages...