2.2.3. Target Operations

A set of operations is required to access a program using the target architecture described by struct gdbarch in order to implement the target side functionality. For any given architecture there may be multiple ways of connecting to the target, specified using the GDB target command. For example with the OpenRISC 1000 architecture, the connection may be directly to a JTAG interface connected through the host computer's parallel port, or through the OpenRISC 1000 Remote JTAG Protocol over TCP/IP.

These target operations are described in a struct target_ops. As with struct gdbarch this comprises a mixture of data and functions. The major functional groups are:

Functions to establish and close down a connection to the target.
Functions to access registers and memory on the target.
Functions to insert and remote breakpoints and watchpoints on the target.
Functions to start and stop programs running on the target.
A set of data describing the features of the target, and hence what operations can be applied. For example when examining a core dump, the data can be inspected, but the program cannot be executed.

As with struct gdbarch, defaults are provided for the struct target_ops values. In many cases these are sufficient, so need not be provided.