The RSP packet exchanges to implement the GDB target extended-remote command are shown as a sequence diagram in Figure 3.9.

Figure 3.9.  RSP packet exchanges for the GDB target remote command

The dialog is almost identical to that for standard remote debugging (see Section 3.2.1). The difference is the penultimate ! packet, notifying the target that this is an extended remote connection.

Through this exchange, the GDB client shows the following output:

(gdb) target extended-remote :51000
Remote debugging using :51000
0x00000100 in _start ()
(gdb)