Use the special
GDB command `device port' if you
need to explicitly set the serial device. The default port is the
first available port on your host. This is only necessary on Unix
hosts, where it is typically something like `/dev/ttya'.
GDB has another special command to set the communications
speed: `speed bps'. This command also is only used from Unix
hosts; on DOS hosts, set the line speed as usual from outside GDB with
mode command (for instance,
mode com2:9600,n,8,1,p for a 9600bps connection).
The `device' and `speed' commands are available only when you
use a Unix host to debug your Hitachi microprocessor programs. If you
use a DOS host,
GDB depends on an auxiliary terminate-and-stay-resident program
asynctsr to communicate with the development board
through a PC serial port. You must also use the DOS
to set up the serial port on the DOS side.
The following sample session illustrates the steps needed to start a program under GDB control on an H8/300. The example uses a sample H8/300 program called `t.x'. The procedure is the same for the Hitachi SH and the H8/500.
First hook up your development board. In this example, we use a
board attached to serial port
COM2; if you use a different serial
port, substitute its name in the argument of the
When you call
asynctsr, the auxiliary comms program used by the
debugger, you give it just the numeric part of the serial port's name;
for example, `asyncstr 2' below runs
C:\H8300\TEST> asynctsr 2 C:\H8300\TEST> mode com2:9600,n,8,1,p Resident portion of MODE loaded COM2: 9600, n, 8, 1, p
Warning: We have noticed a bug in PC-NFS that conflicts with
asynctsr. If you also run PC-NFS on your DOS host, you may need to disable it, or even boot without it, to use
asynctsrto control your development board.
Now that serial communications are set up, and the development board is
connected, you can start up GDB. Call
the name of your program as the argument.
you, as usual, with the prompt `(gdb)'. Use two special
commands to begin your debugging session: `target hms' to specify
cross-debugging to the Hitachi board, and the
load command to
download your program to the board.
load displays the names of
the program's sections, and a `*' for each 2K of data downloaded.
(If you want to refresh GDB data on symbols or on the
executable file without downloading, use the GDB commands
symbol-file. These commands, and
itself, are described in section Commands to specify files.)
(eg-C:\H8300\TEST) gdb t.x GDB is free software and you are welcome to distribute copies of it under certain conditions; type "show copying" to see the conditions. There is absolutely no warranty for GDB; type "show warranty" for details. GDB 5.1.1, Copyright 1992 Free Software Foundation, Inc... (gdb) target hms Connected to remote H8/300 HMS system. (gdb) load t.x .text : 0x8000 .. 0xabde *********** .data : 0xabde .. 0xad30 * .stack : 0xf000 .. 0xf014 *
At this point, you're ready to run or debug your program. From here on,
you can use all the usual GDB commands. The
sets breakpoints; the
run command starts your program;
x display data; the
resumes execution after stopping at a breakpoint. You can use the
help command at any time to find out more about GDB commands.
Remember, however, that operating system facilities aren't available on your development board; for example, if your program hangs, you can't send an interrupt--but you can press the RESET switch!
Use the RESET button on the development board
In either case, GDB sees the effect of a RESET on the development board as a "normal exit" of your program.
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