Fixes a regression from #4862, which caused the NCCH title ID checking
heuristic to be skipped whenever the exheader is replaced.
I was thinking the heuristic wouldn't be needed in that case, but it
turns out that many users still have pathological NCCHs that indicate
they are encrypted but are actually decrypted...
Now the original exheader is always read and used for the heuristic
to determine whether the NCCH is actually encrypted; only then do we
load a replacement exheader (if it exists) to avoid affecting the
heuristic.
Require and assume that override exheaders are decrypted for
consistency with Luma's loader behaviour and to ensure consistent
behaviour regardless of whether the NCCH is marked as encrypted or not.
Currently, exheader overriding with an encrypted NCCH would cause
the title ID checking heuristic to mistakenly disable encryption,
which would then make exefs loading fail.
This allows an IPS patch to edit .bss. This is useful for game patches
that need to add code, as putting things in .bss allows adding new code
*without* editing .code and thus without having to relocate everything.
Currently, having a replacement code.bin causes Citra to crash as it is
trying to load icon data from code.bin because of a typo. This commit
fixes that typo.
These kinds of casts invoke undefined behavior, due to both the aliasing
rule, and from an alignment point-of-view. Use the way that's guaranteed
to always work instead.
* loader/ncch: split NCCH parsing into its own file
* loader/ncch: add support for loading update NCCHs from the SD card
* loader/ncch: fix formatting
* file_sys/ncch_container: Return a value for OpenFile
* loader/ncch: cleanup, always instantiate overlay_ncch to base_ncch
* file_sys/ncch_container: better encryption checks, allow non-app NCCHs to load properly and for the existence of NCCH structures to be checked
* file_sys/ncch_container: pass filepath as a const reference
