SPDX standardizes how source code conveys its copyright and licensing
information. See https://spdx.github.io/spdx-spec/1-rationale/ . SPDX
tags are adopted in many large projects, including things like the Linux
kernel.
It's possible (but rare) for a WIA or RVZ file to support
this for some partitions but not all, and for the game and
the blob code to disagree on how large a partition is.
This is intended to catch WIA files which have been created using
wit's default parameters (40 MiB block size), once the WIA PR is
merged. The check does however also work for GCZ files – not that
I think anyone has a GCZ file with a block size that large.
For instance, we don't want to show TGC files that might be
inside the /files/ directory of a GameCube DirectoryBlob,
and we don't want to show the /sys/main.dol files for extra
partitions of Wii DirectoryBlobs.
Now it's clearer that SetDOL depends on SetApploader
and BuildFST depends on SetDOL.
As a side note, we now load the DOL even if there's
no apploader. (I don't think it matters whether we
do it, but it was easier to implement this way.)
This lets VolumeDirectory/DirectoryBlob skip implementing
various volume functions like GetGameID, GetBanner, etc.
It also lets us view extracted discs in the game list.
This ends up breaking the boot process for Wii
DirectoryBlobs due to workarounds being removed from the
boot process, but that will be fixed later by adding
proper DirectoryBlob support for things like TMDs.
We now expect the directories to be laid out in a certain
format (based on the format that WIT uses) instead of requiring
the user to set the DVD root and apploader path settings.