hle: kernel: KSystemControl does not belong in Memory namespace.

1 files changed, 42 insertions, 0 deletions

diff --git a/src/core/hle/kernel/k_system_control.cpp b/src/core/hle/kernel/k_system_control.cpp
new file mode 100644
index 000000000..aa1682f69
--- /dev/null
+++ b/src/core/hle/kernel/k_system_control.cpp
@@ -0,0 +1,42 @@
+// Copyright 2021 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <random>
+
+#include "core/hle/kernel/k_system_control.h"
+
+namespace Kernel {
+
+namespace {
+template <typename F>
+u64 GenerateUniformRange(u64 min, u64 max, F f) {
+    // Handle the case where the difference is too large to represent.
+    if (max == std::numeric_limits<u64>::max() && min == std::numeric_limits<u64>::min()) {
+        return f();
+    }
+
+    // Iterate until we get a value in range.
+    const u64 range_size = ((max + 1) - min);
+    const u64 effective_max = (std::numeric_limits<u64>::max() / range_size) * range_size;
+    while (true) {
+        if (const u64 rnd = f(); rnd < effective_max) {
+            return min + (rnd % range_size);
+        }
+    }
+}
+
+} // Anonymous namespace
+
+u64 KSystemControl::GenerateRandomU64() {
+    static std::random_device device;
+    static std::mt19937 gen(device());
+    static std::uniform_int_distribution<u64> distribution(1, std::numeric_limits<u64>::max());
+    return distribution(gen);
+}
+
+u64 KSystemControl::GenerateRandomRange(u64 min, u64 max) {
+    return GenerateUniformRange(min, max, GenerateRandomU64);
+}
+
+} // namespace Kernel