This also may eventually allow loading patches from sources other than the 1:1 expected file structure host file system, such as memory or an archive file.
Retail-signed discs use the format: IOS56-64-v5661.wad
Debug-signed discs use the format: firmware.64.56.22.29.wad
Debug-signed discs usually have a 128 version of the firmware as well,
since some devkits have 128 MB MEM2. (Retail has 64 MB.)
The workaround added in 30f9f31 caused a regression where Dolphin
incorrectly replaced runs of one byte with runs of another byte
when writing WIA and RVZ files. ReuseID::operator< was always
returning false unless the ReuseIDs being compared had different
partition keys, which caused std::map<ReuseID, GroupEntry>
to treat all ReuseIDs with the same partition key as equal.
Public domain does not have an internationally agreed upon definition,
As such it's generally preferred to use an extremely liberal license,
which can explicitly list the rights granted by the copyright holder.
The CC0 license is the usual choice here.
This "relicensing" is done without hunting down copyright holders, since
it is presumed that their release of this work into the public domain
authorizes us to redistribute this code under any other license of our
choosing.
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.
This improves the speed of verifying Wii WIA/RVZ files.
For me, the verification speed for LZMA2-compressed files
has gone from 11-12 MiB/s to 13-14 MiB/s.
One thing VolumeVerifier does to achieve parallelism is to
compute hashes for one chunk of data while reading the next
chunk of data. In master, when reading data from a Wii
partition, each such chunk is 32 KiB. This is normally fine,
but with WIA and RVZ it leads to rather lopsided read times
(without the compute times being lopsided): The first 32 KiB
of each 2 MiB takes a long time to read, and the remaining
part of the 2 MiB can be read nearly instantly. (The WIA/RVZ
code has to read the entire 2 MiB in order to compute hashes
which appear at the beginning of the 2 MiB, and then caches
the result afterwards.) This leads to us at times not doing
much reading and at other times not doing much computation.
To improve this, this change makes us use 2 MiB chunks
instead of 32 KiB chunks when reading from Wii partitions.
(block = 32 KiB, group = 2 MiB)
This can't actually happen in practice due to how WAD files work,
but it's very easy to add support for thanks to the last commit,
so we might as well add support for it.
The performance gains of doing this aren't too important since you
normally wouldn't run into any disc image that has overlapping blocks
(which by extension means overlapping partitions), but this change also
lets us get rid of things like VolumeVerifier's mutex that used to
exist just for the sake of handling overlapping blocks.
Panic alerts in DiscIO can potentially be very annoying since
large amounts of them can pop up when loading the game list
if you have some particularly weird files in your game list.
This was a much bigger problem back in 5.0 with its
"Tried to decrypt data from a non-Wii volume" panic alert, but
I figured I would take it all the way and remove the remaining
panic alerts that can show up when loading the game list.
I have exempted uses of ASSERT/ASSERT_MSG since they indicate
a bug in Dolphin rather than a malformed file.
