huge changes to everything (see below).

Changelog:
- re-enable use in release build.
- remove ftpsrv and untitled from builtin ghdl options, as both packages are available in the appstore.
- add image viewer (png, jpg, bmp)
- add music player (bfstm, bfwav, mp3, wav, ogg)
- add idv3 tag parsing support for mp3.
- add "decyption" of GTA Vice City mp3.
- add usbdvd support for music playback and file browsing.
- add nsz export support (solid, block, ldm).
- add xcz export support (same as above).
- add nro fs proper mount support (romfs, nacp, icon).
- add program nca fs support.
- add bfsar fs support.
- re-write the usb protocol, still wip. replaces tinfoil protocol.
- all threads are now create with pre-emptive support with the proper affinity mask set.
- fix oob crash in libpulsar when a bfwav was opened that had more than 2 channels.
- bump yyjson version.
- bump usbhsfs version.
- disable nvjpg.
- add support for theme music of any supported playback type (bfstm, bfwav, mp3, wav, ogg).
- add support for setting background music.
- add async exit to blocking threads (download, nxlink, ftpsrv) to reduce exit time.
- add support for dumping to pc via usb.
- add null, deflate, zstd hash options, mainly used for benchmarking.
- add sidebar slider (currently unused).
- file_viwer can now be used with any filesystem.
- filebrowser will only ever stat file once. previously it would keep stat'ing until it succeeded.
- disabled themezer due to the api breaking and i am not willing to keep maintaining it.
- disable zlt handling in usbds as it's not needed for my api's because the size is always known.
- remove usbds enums and GetSpeed() as i pr'd it to libnx.
- added support for mounting nca's from any source, including files, memory, nsps, xcis etc.
- split the lru cache into it's own header as it's now used in multiple places (nsz, all mounted options).
- add support for fetching and decrypting es personalised tickets.
- fix es common ticket converting where i forgot to also convert the cert chain as well.
- remove the download default music option.
- improve performance of libpulsar when opening a bfsar by remove the large setvbuf option. instead, use the default 1k buffer and handle large buffers manually in sphaira by using a lru cache (todo: just write my own bfsar parser).
- during app init and exit, load times have been halved as i now load/exit async. timestamps have also been added to measure how long everything takes.
- download now async loads / exits the etag json file to improve init times.
- add custom zip io to dumper to support writing a zip to any dest (such as usb).
- dumper now returns a proper error if the transfer was cancelled by the user.
- fatfs mount now sets the timestamp for files.
- fatfs mount handles folders with the archive bit by reporting them as a file.
- ftpsrv config is async loaded to speed up load times.
- nxlink now tries attempt to connect/accept by handling blocking rather than just bailing out.
- added support for minini floats.
- thread_file_transfer now spawns 3 threads rather than 2, to have the middle thread be a optional processor (mainly used for compressing/decompressing).
- added spinner to progress box, taken from nvg demo.
- progress box disables sleep mode on init.
- add gamecard detection to game menu to detect a refresh.
- handle xci that have the key area prepended.
- change gamecard mount fs to use the xci mount code instead of native fs, that way we can see all the partitions rather than just secure.
- reformat the ghdl entries to show the timestamp first.
- support for exporting saves to pc via usb.
- zip fs now uses lru cache.

sphaira/include/usb/usb_uploader.hpp

@@ -13,25 +13,30 @@ struct Usb {
     Usb(u64 transfer_timeout);
     virtual ~Usb();
 
-    virtual Result Read(const std::string& path, void* buf, s64 off, s64 size, u64* bytes_read) = 0;
+    virtual Result Read(void* buf, u64 off, u32 size, u64* bytes_read) = 0;
+    virtual Result Open(u32 index, s64& out_size, u16& out_flags) = 0;
 
     Result IsUsbConnected(u64 timeout) {
         return m_usb->IsUsbConnected(timeout);
     }
 
     // waits for connection and then sends file list.
-    Result WaitForConnection(u64 timeout, u8 flags, std::span<const std::string> names);
+    Result WaitForConnection(u64 timeout, std::span<const std::string> names);
 
     // polls for command, executes transfer if possible.
     // will return Result_Exit if exit command is recieved.
     Result PollCommands();
 
-private:
-    Result FileRangeCmd(u64 data_size);
+    Result file_transfer_loop();
 
 private:
-    std::unique_ptr<usb::UsbHs> m_usb;
-    std::vector<u8> m_buf;
+    Result SendResult(u32 result, u32 arg3 = 0, u32 arg4 = 0);
+
+private:
+    std::unique_ptr<usb::UsbHs> m_usb{};
+    std::vector<u8> m_buf{};
+    Result m_open_result{};
+    bool m_was_connected{};
 };
 
 } // namespace sphaira::usb::upload