+
+ The optional callback functions are:
+ - [?argcheck] called after arguments have been fully parsed
+ so that the program can do any additional checks needed (eg.
+ on [extra_args]),
+ - [?beforeksyms] called after images are loaded and before
+ kernel symbols are analyzed,
+ - [?run] called after kernel symbols have been analyzed
+ (almost all tools supply this callback function).
+
+ Pass [~external_cmd:false] if this tool doesn't have an
+ external 'virt-tool' link.
+
+ Pass [~extra_args:...] if this tool needs extra command
+ line options.