AnyPS5/docs/dev/debt/libSceFios2.md

libSceFios2 technical debt

Functional

• libSceFios2 prototypes (libSceFios2) - the implemented exports take the prototypes of RPCS3's Vita FIOS2 module (Emu/ARMv7/Modules/sceFios.h and sceFios.cpp, jacquesjk/RPCS-DX12 at 9b8b7c9eea446095f24af19182032013837e6ca5, 64-bit types substituted), checked against the PS4 headers and call sites of kalaposfos13/fios2 (src/fios2.h, ae6ca1d78e7a822c2528f7660959167b9b3d8b63), sonny-tel/libSceFios2 (sceFios2.h, 5d44f9e7a80ae00557af80fad335e4c74ef35d22), Inori/GPCS4 (SceFios2/sce_fios2.cpp) and SonicMastr/SceLibcPosix (src/internal/fios2.h, Vita, c2cd5e880a8770bdbfb58de761de11f396c1a2e7). The SceFiosOpAttr, SceFiosOpenParams, SceFiosStat and SceFiosDirEntry layouts and the SCE_FIOS_ERROR_* values (0x80820000 plus the enumeration order) come from the same sources; vascon-es/lego-dimensions-pc confirms the SceFiosStat and SceFiosDirEntry offsets and the fileSize, statFlags bit 0 (directory) and offsetToName reads from the call sites of a PS4 title. None of it was measured on a PS5. The SceFiosOpenParams buffer sits at offset 8 in kalaposfos13 and sonny-tel and at offset 0x10 in lego-dimensions-pc; only openFlags is read
• Operations (libSceFios2) - there are no I/O or decompressor threads. An operation runs on the calling thread and is complete when the export returns, and its callback fires there with SCE_FIOS_OPEVENT_COMPLETE; while sceFiosSuspend is in effect new operations queue and run on the thread whose sceFiosResume ends the suspension. deadline, priority, opflags, userTag, userPtr and the scheduler fields are stored and returned but have no effect, and SCE_FIOS_OPEVENT_START is never sent. The *Sync exports are the asynchronous export followed by sceFiosOpSyncWait, so they also fire the completion and SCE_FIOS_OPEVENT_DELETE callbacks. sceFiosOpSyncWait returns the error or the low 32 bits of the result (1 or 0 for the existence queries, as in kalaposfos13/fios2), sceFiosOpGetActualCount returns the result (the size for sceFiosFileGetSize) also for a failed operation, and sceFiosOpGetError returns 1 while an operation is queued; none of these is measured. Handles of operations, files and directories share one number space that starts at 1. Nothing requires sceFiosInitialize first, and SceFiosParams is stored as paramsSize bytes (the 15 bits at bit 1 of the first word) without interpretation, so the storage buffers, pathMax (1024 is used), thread and scheduler settings are ignored
• sceFiosExists, sceFiosFileExists, sceFiosDirectoryExists, sceFiosFileGetSize, sceFiosStat and their Sync forms (libSceFios2) - paths go to sceKernelStat, so archive and alias mapping is the kernel's. A missing path is not an error for the existence queries. SceFiosStat carries only the sizes, the nanosecond dates as seconds since 1970 times 10^9 plus nanoseconds (the epoch and unit are not measured), statFlags bit 0 for a directory, and the kernel st_uid, st_gid, st_dev, st_ino and st_mode; other statFlags bits are 0. sceFiosFileExists and sceFiosDirectoryExists take the pOutExists argument of RPCS3's prototype, which kalaposfos13/fios2 omits, and sceFiosFileGetSize has no output pointer as in kalaposfos13/fios2 and sonny-tel (RPCS3 declares one)
• sceFiosDelete, sceFiosFileDelete, sceFiosDirectoryCreate, sceFiosDirectoryDelete, sceFiosRename, sceFiosFileRead, sceFiosFileWrite, sceFiosFileTruncate and their Sync forms (libSceFios2) - behaviour is inferred from the export names; none of it is measured. They run on sceKernelStat, sceKernelOpen, sceKernelPread, sceKernelPwrite, sceKernelFtruncate, sceKernelMkdir, sceKernelRmdir, sceKernelUnlink and sceKernelRename, so guest path mapping and the read-only application directory are the kernel's. sceFiosFileWrite opens the file write-only with creation and no truncation, sceFiosFileTruncate does not create it, directories are created with mode 0777 and files with 0666, sceFiosDelete removes a file or an empty directory, and a negative length returns SCE_FIOS_ERROR_BAD_SIZE, a negative offset SCE_FIOS_ERROR_BAD_OFFSET. A read stops at the end of the file and returns the bytes read. The mapping of kernel errors to SCE_FIOS_ERROR_* is chosen here: ENOENT and ENOTDIR to BAD_PATH, EPERM, EACCES and ENOTEMPTY to ACCESS, EROFS to READ_ONLY, EEXIST to ALREADY_EXISTS, EISDIR to NOT_A_FILE, EINVAL to BAD_OFFSET, ENFILE and EMFILE to CANT_ALLOCATE_FH, ENAMETOOLONG to PATH_TOO_LONG, EFAULT to BAD_PTR, and anything else to UNKNOWN. The prototypes follow RPCS3 (sceFios.cpp sceFiosFileWrite, sceFiosFileTruncate, sceFiosRename, sceFiosDelete) and kalaposfos13/fios2 (sceFiosFileRead)
• sceFiosFHOpen, sceFiosFHOpenWithMode, sceFiosFHClose, sceFiosFHStat, sceFiosFHTruncate, sceFiosFHSync, sceFiosFHRead, sceFiosFHWrite, sceFiosFHPread, sceFiosFHPwrite, the vectored forms with their Sync forms, sceFiosFHSeek, sceFiosFHTell, sceFiosFHGetSize, sceFiosFHGetPath and sceFiosFHGetOpenParams (libSceFios2) - a file handle owns one kernel descriptor, and sceFiosFHRead, sceFiosFHWrite, sceFiosFHSeek and sceFiosFHTell use its kernel position. openFlags map as SCE_FIOS_O_READ 1, SCE_FIOS_O_WRITE 2, SCE_FIOS_O_APPEND 4, SCE_FIOS_O_CREAT 8 and SCE_FIOS_O_TRUNC 16 (sonny-tel/libSceFios2, SonicMastr/SceLibcPosix); SCE_FIOS_O_DIRECT (1 << 12) is ignored, no flags or null parameters open read-only, and the handle returns SCE_FIOS_ERROR_WRITE_ONLY or SCE_FIOS_ERROR_READ_ONLY for a transfer its flags exclude (the console result is not measured). The creation mode is 0777 unless sceFiosFHOpenWithMode is given one (-1 means the default, as in kalaposfos13/fios2). Opening a directory returns SCE_FIOS_ERROR_NOT_A_FILE. An invalid whence or a negative resulting position returns SCE_FIOS_ERROR_BAD_OFFSET, a vector count outside 1 to 1024 SCE_FIOS_ERROR_BAD_IOVCNT. The Readv and Writev exports transfer the vectors in order and stop at the first short one. sceFiosFHGetPath and sceFiosFHGetOpenParams return pointers that stay valid until the handle is closed; the stored SceFiosOpenParams has no buffer. The handle prototypes follow RPCS3's sceFios.cpp and kalaposfos13/fios2; sceFiosFHToFileno and sceFiosFilenoToFH have no source and keep throwing

Unknown function info

• sceFiosArchiveGetDecompressorThreadCount, sceFiosArchiveGetMountBufferSize, sceFiosArchiveGetMountBufferSizeSync, sceFiosArchiveMount, sceFiosArchiveMountSync, sceFiosArchiveMountWithOrder, sceFiosArchiveMountWithOrderSync, sceFiosArchiveSetDecompressorThreadCount, sceFiosArchiveUnmount, sceFiosArchiveUnmountSync, sceFiosCacheContainsFileRangeSync, sceFiosCacheContainsFileSync, sceFiosCacheFlushFileRangeSync, sceFiosCacheFlushFileSync, sceFiosCacheFlushSync, sceFiosCachePrefetchFH, sceFiosCachePrefetchFHRange, sceFiosCachePrefetchFHRangeSync, sceFiosCachePrefetchFHSync, sceFiosCachePrefetchFile, sceFiosCachePrefetchFileRange, sceFiosCachePrefetchFileRangeSync, sceFiosCachePrefetchFileSync, sceFiosClearTimeStamps, sceFiosDHClose, sceFiosDHCloseSync, sceFiosDHGetPath, sceFiosDHOpen, sceFiosDHOpenSync, sceFiosDHRead, sceFiosDHReadSync, sceFiosDLLInitialize, sceFiosDLLTerminate, sceFiosDeallocatePassthruFH, sceFiosDebugDumpDH, sceFiosDebugDumpDate, sceFiosDebugDumpError, sceFiosDebugDumpFH, sceFiosDebugDumpOp, sceFiosDirectoryCreateWithMode, sceFiosDirectoryCreateWithModeSync, sceFiosFHToFileno, sceFiosFilenoToFH, sceFiosIOFilterAdd, sceFiosIOFilterCache, sceFiosIOFilterGetInfo, sceFiosIOFilterPsarcDearchiver, sceFiosIOFilterRemove, sceFiosOpReschedule, sceFiosOpRescheduleWithPriority, sceFiosOpSetBuffer, sceFiosOpWaitUntil, sceFiosOverlayAdd, sceFiosOverlayGetInfo, sceFiosOverlayGetList, sceFiosOverlayModify, sceFiosOverlayRemove, sceFiosOverlayResolveSync, sceFiosPathNormalize, sceFiosPathcmp, sceFiosPathncmp, sceFiosPrintTimeStamps, sceFiosPrintf, sceFiosResolve, sceFiosResolveSync, sceFiosSaveTimeStamp, sceFiosTimeGetCurrent, sceFiosTimeIntervalFromNanoseconds, sceFiosTimeIntervalToNanoseconds, sceFiosTraceTimestamp and sceFiosVprintf (libSceFios2) - names and NIDs are present in the PS5 3.20 export inventory, but no credible prototypes were found. The declarations have no parameters solely to resolve known imports; this is not an ABI claim and callers must not call them until signatures are verified

• sceFiosDateFromComponents, sceFiosDateGetCurrent and sceFiosDateToComponents (libSceFios2) - the date packing is unverified and the declarations in Export.cpp still carry no parameters. kalaposfos13/fios2 (src/fios2.h, PS4) and RPCS3 (Emu/PSP2/Modules/sceFios.cpp) independently declare sceFiosDateFromComponents(tm*) and sceFiosDateGetCurrent() returning a 64-bit date, sceFiosDateToComponents(int64_t, tm*) returning the tm pointer, but both may descend from one leaked Vita SDK and kalaposfos13's bodies are guesses (mktime times 1e9). sonny-tel/libSceFios2 (a header read from a Fortnite build) gives SceFiosParams, SceFiosOpAttr, SceFiosOpenParams and SceFiosStat layouts, unverified against firmware