From e2954aa188c5aaa0a93f202e72ecab58e5501ec2 Mon Sep 17 00:00:00 2001
From: David <david@example.com>
Date: Sun, 11 Oct 2026 09:42:43 +0200
Subject: [PATCH] feat(libSceNpPartner001): implement sceNpEAAccessInitialize
 and sceNpEAAccessTerminate

UFC 6 (PPSA23566) imports both. Initialization marks the library
initialized and termination clears it, as in shadPS4. Termination
without initialization and a second initialization throw, since no
PS5 source settles their results.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
(cherry picked from commit d2866a886a7702cdaad56d161460a3ce86ede629)
---
 .../prx/libSceNpPartner001/CMakeLists.txt     | 15 ++++++++
 core/libs/prx/libSceNpPartner001/Export.cpp   | 13 +++++--
 core/libs/tests/GuestNpPartner.cpp            | 34 +++++++++++++++++++
 docs/dev/debt/libSceNpPartner001.md           |  4 +++
 4 files changed, 64 insertions(+), 2 deletions(-)
 create mode 100644 core/libs/prx/libSceNpPartner001/CMakeLists.txt
 create mode 100644 core/libs/tests/GuestNpPartner.cpp

diff --git a/core/libs/prx/libSceNpPartner001/CMakeLists.txt b/core/libs/prx/libSceNpPartner001/CMakeLists.txt
new file mode 100644
index 000000000..c339e97d9
--- /dev/null
+++ b/core/libs/prx/libSceNpPartner001/CMakeLists.txt
@@ -0,0 +1,15 @@
+add_library(libSceNpPartner001 SHARED EXCLUDE_FROM_ALL Export.cpp)
+target_include_directories(libSceNpPartner001 PRIVATE ${LIBS_INCLUDE_DIR})
+configure_windows_unwind(libSceNpPartner001)
+
+if(BUILD_TESTING)
+    add_test_executable(guest_np_partner_tests ${LIBS_INCLUDE_DIR}/tests/GuestNpPartner.cpp)
+    target_include_directories(guest_np_partner_tests PRIVATE ${LIBS_INCLUDE_DIR})
+    target_link_libraries(guest_np_partner_tests PRIVATE libSceNpPartner001 libc)
+    configure_windows_unwind(guest_np_partner_tests)
+    add_test(NAME guest_np_partner COMMAND guest_np_partner_tests)
+    if(WIN32)
+        set_tests_properties(guest_np_partner PROPERTIES ENVIRONMENT_MODIFICATION
+            "PATH=path_list_prepend:$<TARGET_FILE_DIR:libSceNpPartner001>")
+    endif()
+endif()
diff --git a/core/libs/prx/libSceNpPartner001/Export.cpp b/core/libs/prx/libSceNpPartner001/Export.cpp
index 74e81b2df..9d2e08977 100644
--- a/core/libs/prx/libSceNpPartner001/Export.cpp
+++ b/core/libs/prx/libSceNpPartner001/Export.cpp
@@ -1,14 +1,23 @@
 #include "prx/libc/include/General.hpp"
+#include <atomic>
+#include <stdexcept>
+#include <string>
+
+namespace {
+std::atomic<bool> g_initialized{false};
+}
 
 extern "C" {
 
 int APS5_VABI sceNpEAAccessInitialize(void) {
-    NotImplemented_nid_no_patch(__func__);
+    bool expected = false;
+    if (!g_initialized.compare_exchange_strong(expected, true)) throw std::logic_error(std::string(__func__) + ": already initialized");
     return 0;
 }
 
 int APS5_VABI sceNpEAAccessTerminate(void) {
-    NotImplemented_nid_no_patch(__func__);
+    bool expected = true;
+    if (!g_initialized.compare_exchange_strong(expected, false)) throw std::logic_error(std::string(__func__) + ": not initialized");
     return 0;
 }
 
diff --git a/core/libs/tests/GuestNpPartner.cpp b/core/libs/tests/GuestNpPartner.cpp
new file mode 100644
index 000000000..0121f30c8
--- /dev/null
+++ b/core/libs/tests/GuestNpPartner.cpp
@@ -0,0 +1,34 @@
+#include "prx/libc/include/general/VabiMacros.hpp"
+#include <cstdlib>
+#include <stdexcept>
+
+extern "C" {
+int APS5_VABI sceNpEAAccessInitialize(void);
+int APS5_VABI sceNpEAAccessTerminate(void);
+}
+
+namespace {
+
+void Require(bool value) { if (!value) std::abort(); }
+
+template <typename TAction>
+bool Throws(TAction action) {
+    try {
+        action();
+    } catch (const std::logic_error&) {
+        return true;
+    }
+    return false;
+}
+
+}
+
+int main() {
+    Require(Throws([] { sceNpEAAccessTerminate(); }));
+    Require(sceNpEAAccessInitialize() == 0);
+    Require(Throws([] { sceNpEAAccessInitialize(); }));
+    Require(sceNpEAAccessTerminate() == 0);
+    Require(Throws([] { sceNpEAAccessTerminate(); }));
+    Require(sceNpEAAccessInitialize() == 0);
+    Require(sceNpEAAccessTerminate() == 0);
+}
diff --git a/docs/dev/debt/libSceNpPartner001.md b/docs/dev/debt/libSceNpPartner001.md
index f032f97da..02e1a7ab4 100644
--- a/docs/dev/debt/libSceNpPartner001.md
+++ b/docs/dev/debt/libSceNpPartner001.md
@@ -3,3 +3,7 @@
 ### Unknown function info
 
 - [sceNpEAAccessInitialize, sceNpEAAccessTerminate](../../../core/libs/prx/libSceNpPartner001/Export.cpp) (libSceNpPartner001) - names and the no-argument signatures follow [shadPS4](https://github.com/shadps4-emu/shadPS4/blob/main/src/core/libraries/np/np_partner.cpp); imported by PPSA23566, not confirmed on a PS5 title
+
+### Functional
+
+- [sceNpEAAccessInitialize, sceNpEAAccessTerminate](../../../core/libs/prx/libSceNpPartner001/Export.cpp) (libSceNpPartner001) - initialization marks the library initialized without contacting the server and termination clears it, as in [shadPS4](https://github.com/shadps4-emu/shadPS4/blob/main/src/core/libraries/np/np_partner.cpp); whether the console fails initialization while signed out is unknown. Termination without initialization throws where shadPS4 returns the PS4 error `0x819D0001`, whose PS5 value is unverified, and a second initialization throws where shadPS4 returns 0 without checking. PPSA23566 imports both, not confirmed on its start-up path