8.2.1. Summary of the connection methods for each debugging mode

How you connect to a target determines the debugging mode. The following sections describe the connection methods for each debugging mode.

Halt-mode debugging

Halt-mode debugging is the simplest method of debugging a target with GDB. You directly connect to RealView ICE, that then controls the starting and stopping of the processor. This method of connecting is subsequently referred to as an RVI-GDB connection.

See Connections to a target without built-in GDB support (RVI-GDB) for more details.

Monitor-mode debugging

Monitor-mode debugging requires that your target application communicate with GDB using the Debug Communications Channel (DCC) of an ARM architecture-based processor. However, if your target application includes an Ethernet facility, you do not have to use DCC. Different DCC modes are available depending on the requirements of your target (see DCC modes for more details).

The connection methods for Monitor-mode debugging are:

Target-GDB connections

Semi-transparent connections to GDB stubs. The GDB stubs run on individual CPU targets and communicate through the DCC of the target. The GDB stub must be compiled into the target application. See Connections to a target with a GDB stub (Target-GDB) for more details.

Target-GDB-Virtual Ethernet connections

An extension to Target-GDB connections for standalone applications running an IP stack. The TCP/IP connections are bridged by the RealView ICE unit from the target through DCC to the Ethernet port of the RealView ICE unit. See Connections to a target GDB stub using Virtual Ethernet/TTY mode (Target-GDB-Virtual Ethernet) for more details.

GDBserver connections

An alternative to Target-GDB-Virtual Ethernet connections where the target is running gdbserver running under an operating system (OS). See Connections to a target OS using gdbserver (GDBserver) for more details.

GDB-NFS connections

Connections to the root filesystem on the target OS that is mounted over NFS. The RealView ICE unit acts as a bridge between the debug host and the target OS. See Connections to a target OS using NFS (GDB-NFS) for more details.

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