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.
Since all FS access will go through the new FS interface (PR #6421)
in order to keep track of metadata properly, there is no need to return
absolute paths anymore.
In fact, returning host paths is a roadblock to using the FS interface.
This starts the migration work by adding a way to get paths that are
relative to the Wii NAND instead of always getting absolute paths
on the host FS.
To prepare for future changes, this commit also makes returned paths
canonical by removing the trailing slash when it's unneeded.
Eventually, once everything has been migrated to the new interface,
we can remove the "from" parameter.
This is slightly safer than writing contents to /title directly.
We still cannot rename everything in one go atomically, but this allows
implementing AddTitleCancel very easily.
Also, this ensures that when a title import fails, no incomplete files
will be left in the title directory, which can mess up the system menu.
Dolphin is able to generate one with all correct default settings, so
we don't need to ship with a pre-generated SYSCONF and worry about
syncing default settings.
Additionally, this commit changes SysConf to work with session SYSCONFs
so that Dolphin is able to generate a default one even for Movie/TAS.
Which SYSCONF needs to be touched is explicitly specified to avoid
confusion about which file SysConf is managing.
(Another notable change is that the Wii root functions are moved into
Core to prevent Common from depending on Core.)
Prevents path traversal without needing an absolute path
function, and also improves accuracy (character sequences
like ../ appear to have no special meaning in IOS).
This removes the creation and usage of /sys/replace,
because the new escapes are too complicated to all
be representable in its format and because no other
NAND handling software seems to use /sys/replace.
It's used by both the GUI to do things like install WADs and check up on
the system menu, in which case the global root should be used, and by
/dev/es, in which case the local one should. The latter isn't
*terribly* useful today, since no contents will ever be installed in
temporary roots (although it's still relevant for data directories), but
converting the whole thing makes sense because then it will Just Work
once the entire NAND is synced.
Because it would have been a bit of work to split it up (but I can if
desired), this commit also contains some basic cleanup of
NANDContentLoader:
(1) The useless interface class INANDContentLoader is removed and the
methods are changed to just return CNANDContentLoader (the only
implementation);
(2) CNANDContentManager is changed to use unique_ptr and cleaned up a
bit.
Eventually, netplay will be able to use the host's NAND, but this could
still be useful in some cases; for TAS it definitely makes sense to have
a way to avoid using any preexisting NAND.
In terms of implementation: remove D_WIIUSER_IDX, which was just WIIROOT
+ "/", as well as some other indices which are pointless to have as
separate variables rather than just using the actual path (fixed, since
they're actual Wii NAND paths) at the call site. Then split off
D_SESSION_WIIROOT_IDX, which can point to the dummy NAND directory, from
D_WIIROOT_IDX, which always points to the "real" one the user
configured.
