D099 - Package entries derivable here are computed

Status: decided Date: 2026-09-26

The package builder computes entry 0x200 (the names of the entries present) and entry 0x1001 (the single-chunk playgo-chunk.dat, from data/pkg-format.tsv, the package size and the inner filesystem size read from the image) when the caller does not supply them. A supplied one is used as given.

Why: both are fixed structures whose variable parts the builder already holds, so requiring them asks the caller to hand back facts the builder has. Rebuilding an existing package byte for byte still needs its own entries.

Rejected:

• Requiring them from the caller: callers without them hardcode or guess.
• Ignoring a supplied entry: prevents reproducing existing material.