Debugging with GDB (September 2007)

Chapter 13: Specifying a Debugging Target 111
target nrom dev
NetROM ROM emulator. This target only supports downloading.
Different targets are available on different configurations of GDB; your configuration
may have more or fewer targets.
Many remote targets require you to download the executable code once you have suc-
cessfully established a connection.
load filename
Depending on what remote debugging facilities are configured into GDB, the
load command may be available. Where it exists, it is meant to make filename
(an executable) available for debugging on the remote system—by downloading,
or dynamic linking, for example. load also records the filename symbol table
in GDB, like the add-symbol-file command.
If your GDB does not have a load command, attempting to execute it gets the
error message “You can’t do that when your target is ...”
The file is loaded at whatever address is specified in the executable. For some
object file formats, you can specify the load address when you link the program;
for other formats, like a.out, the object file format specifies a fixed address.
load does not repeat if you press
h
RET
i
again after using it.
13.3 Choosing target byte order
Some types of processors, such as the MIPS, PowerPC, and Hitachi SH, offer the ability
to run either big-endian or little-endian byte orders. Usually the executable or symbol will
include a bit to designate the endian-ness, and you will not need to worry about which to
use. However, you can adjust the processor byte order manually using one of the following
commands:
set endian big
Instruct GDB to assume the target is big-endian.
set endian little
Instruct GDB to assume the target is little-endian.
set endian auto
Instruct GDB to use the byte order associated with the executable.
show endian
Display GDB’s current idea of the target byte order.
Note that these commands merely adjust interpretation of symbolic data on the host,
and that they have absolutely no effect on the target system.