/*

   Version: MPL 1.1/GPL 2.0/LGPL 2.1

   The contents of this file are subject to the Mozilla Public License Version

   1.1 (the "License"); you may not use this file except in compliance with

   the License. You may obtain a copy of the License at

   http://www.mozilla.org/MPL/

   Software distributed under the License is distributed on an "AS IS" basis,

   WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License

   for the specific language governing rights and limitations under the License.

   The Original Code is the Open Hardware Monitor code.

   The Initial Developer of the Original Code is 

   Michael Möller <m.moeller@gmx.ch>.

   Portions created by the Initial Developer are Copyright (C) 2010

   the Initial Developer. All Rights Reserved.

   Contributor(s):

   Alternatively, the contents of this file may be used under the terms of

   either the GNU General Public License Version 2 or later (the "GPL"), or

   the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),

   in which case the provisions of the GPL or the LGPL are applicable instead

   of those above. If you wish to allow use of your version of this file only

   under the terms of either the GPL or the LGPL, and not to allow others to

   use your version of this file under the terms of the MPL, indicate your

   decision by deleting the provisions above and replace them with the notice

   and other provisions required by the GPL or the LGPL. If you do not delete

   the provisions above, a recipient may use your version of this file under

   the terms of any one of the MPL, the GPL or the LGPL.

 */

 using System;

 using System.Runtime.InteropServices;

 using Mono.Unix.Native;

 namespace OpenHardwareMonitor.Hardware {

   internal static class Opcode {

     private static IntPtr codeBuffer;

     private static ulong size;

     public static void Open() {  

       int p = (int)Environment.OSVersion.Platform;

       byte[] rdtscCode;

       byte[] cpuidCode;

       if (IntPtr.Size == 4) {

         rdtscCode = RDTSC_32;

         cpuidCode = CPUID_32;

       } else {

         rdtscCode = RDTSC_64;

         if ((p == 4) || (p == 128)) { // Unix

           cpuidCode = CPUID_64_LINUX;

         } else { // Windows

           cpuidCode = CPUID_64_WINDOWS;

         }

       }

       size = (ulong)(rdtscCode.Length + cpuidCode.Length);

       if ((p == 4) || (p == 128)) { // Unix

         codeBuffer = Syscall.mmap(IntPtr.Zero, size, 

           MmapProts.PROT_READ | MmapProts.PROT_WRITE | MmapProts.PROT_EXEC, 

           MmapFlags.MAP_ANONYMOUS | MmapFlags.MAP_PRIVATE, -1, 0);

       } else { // Windows

         codeBuffer = NativeMethods.VirtualAlloc(IntPtr.Zero,

           (UIntPtr)size, AllocationType.COMMIT | AllocationType.RESERVE, 

           MemoryProtection.EXECUTE_READWRITE);

       }

       Marshal.Copy(rdtscCode, 0, codeBuffer, rdtscCode.Length);

       Rdtsc = Marshal.GetDelegateForFunctionPointer(

         codeBuffer, typeof(RdtscDelegate)) as RdtscDelegate;

       IntPtr cpuidAddress = (IntPtr)((long)codeBuffer + rdtscCode.Length);

       Marshal.Copy(cpuidCode, 0, cpuidAddress, cpuidCode.Length);

       Cpuid = Marshal.GetDelegateForFunctionPointer(

         cpuidAddress, typeof(CpuidDelegate)) as CpuidDelegate;         

     }

     public static void Close() {

       Rdtsc = null;

       Cpuid = null;

       int p = (int)Environment.OSVersion.Platform;

       if ((p == 4) || (p == 128)) { // Unix

         Syscall.munmap(codeBuffer, size);

       } else { // Windows

         NativeMethods.VirtualFree(codeBuffer, UIntPtr.Zero, 

           FreeType.RELEASE);        

       }

     }

     [UnmanagedFunctionPointer(CallingConvention.StdCall)]

     public delegate ulong RdtscDelegate();

     public static RdtscDelegate Rdtsc;

     // unsigned __int64 __stdcall rdtsc() {

     //   return __rdtsc();

     // }

     private static readonly byte[] RDTSC_32 = new byte[] {

       0x0F, 0x31,                     // rdtsc   

       0xC3                            // ret  

     };

     private static readonly byte[] RDTSC_64 = new byte[] {

       0x0F, 0x31,                     // rdtsc  

       0x48, 0xC1, 0xE2, 0x20,         // shl rdx, 20h  

       0x48, 0x0B, 0xC2,               // or rax, rdx  

       0xC3                            // ret  

     };

     [UnmanagedFunctionPointer(CallingConvention.StdCall)]

     public delegate bool CpuidDelegate(uint index, uint ecxValue,

       out uint eax, out uint ebx, out uint ecx, out uint edx);

     public static CpuidDelegate Cpuid;

     // void __stdcall cpuidex(unsigned int index, unsigned int ecxValue, 

     //   unsigned int* eax, unsigned int* ebx, unsigned int* ecx, 

     //   unsigned int* edx)

     // {

     //   int info[4];	

     //   __cpuidex(info, index, ecxValue);

     //   *eax = info[0];

     //   *ebx = info[1];

     //   *ecx = info[2];

     //   *edx = info[3];

     // }

     private static readonly byte[] CPUID_32 = new byte[] {

       0x55,                           // push ebp  

       0x8B, 0xEC,                     // mov ebp, esp  

       0x83, 0xEC, 0x10,               // sub esp, 10h  

       0x8B, 0x45, 0x08,               // mov eax, dword ptr [ebp+8]  

       0x8B, 0x4D, 0x0C,               // mov ecx, dword ptr [ebp+0Ch]  

       0x53,                           // push ebx  

       0x0F, 0xA2,                     // cpuid  

       0x56,                           // push esi  

       0x8D, 0x75, 0xF0,               // lea esi, [info]  

       0x89, 0x06,                     // mov dword ptr [esi],eax  

       0x8B, 0x45, 0x10,               // mov eax, dword ptr [eax]  

       0x89, 0x5E, 0x04,               // mov dword ptr [esi+4], ebx  

       0x89, 0x4E, 0x08,               // mov dword ptr [esi+8], ecx  

       0x89, 0x56, 0x0C,               // mov dword ptr [esi+0Ch], edx  

       0x8B, 0x4D, 0xF0,               // mov ecx, dword ptr [info]  

       0x89, 0x08,                     // mov dword ptr [eax], ecx  

       0x8B, 0x45, 0x14,               // mov eax, dword ptr [ebx]  

       0x8B, 0x4D, 0xF4,               // mov ecx, dword ptr [ebp-0Ch]  

       0x89, 0x08,                     // mov dword ptr [eax], ecx  

       0x8B, 0x45, 0x18,               // mov eax, dword ptr [ecx]  

       0x8B, 0x4D, 0xF8,               // mov ecx, dword ptr [ebp-8]  

       0x89, 0x08,                     // mov dword ptr [eax], ecx  

       0x8B, 0x45, 0x1C,               // mov eax, dword ptr [edx]  

       0x8B, 0x4D, 0xFC,               // mov ecx, dword ptr [ebp-4]  

       0x5E,                           // pop esi  

       0x89, 0x08,                     // mov dword ptr [eax], ecx  

       0x5B,                           // pop ebx  

       0xC9,                           // leave  

       0xC2, 0x18, 0x00                // ret 18h  

     };

     private static readonly byte[] CPUID_64_WINDOWS = new byte[] {

       0x48, 0x89, 0x5C, 0x24, 0x08,   // mov qword ptr [rsp+8], rbx  

       0x8B, 0xC1,                     // mov eax, ecx  

       0x8B, 0xCA,                     // mov ecx, edx        

       0x0F, 0xA2,                     // cpuid        

       0x41, 0x89, 0x00,               // mov dword ptr [r8], eax        

       0x48, 0x8B, 0x44, 0x24, 0x28,   // mov rax, qword ptr [rsp+28h]       

       0x41, 0x89, 0x19,               // mov dword ptr [r9], ebx        

       0x48, 0x8B, 0x5C, 0x24, 0x08,   // mov rbx, qword ptr [rsp+8]      

       0x89, 0x08,                     // mov dword ptr [rax], ecx        

       0x48, 0x8B, 0x44, 0x24, 0x30,   // mov rax, qword ptr [rsp+30h]  

       0x89, 0x10,                     // mov dword ptr [rax], edx  

       0xC3                            // ret  

     };

     private static readonly byte[] CPUID_64_LINUX = new byte[] {

       0x49, 0x89, 0xD2,               // mov r10, rdx

       0x49, 0x89, 0xCB,               // mov r11, rcx

       0x53,                           // push rbx

       0x89, 0xF8,                     // mov eax, edi

       0x89, 0xF1,                     // mov ecx, esi

       0x0F, 0xA2,                     // cpuid

       0x41, 0x89, 0x02,               // mov dword ptr [r10], eax

       0x41, 0x89, 0x1B,               // mov dword ptr [r11], ebx

       0x41, 0x89, 0x08,               // mov dword ptr [r8], ecx

       0x41, 0x89, 0x11,               // mov dword ptr [r9], edx

       0x5B,                           // pop rbx

       0xC3,                           // ret

     };

     public static bool CpuidTx(uint index, uint ecxValue, 

       out uint eax, out uint ebx, out uint ecx, out uint edx, 

       ulong threadAffinityMask) {

       ulong mask = ThreadAffinity.Set(threadAffinityMask);

       if (mask == 0) {

         eax = ebx = ecx = edx = 0;

         return false;

       } 

       Cpuid(index, ecxValue, out eax, out ebx, out ecx, out edx);

       ThreadAffinity.Set(mask);      

       return true;

     }

     [Flags()]

     public enum AllocationType : uint {

       COMMIT = 0x1000,

       RESERVE = 0x2000,

       RESET = 0x80000,

       LARGE_PAGES = 0x20000000,

       PHYSICAL = 0x400000,

       TOP_DOWN = 0x100000,

       WRITE_WATCH = 0x200000

     }

     [Flags()]

     public enum MemoryProtection : uint {

       EXECUTE = 0x10,

       EXECUTE_READ = 0x20,

       EXECUTE_READWRITE = 0x40,

       EXECUTE_WRITECOPY = 0x80,

       NOACCESS = 0x01,

       READONLY = 0x02,

       READWRITE = 0x04,

       WRITECOPY = 0x08,

       GUARD = 0x100,

       NOCACHE = 0x200,

       WRITECOMBINE = 0x400

     }

     [Flags]

     enum FreeType {

       DECOMMIT = 0x4000,

       RELEASE = 0x8000

     }

     private static class NativeMethods {      

       private const string KERNEL = "kernel32.dll";

       [DllImport(KERNEL, CallingConvention = CallingConvention.Winapi)]

       public static extern IntPtr VirtualAlloc(IntPtr lpAddress, UIntPtr dwSize,

         AllocationType flAllocationType, MemoryProtection flProtect);

       [DllImport(KERNEL, CallingConvention = CallingConvention.Winapi)]

       public static extern bool VirtualFree(IntPtr lpAddress, UIntPtr dwSize,

         FreeType dwFreeType);                 

     }

   }

 }