From 897d9d4099a52c817bccc7245fa9d797bf2bd13f Mon Sep 17 00:00:00 2001
From: Aiken Harris <harraiken91@gmail.com>
Date: Sun, 10 May 2026 23:42:13 +0200
Subject: [PATCH] Expose timer performance counter and clock rate functions

---
 sdk/xtdk/hlfuncs.h     | 10 ++++++++++
 xtoskrnl/hl/exports.cc | 36 ++++++++++++++++++++++++++++++++++++
 xtoskrnl/xtoskrnl.spec |  2 ++
 3 files changed, 48 insertions(+)

diff --git a/sdk/xtdk/hlfuncs.h b/sdk/xtdk/hlfuncs.h
index 6bb6a5f..34dbc99 100644
--- a/sdk/xtdk/hlfuncs.h
+++ b/sdk/xtdk/hlfuncs.h
@@ -18,6 +18,11 @@
 #ifndef __XTOS_ASSEMBLER__
 
 /* Hardware layer routines forward references */
+XTCLINK
+XTAPI
+LARGE_INTEGER
+HlQueryPerformanceCounter(OUT PLARGE_INTEGER PerformanceFrequency);
+
 XTCLINK
 XTAPI
 UCHAR
@@ -33,6 +38,11 @@ XTAPI
 ULONG
 HlReadRegister32(IN PVOID Register);
 
+XTCLINK
+XTAPI
+ULONG
+HlSetClockRate(IN ULONG Rate);
+
 XTCLINK
 XTAPI
 VOID
diff --git a/xtoskrnl/hl/exports.cc b/xtoskrnl/hl/exports.cc
index 0321cf1..0832ea4 100644
--- a/xtoskrnl/hl/exports.cc
+++ b/xtoskrnl/hl/exports.cc
@@ -9,6 +9,24 @@
 #include <xtos.hh>
 
 
+/**
+ * Retrieves the current value of the high-resolution performance counter.
+ *
+ * @param PerformanceFrequency
+ *        Suplies an optional pointer to a variable that receives the performance counter frequency in Hz.
+ *
+ * @return This routine returns the current 64-bit monotonic tick count.
+ *
+ * @since XT 1.0
+ */
+XTCLINK
+XTAPI
+LARGE_INTEGER
+HlQueryPerformanceCounter(OUT PLARGE_INTEGER PerformanceFrequency)
+{
+    return HL::Timer::QueryPerformanceCounter(PerformanceFrequency);
+}
+
 /**
  * Reads the 8-bit data from the specified I/O port.
  *
@@ -117,6 +135,24 @@ HlReadRegister32(IN PVOID Register)
     return HL::IoRegister::ReadRegister32(Register);
 }
 
+/**
+ * Requests a dynamic adjustment of the system clock resolution.
+ *
+ * @param Rate
+ *        The requested clock rate change in 100-nanosecond units.
+ *
+ * @return This routine returns the actual clock rate granted by the hardware.
+ *
+ * @since XT 1.0
+ */
+XTCLINK
+XTAPI
+ULONG
+HlSetClockRate(IN ULONG Rate)
+{
+    return HL::Timer::SetClockRate(Rate);
+}
+
 /**
  * Writes the 8-bit data to the specified I/O port.
  *
diff --git a/xtoskrnl/xtoskrnl.spec b/xtoskrnl/xtoskrnl.spec
index 17d6fa1..f5d47ff 100644
--- a/xtoskrnl/xtoskrnl.spec
+++ b/xtoskrnl/xtoskrnl.spec
@@ -6,12 +6,14 @@
 @ fastcall ExReInitializeRundownProtection(ptr)
 @ fastcall ExReleaseRundownProtection(ptr)
 @ fastcall ExWaitForRundownProtectionRelease(ptr)
+@ stdcall HlQueryPerformanceCounter(ptr)
 @ cdecl HlReadPort8(ptr)
 @ cdecl HlReadPort16(ptr)
 @ cdecl HlReadPort32(ptr)
 @ stdcall HlReadRegister8(ptr)
 @ stdcall HlReadRegister16(ptr)
 @ stdcall HlReadRegister32(ptr)
+@ stdcall HlSetClockRate(long)
 @ cdecl HlWritePort8(ptr long)
 @ cdecl HlWritePort16(ptr long)
 @ cdecl HlWritePort32(ptr long)