1 files changed, 139 insertions, 0 deletions
diff --git a/packages/ptc/src/dos/timeunit/timeunit.pp b/packages/ptc/src/dos/timeunit/timeunit.pp
new file mode 100644
index 0000000000..17dd5419b4
--- /dev/null
+++ b/packages/ptc/src/dos/timeunit/timeunit.pp
@@ -0,0 +1,139 @@
+{$MODE objfpc}
+{$ASMMODE intel}
+{$goto on}
+
+Unit timeunit;
+
+Interface
+
+Type
+  TGetClockTics = Function : QWord;
+
+Var
+  TimerResolution : Double;
+  CPS : Double;
+  GetClockTics : TGetClockTics;
+
+Implementation
+
+Var
+  UseRDTSC : Boolean;
+  Clk1Lo, Clk1Hi, Clk2Lo, Clk2Hi : DWord;
+  Clk1, Clk2 : QWord;
+  ClkDelta : QWord;
+  CpuFlags : DWord;
+
+Function GetClockTics_RDTSC : QWord; Assembler;
+
+Asm
+  rdtsc
+End;
+
+Function GetClockTics_LAME : QWord;
+
+Begin
+  GetClockTics_LAME := MemL[$46C];
+End;
+
+Procedure DetectCPUSpeed_RDTSC;
+
+Begin
+  {word absolute $46C}
+  Asm
+    mov di, fs:[046Ch]
+@@1:
+    cmp di, fs:[046Ch]
+    je @@1
+    rdtsc
+    mov ebx, eax
+    mov ecx, edx
+    mov di, fs:[046Ch]
+@@2:
+    mov ax, fs:[046Ch]
+    sub ax, di
+    cmp ax, 32
+    jb @@2
+    rdtsc
+    mov [Clk1Lo], ebx
+    mov [Clk1Hi], ecx
+    mov [Clk2Lo], eax
+    mov [Clk2Hi], edx
+  End ['EAX','EBX','ECX','EDX','EDI'];
+{  Clk1 := Clk1Lo Or (QWord(Clk1Hi) Shl 32);
+  Clk2 := Clk2Lo Or (QWord(Clk2Hi) Shl 32);}
+  Clk1 := Clk1Hi;
+  Clk1 := Clk1 Shl 32;
+  Clk1 := Clk1 + Clk1Lo;
+  Clk2 := Clk2Hi;
+  Clk2 := Clk2 Shl 32;
+  Clk2 := Clk2 + Clk2Lo;
+  ClkDelta := Clk2 - Clk1;
+  CPS := (ClkDelta * 18.2) / 32;
+  TimerResolution := 1 / CPS;
+End;
+
+Procedure _CPU; Assembler;
+
+Label
+  nocpuid;
+
+Asm
+  mov CpuFlags, 0
+  pushf
+  pop eax
+  mov ecx, eax
+  xor eax, 40000h
+  push eax
+  popf
+  pushf
+  pop eax
+  xor eax, ecx
+  jz nocpuid
+  push ecx
+  popf
+  mov eax, ecx
+  xor eax, 200000h
+  push eax
+  popf
+  pushf
+  pop eax
+  xor eax, ecx
+  je nocpuid
+
+  pusha
+  mov eax, 1
+  cpuid
+  mov CpuFlags, edx
+  popa
+
+nocpuid:
+End;
+
+Procedure DetectCPU;
+
+Begin
+  _CPU;
+  If (CpuFlags And $10) <> 0 Then
+    UseRDTSC := True
+  Else
+    UseRDTSC := False;
+
+  If UseRDTSC Then
+  Begin
+    DetectCPUSpeed_RDTSC;
+    GetClockTics := @GetClockTics_RDTSC;
+  End
+  Else
+  Begin
+    TimerResolution := 1 / 18.2;
+    GetClockTics := @GetClockTics_LAME;
+  End;
+End;
+
+Initialization
+
+Begin
+  DetectCPU;
+End;
+
+End.