F.2.4 Types

Any register's value is a collection of bits which No value for GDBN must interpret. The default interpretation is a two's complement integer, but other types can be requested by name in the register description. Some predefined types are provided by No value for GDBN (see section Predefined Target Types), and the description can define additional composite types.

Each type element must have an ‘id’ attribute, which gives a unique (within the containing ‘<feature>’) name to the type. Types must be defined before they are used.

Some targets offer vector registers, which can be treated as arrays of scalar elements. These types are written as ‘<vector>’ elements, specifying the array element type, type, and the number of elements, count:

<vector id="id" type="type" count="count"/>

If a register's value is usefully viewed in multiple ways, define it with a union type containing the useful representations. The ‘<union>’ element contains one or more ‘<field>’ elements, each of which has a name and a type:

<union id="id">
  <field name="name" type="type"/>
  …
</union>