AnyPS5/docs/dev/debt/libSceSystemService.md

# libSceSystemService technical debt

### Silent stubs

- [libSceSystemService](../../../core/libs/prx/libSceSystemService/Export.cpp) - `sceSystemServicePowerTick`, `sceSystemServiceReportAbnormalTermination`, `sceSystemServiceDisableMusicPlayer`, `sceSystemServiceReenableMusicPlayer`, `sceSystemServiceDisableMediaPlay` and `sceSystemServiceReenableMediaPlay` return success and do nothing: the host has no auto power-off timer to reset, no system crash reporter to notify, no system music player to pause or resume and no system media playback to disable. PPSA01521 calls `sceSystemServiceDisableMediaPlay` during start-up, and its wrappers for both pass no arguments
- [sceSystemServiceLaunchWebBrowser](../../../core/libs/prx/libSceSystemService/Export.cpp) (libSceSystemService) - AnyPS5 launches no web browser, so the call fails and nothing is shown. RommPS PPSA76677 then tells the player to scan its QR code instead
- [sceSystemServiceShowControllerSettings](../../../core/libs/prx/libSceSystemService/Export.cpp) (libSceSystemService) - returns success without showing the controller settings: AnyPS5 has no system UI to open. Cat Quest III (PPSA15065) imports it
- [sceSystemServiceOpenChallengeActivity](../../../core/libs/prx/libSceSystemService/Export.cpp) (libSceSystemService) - returns success without opening the challenge activity: AnyPS5 has no system UI to open. Cat Quest III (PPSA15065) imports it

### Unknown function info

- [sceSystemServiceLaunchApp](../../../core/libs/prx/libSceSystemService/Export.cpp) (libSceSystemService) - AnyPS5 runs one title and cannot start another, so every call throws without reading its arguments. The (title ID, null-terminated argv, launch parameters) signature follows [SharpProspero](https://github.com/SvenGDK/SharpProspero/blob/5dfdb4b0b166e83dc9ae275001afb695f12c7174/src/SharpProspero/Interop/SystemService/SystemService.cs#L141-L148), whose `AppLauncher` Prospero Explorer (PPSA99109) and Prospero Multi Tools (PPSA99110) import it through and which passes a 0x20-byte launch context or null; the console's argument checks and errors are unknown
- [sceSystemServiceLaunchWebBrowser](../../../core/libs/prx/libSceSystemService/Export.cpp) (libSceSystemService) - the console's error for an unavailable web browser is unknown; it returns the kernel's `EOPNOTSUPP` (0x8002002D) for any arguments. The (uri, param) signature follows [RommPS](https://github.com/s0liton/RommPS/blob/754d4d60f25938a5136b9e2efcd074313c4386c5/platform/ps5/app/rommps/examples/rommps/kit/credits.cpp#L86-L95), which passes a URL and a null param and only tests the result for zero; the param layout and the console's argument checks are unknown
- [sceSystemServiceParamGetString](../../../core/libs/prx/libSceSystemService/Export.cpp) (libSceSystemService) - the system name (parameter 6) is the fixed `PS5`, not the console's name; other parameters and buffers of 1 to 64 bytes throw. PPSA26344 at `0xA87935` passes parameter 6 with a 65-byte buffer
- [sceSystemServiceParamGetInt](../../../core/libs/prx/libSceSystemService/Export.cpp) (libSceSystemService) - console language numbers 0 to 29 follow the PS4 SDK enum in [OpenOrbis](https://github.com/OpenOrbis/OpenOrbis-PS4-Toolchain/blob/06fcf7fd108fa080035cdd3259ed22eb07e0508c/include/orbis/_types/sys_service.h#L54-L83) (21 Arabic). 30 (Ukrainian) is not in it and follows PPSA99505 ([Jelly5](https://github.com/02dnot/Jelly5/blob/552b866d89b2a58b27f7f7b0484dc743ce235526/app/src/app/i18n.cpp#L29-L60)) and PPSA99002 ([ProsperoLight](https://github.com/blackbearreloaded/ProsperoLight/blob/b708bbde3457bef1073a9ab6959957cb691e8e2f/include/i18n.hpp#L252-L309)), whose numbers agree with the enum. Not confirmed on a console, and neither title starts on `main` yet. Parameter 400 returns the same number as parameter 1: PPSA01325 asks for 400 first, asks for 1 when that fails, and uses either answer as an index into the same 31 languages; in the PS5 10.01 and 12.60 `libSceSystemService` modules parameter 400 reads the same registry value as parameter 1, without parameter 1's mapping of newer language numbers by SDK version, and returns 0x80a10003 when an imported check that is not identified returns 1; the 4.03 module has no parameter 400. Neither the mapping nor that error is modelled, and the parameter's name is not known. Without `ANYPS5_LANGUAGE` the language is English (United States); the date format, time format, time zone, summer time and enter button stay fixed

### Functional

- [sceSystemServiceLoadExec](../../../core/libs/prx/libSceSystemService/Export.cpp) (libSceSystemService) - besides `"exit"`, it starts the title's own `/app0/eboot.bin` or another executable under `/app0` that the relinker converted with `--executable`, which is looked up beside the running one (`/app0/picker/picker.bin` as `picker.picker.bin` with the running executable's extension). The main executable is the one `APS5_EBOOT` names, which the first call sets to its own path. After the guest shutdown the old process ends without running guest exit handlers or host destructors. `"exit"` ends the process after the host shutdown without running the title's `atexit` and `__cxa_atexit` handlers, since the console's shell closes the title instead; a line the title writes just before through its own thread, such as a forwarded standard error line, may not be printed. [VLC for PS5](https://github.com/ZiZc3/VLC/blob/86bb7d474a303f62bb3c2fc12f728db4846085b8/src/platform_ps5.c#L565-L571) (PPSA85300) relaunches itself with no arguments; RetroArch (PPSA99169) starts its frontend picker with `{"", NULL}`, and the picker starts `eboot.bin` with `{"--ps5-mode=retroarch", NULL}` or `/app0/es-de/es-de.bin` ([picker.cpp](https://github.com/mihawk-99/PS5_RetroArch/blob/bead80725cc11e3c5c65bd9424b0a4494ae36d45/frontends/picker/picker.cpp#L444-L446)), so the list holds only arguments. A list with a first entry becomes the whole guest `argv`, with no program name in front ([LoadExec.cpp](../../../core/libs/prx/libSceSystemService/LoadExec.cpp)): a [PS5 RetroArch console transcript](https://github.com/mihawk-99/PS5_RetroArch/blob/bead80725cc11e3c5c65bd9424b0a4494ae36d45/evidence/loadexec-second-image/relaunch-test.jsonl) records a restart with one argument entering with `argc=1`, `argv[0]="--ps5-relaunch=1"`, and a launch from the home screen with `argc=1`, `argv[0]=""` ([relaunch_ps5.cpp](https://github.com/mihawk-99/PS5_RetroArch/blob/bead80725cc11e3c5c65bd9424b0a4494ae36d45/src/relaunch_ps5.cpp#L161-L164)). For such a list Linux replaces the process with `fexecve`: the PID and the standard streams stay, the other descriptors are closed and the working directory becomes the executable's. Windows starts a suspended process that inherits only the standard streams and a handle of the old process, and its entry stub waits for the old process to end before it loads the title's libraries, so a shell or script that started the title sees it end. A null list or one without a first entry keeps the earlier launch: the new executable gets only its own path as its command line (`CreateProcessW` on Windows, `execv` on Linux), so its `argv[0]` is the host path, and the old process ends without waiting for it. What the console passes for such a list is not known, nor are its argument limits and error codes. Paths outside `/app0`, unconverted executables and macOS hosts throw
- [Running application ID](../../../core/libs/prx/libSceSystemService/Export.cpp) (libSceSystemService) - `sceSystemServiceGetAppIdOfRunningBigApp` reports 1 as the running title's app ID. The value is AnyPS5's own: the console's shell assigns app IDs and their values are not known here, so other calls that take an app ID must use the same one. `sceSystemServiceKillApp` with that ID and the arguments -1, 0 and 0, which [SwanStationPS5](https://github.com/darkxex/SwanStationPS5/blob/4cdc981d1a64ffb7f2af73f7a27a9e91a3cb5eb4/src/main.c#L1050-L1058) passes to close itself and [ps5-payload-dev's hbldr](https://github.com/ps5-payload-dev/websrv/blob/46374edee6627885abac717de24da7a1d73af6f1/src/ps5/hbldr.c#L425-L435) passes to close the running game, ends the title as its own `exit(0)` would: the guest's shutdown and `atexit` handlers run and the process exits with status 0. On the console the call returns and the shell then ends the title, and whether those handlers run there is unknown; here there is no shell, so the call does not return. Another app ID or other arguments throw.
- [LoadExec descriptors](../../../core/libs/prx/libSceSystemService/LoadExec.cpp) (libSceSystemService) - on Linux, a call with an argument list replaces the process with `fexecve`, which first closes every descriptor above 2; a call without one uses `execv`, and the guest's descriptors stay open across it. On both paths descriptor 2 first gets back the host standard error a guest redirect kept, so the runtime's output does not follow the title's redirect (RetroArch's trace file, VLC's log) into the next executable. Which descriptors the console passes to the new process is not known