diff --git a/rtl/x86_jit.pas b/rtl/x86_jit.pas
index d09c153c..33001683 100644
--- a/rtl/x86_jit.pas
+++ b/rtl/x86_jit.pas
@@ -14,12 +14,15 @@ uses
  x86_fpdbgdisas;
 
 type
+ t_jit_flags=Set Of (sES,sCS,sSS,sDS,sFS,sGS,sLOCK);
+
  t_jit_lea=packed object
   ARegValue:TRegValues;
   AOffset  :Int64;
   AMemSize :TOperandSize;
-  ASegment :Byte;
-  ALock    :Boolean;
+  AFlags   :t_jit_flags;
+  function ASegment:t_jit_flags; inline;
+  function ALock:Boolean; inline;
  end;
 
  t_vw_mode=(vwZero,vwOne,vwR64,vwM64);
@@ -63,7 +66,7 @@ type
   procedure EmitWord(w:Word); inline;
   procedure EmitInt32(i:Integer); inline;
   procedure EmitInt64(i:Int64); inline;
-  procedure EmitSelector(Segment:ShortInt); inline;
+  procedure EmitSelector(Segments:t_jit_flags); inline;
   procedure EmitREX(rexB,rexX,rexR,rexW:Boolean); inline;
   procedure EmitModRM(Mode,Index,RM:Byte); inline;
   procedure EmitSIB(Scale,Index,Base:Byte); inline;
@@ -161,9 +164,9 @@ type
  p_jit_builder=^t_jit_builder;
  t_jit_builder=object
   Const
-   LOCK:t_jit_lea=(ARegValue:((AType:regNone),(AType:regNone));ALock:True);
-   FS  :t_jit_lea=(ARegValue:((AType:regNone),(AType:regNone));ASegment:4);
-   GS  :t_jit_lea=(ARegValue:((AType:regNone),(AType:regNone));ASegment:5);
+   LOCK:t_jit_lea=(AFlags:[sLOCK]);
+   FS  :t_jit_lea=(AFlags:[sFS]);
+   GS  :t_jit_lea=(AFlags:[sGS]);
 
    ah  :TRegValue=(AType:regGeneralH;ASize:os8;AIndex:0);
    ch  :TRegValue=(AType:regGeneralH;ASize:os8;AIndex:1);
@@ -474,6 +477,18 @@ function classif_offset_se64(AOffset:Int64):TOperandSize;
 
 implementation
 
+function t_jit_lea.ASegment:t_jit_flags; inline;
+begin
+ Result:=AFlags-[sLOCK];
+end;
+
+function t_jit_lea.ALock:Boolean; inline;
+begin
+ Result:=sLOCK in AFlags;
+end;
+
+///
+
 function t_jit_data.c(n1,n2:p_jit_data):Integer;
 begin
  Result:=Integer(n1^.pData>n2^.pData)-Integer(n1^.pData<n2^.pData);
@@ -593,15 +608,6 @@ begin
          ((reg.ARegValue[1].AType in AType) or (reg.ARegValue[1].AType=regNone));
 end;
 
-function is_valid_seg(reg:t_jit_lea):Boolean; inline;
-begin
- case reg.ASegment of
-  0..5:Result:=True
-  else
-       Result:=False;
- end;
-end;
-
 function is_valid_scale(reg:t_jit_lea):Boolean; inline;
 begin
  Result:=is_valid_scale(reg.ARegValue[0]) and (reg.ARegValue[1].AScale<=1)
@@ -638,18 +644,6 @@ begin
   Result.ARegValue[0]:=B.ARegValue[0];
  end;
 
- if is_valid_seg(Result) then
- begin
-  if is_valid_seg(B) then
-  begin
-   Result.ASegment:=B.ASegment;
-  end;
- end else
- if is_valid_seg(B) then
- begin
-  Result.ASegment:=B.ASegment;
- end;
-
  if (Result.AMemSize<>os0) then
  begin
   if (B.AMemSize<>os0) then
@@ -662,7 +656,7 @@ begin
   Result.AMemSize:=B.AMemSize;
  end;
 
- Result.ALock:=Result.ALock or B.ALock;
+ Result.AFlags:=Result.AFlags+B.AFlags;
 
  Result.AOffset:=Result.AOffset+B.AOffset;
 end;
@@ -1011,13 +1005,14 @@ begin
  Inc(ASize,SizeOf(Int64));
 end;
 
-procedure t_jit_instruction.EmitSelector(Segment:ShortInt); inline;
+procedure t_jit_instruction.EmitSelector(Segments:t_jit_flags); inline;
 begin
- case Segment of //Selector
-  4:EmitByte($64); //fs
-  5:EmitByte($65); //gs
-  else;
- end;
+ if (sES in Segments) then EmitByte($26);
+ if (sCS in Segments) then EmitByte($2E);
+ if (sSS in Segments) then EmitByte($36);
+ if (sDS in Segments) then EmitByte($3E);
+ if (sFS in Segments) then EmitByte($64);
+ if (sGS in Segments) then EmitByte($65);
 end;
 
 procedure t_jit_instruction.EmitREX(rexB,rexX,rexR,rexW:Boolean); inline;
diff --git a/sys/jit/kern_jit.pas b/sys/jit/kern_jit.pas
index 9232f13d..a3ab66e7 100644
--- a/sys/jit/kern_jit.pas
+++ b/sys/jit/kern_jit.pas
@@ -1094,6 +1094,53 @@ begin
  end;
 end;
 
+//rdi -> addr
+//rsi -> rdi
+//rdx -> rsi
+//rcx -> rdx
+//r8  -> rcx
+//r9  -> r8
+
+procedure ExecuteGuest; SysV_ABI_CDecl; assembler; nostackframe; public;
+asm
+ //save r13
+ movq %r13,%gs:teb.jitcall
+
+ //load curkthread,jit_ctx
+ movq %gs:teb.thread,%r13
+ leaq jit_frame_offset(%r13),%r13
+
+ //load r14,r15
+ movq %r14,jit_frame.tf_r14(%r13)
+ movq %r15,jit_frame.tf_r15(%r13)
+
+ //load r13
+ movq %gs:teb.jitcall,%r14
+ movq %r14,jit_frame.tf_r13(%r13)
+
+ //alloc rbp,rsp
+
+ //load addr
+ movq %rdi,%r14
+
+ //move params
+ movq %rsi,%rdi
+ movq %rdx,%rsi
+ movq %rcx,%rdx
+ movq %r8 ,%rcx
+ movq %r9 ,%r8
+
+ //call
+ call %r14
+
+ //restore rbp,rsp
+
+ //load r14,r15,r13
+ movq jit_frame.tf_r14(%r13),%r14
+ movq jit_frame.tf_r15(%r13),%r15
+ movq jit_frame.tf_r13(%r13),%r13
+end;
+
 procedure op_native2jit(var ctx:t_jit_context2;pcb,switch_stack:Boolean);
 begin
  with ctx.builder do