diff --git a/rts/System/Platform/CpuTopologyGeneric.cpp b/rts/System/Platform/CpuTopologyGeneric.cpp
new file mode 100644
index 00000000000..cfad9fe7faa
--- /dev/null
+++ b/rts/System/Platform/CpuTopologyGeneric.cpp
@@ -0,0 +1,45 @@
+/* This file is part of the Recoil engine (GPL v2 or later), see LICENSE.html */
+
+// Generic, platform-agnostic cpu_topology implementation for tool builds
+// (e.g. unitsync) that link the thread pool for parallel work but never pin
+// threads. It reports every logical core as a single group of performance
+// cores with no P/E split, no SMT/hyper-threading distinction and no cache
+// grouping, and requests no thread pinning. This satisfies the three
+// cpu_topology symbols pulled in by CpuID/Threading without dragging in the
+// real per-platform topology detection (Platform/{Linux,Win,Mac}/CpuTopology.cpp).
+//
+// The engine and dedicated server do NOT use this; they link the real
+// per-platform implementation for sim-worker pinning.
+
+#include "CpuTopology.h"
+
+#include <algorithm>
+#include <thread>
+
+namespace cpu_topology {
+
+ThreadPinPolicy GetThreadPinPolicy() {
+	return THREAD_PIN_POLICY_NONE;
+}
+
+ProcessorMasks GetProcessorMasks() {
+	ProcessorMasks processorMasks;
+
+	// Masks are 32 bits wide; cap to match the real per-platform implementations
+	// (MAX_CPUS == 32). Treat every logical core as a performance core so that
+	// CPUID::EnumerateCores() derives a correct logical-core count for the pool.
+	const unsigned int logicalCores = std::min(32u, std::thread::hardware_concurrency());
+
+	processorMasks.performanceCoreMask =
+		(logicalCores >= 32u) ? ~0u : ((1u << logicalCores) - 1u);
+
+	return processorMasks;
+}
+
+ProcessorCaches GetProcessorCache() {
+	// No cache grouping: the only consumers (the affinity/pinning helpers in
+	// Threading.cpp) are never reached on the tool path.
+	return ProcessorCaches{};
+}
+
+} // namespace cpu_topology
diff --git a/tools/unitsync/CMakeLists.txt b/tools/unitsync/CMakeLists.txt
index 00f124f0a78..db456d8d365 100644
--- a/tools/unitsync/CMakeLists.txt
+++ b/tools/unitsync/CMakeLists.txt
@@ -82,6 +82,10 @@ set(main_files
 	"${ENGINE_SRC_ROOT}/System/Misc/SpringTime.cpp"
 	"${ENGINE_SRC_ROOT}/System/Platform/CpuID.cpp"
 	"${ENGINE_SRC_ROOT}/System/Platform/CpuTopologyCommon.cpp"
+	## unitsync needs the thread pool (for parallel archive scanning) but never
+	## pins threads, so it links a generic cpu_topology instead of the real
+	## per-platform Platform/{Linux,Win,Mac}/CpuTopology.cpp detection.
+	"${ENGINE_SRC_ROOT}/System/Platform/CpuTopologyGeneric.cpp"
 	"${ENGINE_SRC_ROOT}/System/Platform/Misc.cpp"
 	"${ENGINE_SRC_ROOT}/System/Platform/ScopedFileLock.cpp"
 	"${ENGINE_SRC_ROOT}/System/Platform/Threading.cpp"
@@ -102,20 +106,24 @@ set(main_files
 	"${ENGINE_SRC_ROOT}/System/StringUtil.cpp"
 	)
 if (WIN32)
-	list(APPEND main_files "${ENGINE_SRC_ROOT}/System/Platform/Win/CpuTopology.cpp")
 	list(APPEND main_files "${ENGINE_SRC_ROOT}/System/Platform/Win/Hardware.cpp")
 	list(APPEND main_files "${ENGINE_SRC_ROOT}/System/Platform/Win/WinVersion.cpp")
 	list(APPEND main_files "${ENGINE_SRC_ROOT}/System/Platform/SharedLib.cpp")
 	list(APPEND main_files "${ENGINE_SRC_ROOT}/System/Platform/Win/DllLib.cpp")
 else (WIN32)
-	list(APPEND main_files "${ENGINE_SRC_ROOT}/System/Platform/Linux/CpuTopology.cpp")
 	list(APPEND main_files "${ENGINE_SRC_ROOT}/System/Platform/Linux/Hardware.cpp")
 	list(APPEND main_files "${ENGINE_SRC_ROOT}/System/Platform/Linux/ThreadSupport.cpp")
 endif (WIN32)
 
+# The shared engine threading source list pulls in the real per-platform
+# Platform/{Linux,Win,Mac}/CpuTopology.cpp. unitsync links a generic
+# cpu_topology instead (see main_files above), so strip the platform file here.
+set(unitsync_threading_files ${sources_engine_System_Threading})
+list(FILTER unitsync_threading_files EXCLUDE REGEX "Platform/(Linux|Win|Mac)/CpuTopology\\.cpp$")
+
 set(unitsync_files
 	${sources_engine_System_FileSystem}
-	${sources_engine_System_Threading}
+	${unitsync_threading_files}
 	${sources_engine_System_Log}
 	${sources_engine_System_Log_sinkFile}
 	${sources_engine_System_Log_sinkOutputDebugString}