ARM DS-5 Using the Debug Hardware Configuration Utilities

Configuring debug hardware for GDB9.11 Connections to a target GDB stub using Virtual Ethernet/TTY mode(Target-GDB-Virtual Ethernet)If your target application requires TCP/IP communication with the debug host, you can connectto the target using Virtual Ethernet/TTY mode. Connections of this type are referred to asTarget-GDB-Virtual Ethernet connections. This method is an extension to that used forconnections to a target running an application with a GDB stub. The following figure shows anexample:Debug hostDebug unitConfigurationMechanismSet up JTAGscan chainTargetGDBBridged Ethernet(IP)VirtualEthernetDCC(IP over DCC)ApplicationGDB stubFigure 9-3 Target-GDB-Virtual Ethernet connectionsIn this method, debug hardware provides a network bridging feature to targets, and enables atarget with only a JTAG connection to debug hardware to have access to the same networkresources available to debug hardware. This works by intercepting IP packets on the networkand examining them, and those packets that are addressed to the target are then sent over DCCalongside the normal GDB protocol. A driver is required on the target to interface the DCCchannel to the protocol stack of the target, making the bridged network connection appear as anEthernet device on the target. IP is the only network layer protocol supported.NoteTo reduce the load on the DCC and JTAG connection, broadcast packets are not sent to thetarget.9.11.1 Target-GDB-Virtual Ethernet ScenarioUse the Target-GDB-Virtual Ethernet connection method to communicate with a standaloneapplication that has a TCP/IP stack. For example, an application might provide a web server thatserves web pages to the host.9.11.2 ProcedureTo use the Target-GDB-Virtual Ethernet connection method:• It is recommended that you compile the DCC driver and GDB stub into your targetapplication using a GNU toolchain for ARM ® architectures. The DCC driver is availableas a Linux OS download from the ARM products and solutions website.NoteOn the GDB connection to the target, you must enable DCC and Virtual Ethernet/TTYmode before starting the processor.• The target application must be running a TCP/IP stack.ARM DUI 0498F Copyright © 2010-2012 ARM. All rights reserved. 9-15ID021112Non-Confidential