13 files changed, 90 insertions, 80 deletions

diff --git a/src/common/arm64/native_clock.cpp b/src/common/arm64/native_clock.cpp
index f437d7187..76ffb74ba 100644
--- a/src/common/arm64/native_clock.cpp
+++ b/src/common/arm64/native_clock.cpp
@@ -30,27 +30,27 @@ NativeClock::NativeClock() {
 }
 
 std::chrono::nanoseconds NativeClock::GetTimeNS() const {
-    return std::chrono::nanoseconds{MultiplyHigh(GetHostTicksElapsed(), ns_cntfrq_factor)};
+    return std::chrono::nanoseconds{MultiplyHigh(GetUptime(), ns_cntfrq_factor)};
 }
 
 std::chrono::microseconds NativeClock::GetTimeUS() const {
-    return std::chrono::microseconds{MultiplyHigh(GetHostTicksElapsed(), us_cntfrq_factor)};
+    return std::chrono::microseconds{MultiplyHigh(GetUptime(), us_cntfrq_factor)};
 }
 
 std::chrono::milliseconds NativeClock::GetTimeMS() const {
-    return std::chrono::milliseconds{MultiplyHigh(GetHostTicksElapsed(), ms_cntfrq_factor)};
+    return std::chrono::milliseconds{MultiplyHigh(GetUptime(), ms_cntfrq_factor)};
 }
 
-u64 NativeClock::GetCNTPCT() const {
-    return MultiplyHigh(GetHostTicksElapsed(), guest_cntfrq_factor);
+s64 NativeClock::GetCNTPCT() const {
+    return MultiplyHigh(GetUptime(), guest_cntfrq_factor);
 }
 
-u64 NativeClock::GetGPUTick() const {
-    return MultiplyHigh(GetHostTicksElapsed(), gputick_cntfrq_factor);
+s64 NativeClock::GetGPUTick() const {
+    return MultiplyHigh(GetUptime(), gputick_cntfrq_factor);
 }
 
-u64 NativeClock::GetHostTicksNow() const {
-    u64 cntvct_el0 = 0;
+s64 NativeClock::GetUptime() const {
+    s64 cntvct_el0 = 0;
     asm volatile("dsb ish\n\t"
                  "mrs %[cntvct_el0], cntvct_el0\n\t"
                  "dsb ish\n\t"
@@ -58,15 +58,11 @@ u64 NativeClock::GetHostTicksNow() const {
     return cntvct_el0;
 }
 
-u64 NativeClock::GetHostTicksElapsed() const {
-    return GetHostTicksNow();
-}
-
 bool NativeClock::IsNative() const {
     return true;
 }
 
-u64 NativeClock::GetHostCNTFRQ() {
+s64 NativeClock::GetHostCNTFRQ() {
     u64 cntfrq_el0 = 0;
     std::string_view board{""};
 #ifdef ANDROID
diff --git a/src/common/arm64/native_clock.h b/src/common/arm64/native_clock.h
index a28b419f2..94bc1882e 100644
--- a/src/common/arm64/native_clock.h
+++ b/src/common/arm64/native_clock.h
@@ -17,17 +17,15 @@ public:
 
     std::chrono::milliseconds GetTimeMS() const override;
 
-    u64 GetCNTPCT() const override;
+    s64 GetCNTPCT() const override;
 
-    u64 GetGPUTick() const override;
+    s64 GetGPUTick() const override;
 
-    u64 GetHostTicksNow() const override;
-
-    u64 GetHostTicksElapsed() const override;
+    s64 GetUptime() const override;
 
     bool IsNative() const override;
 
-    static u64 GetHostCNTFRQ();
+    static s64 GetHostCNTFRQ();
 
 public:
     using FactorType = unsigned __int128;
diff --git a/src/common/common_types.h b/src/common/common_types.h
index 0fc225aff..ae04c4d60 100644
--- a/src/common/common_types.h
+++ b/src/common/common_types.h
@@ -45,6 +45,7 @@ using f32 = float;  ///< 32-bit floating point
 using f64 = double; ///< 64-bit floating point
 
 using VAddr = u64;    ///< Represents a pointer in the userspace virtual address space.
+using DAddr = u64;    ///< Represents a pointer in the device specific virtual address space.
 using PAddr = u64;    ///< Represents a pointer in the ARM11 physical address space.
 using GPUVAddr = u64; ///< Represents a pointer in the GPU virtual address space.
 
diff --git a/src/common/fs/file.h b/src/common/fs/file.h
index 167c4d826..2e2396075 100644
--- a/src/common/fs/file.h
+++ b/src/common/fs/file.h
@@ -37,7 +37,7 @@ void OpenFileStream(FileStream& file_stream, const std::filesystem::path& path,
 template <typename FileStream, typename Path>
 void OpenFileStream(FileStream& file_stream, const Path& path, std::ios_base::openmode open_mode) {
     if constexpr (IsChar<typename Path::value_type>) {
-        file_stream.open(ToU8String(path), open_mode);
+        file_stream.open(std::filesystem::path{ToU8String(path)}, open_mode);
     } else {
         file_stream.open(std::filesystem::path{path}, open_mode);
     }
diff --git a/src/common/memory_detect.h b/src/common/memory_detect.h
index a345e6d28..c8f239aed 100644
--- a/src/common/memory_detect.h
+++ b/src/common/memory_detect.h
@@ -18,4 +18,4 @@ struct MemoryInfo {
  */
 [[nodiscard]] const MemoryInfo& GetMemInfo();
 
-} // namespace Common
\ No newline at end of file
+} // namespace Common
diff --git a/src/common/overflow.h b/src/common/overflow.h
index 44d8e7e73..e184ead95 100644
--- a/src/common/overflow.h
+++ b/src/common/overflow.h
@@ -3,6 +3,7 @@
 
 #pragma once
 
+#include <algorithm>
 #include <type_traits>
 #include "bit_cast.h"
 
@@ -19,4 +20,21 @@ inline T WrappingAdd(T lhs, T rhs) {
     return BitCast<T>(lhs_u + rhs_u);
 }
 
+template <typename T>
+    requires(std::is_integral_v<T> && std::is_signed_v<T>)
+inline bool CanAddWithoutOverflow(T lhs, T rhs) {
+#ifdef _MSC_VER
+    if (lhs >= 0 && rhs >= 0) {
+        return WrappingAdd(lhs, rhs) >= std::max(lhs, rhs);
+    } else if (lhs < 0 && rhs < 0) {
+        return WrappingAdd(lhs, rhs) <= std::min(lhs, rhs);
+    } else {
+        return true;
+    }
+#else
+    T res;
+    return !__builtin_add_overflow(lhs, rhs, &res);
+#endif
+}
+
 } // namespace Common
diff --git a/src/common/settings.h b/src/common/settings.h
index 07dba53ab..16749ab68 100644
--- a/src/common/settings.h
+++ b/src/common/settings.h
@@ -419,9 +419,16 @@ struct Values {
         linkage, false, "custom_rtc_enabled", Category::System, Specialization::Paired, true, true};
     SwitchableSetting<s64> custom_rtc{
         linkage, 0,    "custom_rtc",       Category::System, Specialization::Time,
-        true,    true, &custom_rtc_enabled};
-    // Set on game boot, reset on stop. Seconds difference between current time and `custom_rtc`
-    s64 custom_rtc_differential;
+        false,   true, &custom_rtc_enabled};
+    SwitchableSetting<s64, true> custom_rtc_offset{linkage,
+                                                   0,
+                                                   std::numeric_limits<int>::min(),
+                                                   std::numeric_limits<int>::max(),
+                                                   "custom_rtc_offset",
+                                                   Category::System,
+                                                   Specialization::Countable,
+                                                   true,
+                                                   true};
     SwitchableSetting<bool> rng_seed_enabled{
         linkage, false, "rng_seed_enabled", Category::System, Specialization::Paired, true, true};
     SwitchableSetting<u32> rng_seed{
diff --git a/src/common/time_zone.cpp b/src/common/time_zone.cpp
index 69e728a9d..f77df604f 100644
--- a/src/common/time_zone.cpp
+++ b/src/common/time_zone.cpp
@@ -88,7 +88,17 @@ std::string FindSystemTimeZone() {
             LOG_ERROR(Common, "Time zone {} not handled, defaulting to hour offset.", tz_index);
         }
     }
-    return fmt::format("Etc/GMT{:s}{:d}", hours > 0 ? "-" : "+", std::abs(hours));
+
+    // For some reason the Etc/GMT times are reversed. GMT+6 contains -21600 as its offset,
+    // -6 hours instead of +6 hours, so these signs are purposefully reversed to fix it.
+    std::string postfix{""};
+    if (hours > 0) {
+        postfix = fmt::format("-{:d}", std::abs(hours));
+    } else if (hours < 0) {
+        postfix = fmt::format("+{:d}", std::abs(hours));
+    }
+
+    return fmt::format("Etc/GMT{:s}", postfix);
 }
 
 } // namespace Common::TimeZone
diff --git a/src/common/uuid.h b/src/common/uuid.h
index 7172ca165..81bfefbbb 100644
--- a/src/common/uuid.h
+++ b/src/common/uuid.h
@@ -12,9 +12,8 @@
 namespace Common {
 
 struct UUID {
-    std::array<u8, 0x10> uuid{};
+    std::array<u8, 0x10> uuid;
 
-    /// Constructs an invalid UUID.
     constexpr UUID() = default;
 
     /// Constructs a UUID from a reference to a 128 bit array.
@@ -34,14 +33,6 @@ struct UUID {
      */
     explicit UUID(std::string_view uuid_string);
 
-    ~UUID() = default;
-
-    constexpr UUID(const UUID&) noexcept = default;
-    constexpr UUID(UUID&&) noexcept = default;
-
-    constexpr UUID& operator=(const UUID&) noexcept = default;
-    constexpr UUID& operator=(UUID&&) noexcept = default;
-
     /**
      * Returns whether the stored UUID is valid or not.
      *
@@ -121,6 +112,7 @@ struct UUID {
     friend constexpr bool operator==(const UUID& lhs, const UUID& rhs) = default;
 };
 static_assert(sizeof(UUID) == 0x10, "UUID has incorrect size.");
+static_assert(std::is_trivial_v<UUID>);
 
 /// An invalid UUID. This UUID has all its bytes set to 0.
 constexpr UUID InvalidUUID = {};
diff --git a/src/common/wall_clock.cpp b/src/common/wall_clock.cpp
index 012fdc1e0..e14bf3e65 100644
--- a/src/common/wall_clock.cpp
+++ b/src/common/wall_clock.cpp
@@ -18,42 +18,40 @@ namespace Common {
 
 class StandardWallClock final : public WallClock {
 public:
-    explicit StandardWallClock() : start_time{SteadyClock::Now()} {}
+    explicit StandardWallClock() {}
 
     std::chrono::nanoseconds GetTimeNS() const override {
-        return SteadyClock::Now() - start_time;
+        return std::chrono::duration_cast<std::chrono::nanoseconds>(
+            std::chrono::system_clock::now().time_since_epoch());
     }
 
     std::chrono::microseconds GetTimeUS() const override {
-        return static_cast<std::chrono::microseconds>(GetHostTicksElapsed() / NsToUsRatio::den);
+        return std::chrono::duration_cast<std::chrono::microseconds>(
+            std::chrono::system_clock::now().time_since_epoch());
     }
 
     std::chrono::milliseconds GetTimeMS() const override {
-        return static_cast<std::chrono::milliseconds>(GetHostTicksElapsed() / NsToMsRatio::den);
+        return std::chrono::duration_cast<std::chrono::milliseconds>(
+            std::chrono::system_clock::now().time_since_epoch());
     }
 
-    u64 GetCNTPCT() const override {
-        return GetHostTicksElapsed() * NsToCNTPCTRatio::num / NsToCNTPCTRatio::den;
+    s64 GetCNTPCT() const override {
+        return GetUptime() * NsToCNTPCTRatio::num / NsToCNTPCTRatio::den;
     }
 
-    u64 GetGPUTick() const override {
-        return GetHostTicksElapsed() * NsToGPUTickRatio::num / NsToGPUTickRatio::den;
+    s64 GetGPUTick() const override {
+        return GetUptime() * NsToGPUTickRatio::num / NsToGPUTickRatio::den;
     }
 
-    u64 GetHostTicksNow() const override {
-        return static_cast<u64>(SteadyClock::Now().time_since_epoch().count());
-    }
-
-    u64 GetHostTicksElapsed() const override {
-        return static_cast<u64>(GetTimeNS().count());
+    s64 GetUptime() const override {
+        return std::chrono::duration_cast<std::chrono::nanoseconds>(
+                   std::chrono::steady_clock::now().time_since_epoch())
+            .count();
     }
 
     bool IsNative() const override {
         return false;
     }
-
-private:
-    SteadyClock::time_point start_time;
 };
 
 std::unique_ptr<WallClock> CreateOptimalClock() {
diff --git a/src/common/wall_clock.h b/src/common/wall_clock.h
index f45d3d8c5..3a0c43909 100644
--- a/src/common/wall_clock.h
+++ b/src/common/wall_clock.h
@@ -29,16 +29,13 @@ public:
     virtual std::chrono::milliseconds GetTimeMS() const = 0;
 
     /// @returns The guest CNTPCT ticks since the construction of this clock.
-    virtual u64 GetCNTPCT() const = 0;
+    virtual s64 GetCNTPCT() const = 0;
 
     /// @returns The guest GPU ticks since the construction of this clock.
-    virtual u64 GetGPUTick() const = 0;
+    virtual s64 GetGPUTick() const = 0;
 
     /// @returns The raw host timer ticks since an indeterminate epoch.
-    virtual u64 GetHostTicksNow() const = 0;
-
-    /// @returns The raw host timer ticks since the construction of this clock.
-    virtual u64 GetHostTicksElapsed() const = 0;
+    virtual s64 GetUptime() const = 0;
 
     /// @returns Whether the clock directly uses the host's hardware clock.
     virtual bool IsNative() const = 0;
diff --git a/src/common/x64/native_clock.cpp b/src/common/x64/native_clock.cpp
index 7d2a26bd9..d2d27fafe 100644
--- a/src/common/x64/native_clock.cpp
+++ b/src/common/x64/native_clock.cpp
@@ -8,39 +8,35 @@
 namespace Common::X64 {
 
 NativeClock::NativeClock(u64 rdtsc_frequency_)
-    : start_ticks{FencedRDTSC()}, rdtsc_frequency{rdtsc_frequency_},
-      ns_rdtsc_factor{GetFixedPoint64Factor(NsRatio::den, rdtsc_frequency)},
+    : rdtsc_frequency{rdtsc_frequency_}, ns_rdtsc_factor{GetFixedPoint64Factor(NsRatio::den,
+                                                                               rdtsc_frequency)},
       us_rdtsc_factor{GetFixedPoint64Factor(UsRatio::den, rdtsc_frequency)},
       ms_rdtsc_factor{GetFixedPoint64Factor(MsRatio::den, rdtsc_frequency)},
       cntpct_rdtsc_factor{GetFixedPoint64Factor(CNTFRQ, rdtsc_frequency)},
       gputick_rdtsc_factor{GetFixedPoint64Factor(GPUTickFreq, rdtsc_frequency)} {}
 
 std::chrono::nanoseconds NativeClock::GetTimeNS() const {
-    return std::chrono::nanoseconds{MultiplyHigh(GetHostTicksElapsed(), ns_rdtsc_factor)};
+    return std::chrono::nanoseconds{MultiplyHigh(GetUptime(), ns_rdtsc_factor)};
 }
 
 std::chrono::microseconds NativeClock::GetTimeUS() const {
-    return std::chrono::microseconds{MultiplyHigh(GetHostTicksElapsed(), us_rdtsc_factor)};
+    return std::chrono::microseconds{MultiplyHigh(GetUptime(), us_rdtsc_factor)};
 }
 
 std::chrono::milliseconds NativeClock::GetTimeMS() const {
-    return std::chrono::milliseconds{MultiplyHigh(GetHostTicksElapsed(), ms_rdtsc_factor)};
+    return std::chrono::milliseconds{MultiplyHigh(GetUptime(), ms_rdtsc_factor)};
 }
 
-u64 NativeClock::GetCNTPCT() const {
-    return MultiplyHigh(GetHostTicksElapsed(), cntpct_rdtsc_factor);
+s64 NativeClock::GetCNTPCT() const {
+    return MultiplyHigh(GetUptime(), cntpct_rdtsc_factor);
 }
 
-u64 NativeClock::GetGPUTick() const {
-    return MultiplyHigh(GetHostTicksElapsed(), gputick_rdtsc_factor);
+s64 NativeClock::GetGPUTick() const {
+    return MultiplyHigh(GetUptime(), gputick_rdtsc_factor);
 }
 
-u64 NativeClock::GetHostTicksNow() const {
-    return FencedRDTSC();
-}
-
-u64 NativeClock::GetHostTicksElapsed() const {
-    return FencedRDTSC() - start_ticks;
+s64 NativeClock::GetUptime() const {
+    return static_cast<s64>(FencedRDTSC());
 }
 
 bool NativeClock::IsNative() const {
diff --git a/src/common/x64/native_clock.h b/src/common/x64/native_clock.h
index 334415eff..b2629b031 100644
--- a/src/common/x64/native_clock.h
+++ b/src/common/x64/native_clock.h
@@ -17,18 +17,15 @@ public:
 
     std::chrono::milliseconds GetTimeMS() const override;
 
-    u64 GetCNTPCT() const override;
+    s64 GetCNTPCT() const override;
 
-    u64 GetGPUTick() const override;
+    s64 GetGPUTick() const override;
 
-    u64 GetHostTicksNow() const override;
-
-    u64 GetHostTicksElapsed() const override;
+    s64 GetUptime() const override;
 
     bool IsNative() const override;
 
 private:
-    u64 start_ticks;
     u64 rdtsc_frequency;
 
     u64 ns_rdtsc_factor;