Target descriptions can be read from the target automatically, or specified by the user manually. The default behavior is to read the description from the target. GDB retrieves it via the remote protocol using ‘qXfer’ requests (see qXfer). The annex in the ‘qXfer’ packet will be ‘target.xml’. The contents of the ‘target.xml’ annex are an XML document, of the form described in Target Description Format.
Alternatively, you can specify a file to read for the target description. If a file is set, the target will not be queried. The commands to specify a file are:
set tdesc filename path
Read the target description from path.
unset tdesc filename
Do not read the XML target description from a file. GDB will use the description supplied by the current target.
show tdesc filename
Show the filename to read for a target description, if any.