F.2 Target Description Format

A target description annex is an XML document which complies with the Document Type Definition provided in the No value for GDBN sources in ‘gdb/features/gdb-target.dtd’. This means you can use generally available tools like xmllint to check that your feature descriptions are well-formed and valid. However, to help people unfamiliar with XML write descriptions for their targets, we also describe the grammar here.

Target descriptions can identify the architecture of the remote target and (for some architectures) provide information about custom register sets. No value for GDBN can use this information to autoconfigure for your target, or to warn you if you connect to an unsupported target.

Here is a simple target description:

<target version="1.0">
  <architecture>i386:x86-64</architecture>
</target>

This minimal description only says that the target uses the x86-64 architecture.

A target description has the following overall form, with [ ] marking optional elements and … marking repeatable elements. The elements are explained further below.

<?xml version="1.0"?>
<!DOCTYPE target SYSTEM "gdb-target.dtd">
<target version="1.0">
  [architecture]
  [feature…]
</target>

The description is generally insensitive to whitespace and line breaks, under the usual common-sense rules. The XML version declaration and document type declaration can generally be omitted (No value for GDBN does not require them), but specifying them may be useful for XML validation tools. The ‘version’ attribute for ‘<target>’ may also be omitted, but we recommend including it; if future versions of No value for GDBN use an incompatible revision of ‘gdb-target.dtd’, they will detect and report the version mismatch.