[SleglJan]

What

Adds sceKernelGetFsSandboxRandomWord to libkernel, in a new System/src/Sandbox.cpp. On the console a title's sandbox root holds app0 and a directory with a random-looking name under which system files are exposed; the function returns that name, and the open-source SDKs splice it into paths: /<name>/common/cert/CA_LIST.cer (ProsperoEden), /<name>/common/lib/libc.sprx (tiny-ps4-shell), /<name>/common/lib/mscorlib.dll (ps4-hen-plugins). The kernel keeps the name per process and randomized_path (syscall 602) reads it back, as obliteration implements it, with /system/common/lib mounted at <name>/common/lib.

• The name is fixed, gkbHtXc3Wq, so a path built from it is the same across runs. It is recorded in TechnicalDebt: nothing is mounted under the name here, so /gkbHtXc3Wq/common/... resolves under the guest root like any other path and does not exist.
• The pointer is to static storage and the same on every call and every thread; the function cannot fail.

In the Linux audit of the homebrew catalog (boykopovar#1578), the function was absent for 12 of the 34 relinked titles.

Overlap: none by tools/pr_overlap.py against the open pull requests. boykopovar#1748, boykopovar#1650 and boykopovar#1675 change System/src/Process.cpp, which this does not touch; the source line goes after Process.cpp in libkernel/CMakeLists.txt, the test block after guest_file_vector, and the TechnicalDebt entry after the sceKernelPread one, clear of boykopovar#1802's rewrite of the sceKernelRaiseException entries.

Tested

• Linux (CachyOS, kernel 7.2.9, GCC 16.2.1), full build with BUILD_TESTING=ON and ANYPS5_ENABLE_SPIRV_TOOLS=ON on this branch (based on main b858fdc): ctest --repeat until-fail:3 487/487; tools/check_test_registration.py and tools/check_conventions.py --base upstream/main pass.
• New guest_sandbox_random_word test: a non-null, non-empty alphanumeric name, the same pointer on a second call and from another thread, and open of /<name>/common/lib/libc.sprx failing with ENOENT. Written before the implementation; it failed on the unresolved export and passes with it.
• The patched libkernel.prx exports the NID (JGfTMBOdUJo).
• tools/import_audit.py on four of the 12 catalog titles, absent imports on main b858fdc → this branch: PPSA17641 SymphonyStation5 35 → 34, PPSA97510 PSXS5 72 → 71, PPSA99009 ProsperoLichess 37 → 36, PPSA99082 OpenNOW PS5 - Prototype 36 → 35; the one that disappears is this function each time. No title was run, since each still has other absent imports, listed in Four open-source homebrew titles stop at start-up on unresolved imports (sysctl, pthread_set_name_np, isatty, mkstemp, signal sets, Opus decoders) boykopovar/AnyPS5#1578.
• Windows: WINDOWSLINE

Checklist

• Based on current main; no other open PR implements the same functions
• One topic per PR; follow-ups go in a new PR
• No comments in code except technical debt
• Unimplemented paths throw (NotImplemented_nid_no_patch); silent stubs are listed in TechnicalDebt
• No notes, investigation .md files or images added to the repository (attach them to this PR)
• New third-party code is a submodule built from source
• Generic behaviour, not specific to one title
• Depends on: none
• AI-assisted: yes (Claude Code)

🤖 Generated with Claude Code