This is a structure declared with bit fields and the structure members are called bit fields: A
bit field is set up with a structure declaration that labels each field and determines its width. The above definition causes PhysPageEntry
to contain one 6-bit field and one 26
bit field members namely skip
and ptr
respectively. Its signature is
struct
{
type [member_name] : width ;
};
Here width is the number of bits in the bit-field. The width must be less than or equal to the bit width of the specified type.