F. Target Descriptions

Warning: target descriptions are still under active development, and the contents and format may change between No value for GDBN releases. The format is expected to stabilize in the future.

One of the challenges of using No value for GDBN to debug embedded systems is that there are so many minor variants of each processor architecture in use. It is common practice for vendors to start with a standard processor core — ARM, PowerPC, or MIPS, for example — and then make changes to adapt it to a particular market niche. Some architectures have hundreds of variants, available from dozens of vendors. This leads to a number of problems:

• With so many different customized processors, it is difficult for the No value for GDBN maintainers to keep up with the changes.
• Since individual variants may have short lifetimes or limited audiences, it may not be worthwhile to carry information about every variant in the No value for GDBN source tree.
• When No value for GDBN does support the architecture of the embedded system at hand, the task of finding the correct architecture name to give the set architecture command can be error-prone.

To address these problems, the No value for GDBN remote protocol allows a target system to not only identify itself to No value for GDBN, but to actually describe its own features. This lets No value for GDBN support processor variants it has never seen before — to the extent that the descriptions are accurate, and that No value for GDBN understands them.

No value for GDBN must be compiled with Expat support to support XML target descriptions. See Expat.