Function layout 

pub fn layout(
    budget: &Budget,
    cx: &Context,
    slots: &mut [Slot],
    powers: Powers,
    bg: Background,
) -> BackgroundUsed

The DSig paper’s background: the given values, or the planner’s.

Automatic: the EdDSA share and its sign/verify split that deliver the most for the mix with every module in its guaranteed share. Too little EdDSA starves the certificates or the cache misses; too much takes area from the HBSS. The best share is how much EdDSA DSig actually needs at this budget, best case and batch size, and is shown as “needed”.