> +/// A special `MemTxAttrs` constant, used to indicate that no memary typo... s/memary/memory/
> +/// attributes are specified.
> +///
> +/// Bus masters which don't specify any attributes will get this,
> +/// which has all attribute bits clear except the topmost one
> +/// (so that we can distinguish "all attributes deliberately clear"
> +/// from "didn't specify" if necessary).
> +pub const MEMTXATTRS_UNSPECIFIED: MemTxAttrs = MemTxAttrs {
> + unspecified: true,
> + ..Zeroable::ZERO
> +};
