CPUID詳解

標 題: CPUID詳解[增加TLB與Cache]
作 者: Pr0Zel
時 間: 2006-02-21 22:00
鏈 接: http://bbs.pediy.com/showthread.php?threadid=21646
詳細信息:

這是文章最後一次更新,加入了TLB與Cache信息等資料
前言:論壇上面有人不明白CPUID指令的用法,於是就萌生寫這篇文章的想法,
若有錯誤話請大俠指出,謝謝了 ^^
論壇的式樣貌似有問題,若式樣問題導致閱讀問題的話,可以在文章尾下載txt文檔閱讀.

論壇上面有人不明白CPUID指令的用法,於是就萌生寫這篇文章的想法,
若有錯誤話請大俠指出,謝謝了 ^^
CPUID是Intel Pentium以上級CPU內置的一個指令(486級及以下的CPU不支持),它用於識別某一類型的CPU,它能返回CPU的級 別(family),型號(model),CPU步進(Stepping ID)及CPU字串等信息,從此命令也可以得到CPU的緩存與TLB信息.
CPUID返回數據類型是在EAX寄存器裡面定義的,而指令返回的數值則在存儲在EAX,EBX,ECX和EDX寄存器裡面.
返回的信息分兩部分:基本信息與擴展信息.在EAX輸入0-3參數時,它返回的CPU的基本信息;而在EAX輸入0x8000000至0x800000x 時,它返回的是CPU的擴展信息(extended function information).擴展信息只包含在Pentium 4及以後的CPU 上,Pentium 4以前的CPU無法取得它的擴展信息.

如下面的表:
CPU級別 基本信息 擴展信息
486及以前的CPU 不可用 不可用
Pentium 0x1 不可用
Pentium Pro,Pentium 2 0x2 不可用
Pentium 3 0x3 不可用
Pentium 4 0x2 0x80000004
Xeon(至強) 0x2 0x80000004

假若輸入高於該處理器的值時,CPUID指令返回的是該CPU的輸入最高值的返回值(這一句不知道怎麼說才好),
比如在在Pentium 4上輸入0x4,則CPU返回值與輸入0x2的返回值一樣.

下面的表是輸入值與返回值的關係:
輸入值 返回值
-----------------------------------------------------------------
0x0 EAX CPU基本參數的輸入值
EBX "Genu"
ECX "Intel"
EDX "inel"
------------------------------------------------------------------
0x1 EAX CPU的級別,型號及步進
EBX 信息很多,下面介紹
ECX 保留
EDX 特徵信息(Feature Information)
------------------------------------------------------------------
0x2 EAX到EDX返回的都是緩存和TLB的信息
------------------------------------------------------------------
0x3 EAX 保留
EBX 保留
ECX CPU序列號(0 - 31bit) (只是在Pentium 3中才有效)
EDX CPU序列號(32 - 63bit) (只是在Pentium 3 中才有效)
------------------------------------------------------------------

0x80000000 EAX 擴展信息輸入數最大值(具有擴展信息的CPU才能返回)
EBX 保留
ECX 保留
EDX 保留
------------------------------------------------------------------
0x80000001 EAX CPU特徵(Signature)和擴展特徵位(Extended Feature Bits)
EBX 到 ECX 保留
------------------------------------------------------------------
0x80000002 EAX 處理器字串(Processor Brand String)
EBX 處理器字串(續)
ECX 處理器字串(續)
EDX 處理器字串(續)
------------------------------------------------------------------
0x80000003 EAX 處理器字串(續)
EBX 處理器字串(續)
ECX 處理器字串(續)
EDX 處理器字串(續)
------------------------------------------------------------------
0x80000004 EAX 處理器字串(續)
EBX 處理器字串(續)
ECX 處理器字串(續)
EDX 處理器字串(續)
------------------------------------------------------------------

當輸入0x1時,EBX返回值是:
第 0 - 7位: CPU字串索引 (Brand Index)
第 8 - 15位: CLFLUSH線大小(CLFLUSH line size) (返回值*8 = cache line size)
第16 - 23位: 保留
第24 - 31位: 處理器APIC物理標號 (Processor local APIC physical ID)

當輸入0x1時,EDX返回的擴展信息解釋如下:

位 標號 解釋
0 FPU Floating Point Unit On-Chip. CPU是否內置浮點計算單元
1 VME Virtual 8086 Mode Enhancements. 是否支持虛擬8086模式
2 DE Debugging Extensions. 是否支持調試功能.
3 PSE Page Size Extension. 是否支持大於4MB的分頁.
4 TSC Time Stamp Counter. 是否支持RDTSC指令.(注:RDTSC指令可以計算出CPU的頻率)
5 MSR Module Specific Registers RDMSR and WRMSR Instructions. 是否支持RDMSR與WRMSR (*注1)
6 PAE Physical Address Extension. 是否支持大於32bit的物理地址.
7 MCE Machine Check Exception. (*注2)
8 CX8 CMPXCHG8B Instruction. 是否支持8bytes(64bit)數的比較與交換指令.
9 APIC APIC On-Chip.是否支持APIC(Advanced Programmable Interrupt Controller)
10 保留
11 SEP SYSENTER and SYSEXIT Instructions.是否支持SYSENTER與SYSEXIT指令.(*注3)
12 MTRR Memory Type Range Registers. 是否支持MTTR(*注4)
13 PGE PTE Global Bit. 是否支持全局頁面目錄入口標誌位 (global bit in page directory entries)
14 MCA Machine Check Architecture. 是否支持MCA,MCA是Pentium4,Xeon,P6級處理器的一個錯誤報告機制
15 CMOV Conditional Move Instructions. CMOV指令是否可用.(請問誰可以解釋一下CMOV是什麼命令?)
16 PAT Page Attribute Table. 是否支持PAT,PAT允許操作系統指定4K大小的線性內存空間
17 PSE-36 32-bit Page Size Extension. 是否支持4GB的擴展內存
18 PSN Processor Serial Number. 是否支持處理器序列號.(P3有效)
19 CLFSH CLFLUSH Instruction.是否支持CLFLUSH.(*注5)
20 保留
21 DS Debug Store. 是否支持把調試信息寫入緩存,
22 ACPI ACPI Processor Performance Modulation Registers. 處理器使用特別的寄存器以允許軟件控制處理器的運行週期.
23 MMX Inter MMX Technology.是否支持MMX
24 FXSR FXSAVE and FXRSTOR Instructions. FXSAVE與FXRSTOR指令是否可用(*注6)
25 SSE SSE.是否支持SSE.
26 SSE2 是否支持SSE2.
27 SS Self Snoop. 處理器是否支持總線監視,以防止儲存器衝突.
28 保留
29 TM Thermal Monitor.CPU是否支持溫度控制.
30 & 31 保留
--------------------------------------------------------------
注1: RDMSR: Load MSR specified by ECX into EDX:EAX
WRMSR: Write the value in EDX:EAX to MSR specified by ECX
注2:
原文是 Exception 18 is defined for Machine Checks,including CR4.MCE for controlling the feature. This feature does not define themodel-specific implementations of machine-check error logging, reporting, andprocessor shutdowns. Machine Check exception handlers may have to depend onprocessor version to do model specific processing of the exception, or test for thepresence of the Machine Check feature.

注3: SYSENTER: Fast call to privilege level 0 system procedures
SYSEXIT: Fast return to privilege level 3 user code.

注4:
原文是 The MTRRcap MSR contains feature bits that describe what memory types are supported, how manyvariable MTRRs are supported, and whether fixed MTRRs are supported.

注5: CLFLUSH: Flushes cache line containing m8.

注6: FXSAVE: Save the x87 FPU, MMX, XMM, and MXCSR register
FXSTOR: Restore the x87 FPU, MMX, XMM, and MXCSR register


按照這個,就可以自己寫一個CPU檢測程序了;


#include

void main()
{
unsigned long DBaseIndex, DFeInfo, DFeInfo2, DCPUBaseInfo;
unsigned long DFeIndex, DCPUExInfo, i;
unsigned long DOther[4], DTLB[4], DProceSN[2];
char cCom[13];
char cProStr[49];
unsigned int j;

_asm
{
xor eax, eax
cpuid
mov DBaseIndex ,eax
mov dword ptr cCom ,ebx
mov dword ptr cCom+4 ,ecx //AMD CPU要把ecx改為edx
mov dword ptr cCom+8 ,edx //AMD CPU要把edx改為ecx

mov eax, 1
cpuid
mov DCPUBaseInfo, eax
mov DFeInfo, ebx
mov DFeInfo2, edx

mov eax, 0x80000000
cpuid
mov DFeIndex, eax

mov eax, 0x80000001
cpuid
mov DCPUExInfo, eax

mov eax, 0x80000002
cpuid
mov dword ptr cProStr , eax
mov dword ptr cProStr + 4 , ebx
mov dword ptr cProStr + 8 , ecx
mov dword ptr cProStr + 12 ,edx

mov eax, 0x80000003
cpuid
mov dword ptr cProStr + 16 , eax
mov dword ptr cProStr + 20 , ebx
mov dword ptr cProStr + 24 , ecx
mov dword ptr cProStr + 28 , edx

mov eax, 0x80000004
cpuid
mov dword ptr cProStr + 32 , eax
mov dword ptr cProStr + 36 , ebx
mov dword ptr cProStr + 40 , ecx
mov dword ptr cProStr + 44 , edx
}

if( DBaseIndex >= 2 )
{
_asm
{
mov eax, 2
cpuid
mov DTLB[0], eax
mov DTLB[2], ebx
mov DTLB[3], ecx
mov DTLB[4], edx
}
}
if(DBaseIndex == 3)
{
_asm
{
mov eax, 3
cpuid
mov DProceSN[0], ecx
mov DProceSN[1], edx
}
}

cCom[12] = '\0'; //加一個結尾符
printf( "CPU廠商: %s\n", cCom );
printf( "CPU字串: %s\n", cProStr );
printf( "CPU基本參數: Family:%X Model:%X Stepping ID:%X\n", (DCPUBaseInfo & 0x0F00) >> 8,
(DCPUBaseInfo & 0xF0) >> 4, DCPUBaseInfo & 0xF );
printf( "CPU擴展參數: Family:%X Model:%X Stepping ID:%X\n", (DCPUExInfo & 0x0F00) >> 8,
(DCPUExInfo & 0xF0) >> 4, DCPUExInfo & 0xF );

printf( "CPU字串索引: 0x%X\n", DFeInfo & 0xFF );
printf( "CLFLUSH線大小: 0x%X\n", ( DFeInfo & 0xFF00 ) >> 8 );
printf ( "處理器APIC物理標號:0x%X\n", ( DFeInfo & 0xF000 ) >> 24 );
if( DBaseIndex >= 2)
{
printf( "CPU Cache & TLB Information: " );
for(j = 0; j <>> 8) ) printf( "%.2X ", (DTLB[j] & 0xFF00) >> 8 );
if( !((DTLB[j] & 0xFF0000) >> 16) ) printf( "%.2X ",( DTLB[j] & 0xFF0000) >> 16);
if( !((DTLB[j] & 0xFF000000) >> 24) ) printf( "%.2X ",( DTLB[j] & 0xFF000000) >> 24);
}
printf("\n");
}

if( DBaseIndex == 3 )
{
printf( "CPU序列號是:%X%X\n", DProceSN[0], DProceSN[1] );
}
printf( "FPU: %d\t\t", DFeInfo2 & 0x00000001 ); //下面是調用某BLOG上面的代碼,懶得寫了 ^^
printf( "VME: %d\t\t", (DFeInfo2 & 0x00000002 ) >> 1 );
printf( "DE: %d\n", (DFeInfo2 & 0x00000004 ) >> 2 );
printf( "PSE: %d\t\t", (DFeInfo2 & 0x00000008 ) >> 3 );
printf( "TSC: %d\t\t", (DFeInfo2 & 0x00000010 ) >> 4 );
printf( "MSR: %d\n", (DFeInfo2 & 0x00000020 ) >> 5 );
printf( "PAE: %d\t\t", (DFeInfo2 & 0x00000040 ) >> 6 );
printf( "MCE: %d\t\t", (DFeInfo2 & 0x00000080 ) >> 7 );
printf( "CX8: %d\n", (DFeInfo2 & 0x00000100 ) >> 8 );
printf( "APIC: %d\t", (DFeInfo2 & 0x00000200 ) >> 9 );
printf( "SEP: %d\t\t", (DFeInfo2 & 0x00000800 ) >> 11 );
printf( "MTRR: %d\n", (DFeInfo2 & 0x00001000 ) >> 12 );
printf( "PGE: %d\t\t", (DFeInfo2 & 0x00002000 ) >> 13 );
printf( "MCA: %d\t\t", (DFeInfo2 & 0x00004000 ) >> 14 );
printf( "CMOV: %d\n", (DFeInfo2 & 0x00008000 ) >> 15 );
printf( "PAT: %d\t\t", (DFeInfo2 & 0x00010000 ) >> 16 );
printf( "PSE-36: %d\t", (DFeInfo2 & 0x00020000 ) >> 17 );
printf( "PSN: %d\n", (DFeInfo2 & 0x00040000 ) >> 18 );
printf( "CLFSN: %d\t", (DFeInfo2 & 0x00080000 ) >> 19 );
printf( "DS: %d\t\t", (DFeInfo2 & 0x00200000 ) >> 21 );
printf( "ACPI: %d\n", (DFeInfo2 & 0x00400000 ) >> 22 );
printf( "MMX: %d\t\t", (DFeInfo2 & 0x00800000 ) >> 23 );
printf( "FXSR: %d\t", (DFeInfo2 & 0x01000000 ) >> 24 );
printf( "SSE: %d\n", (DFeInfo2 & 0x02000000 ) >> 25 );
printf( "SSE2: %d\t", (DFeInfo2 & 0x04000000 ) >> 26 );
printf( "SS: %d\t\t", (DFeInfo2 & 0x08000000 ) >> 27 );
printf( "TM: %d\n", (DFeInfo2 & 0x20000000 ) >> 29 );

printf("\n其它信息:\n");
printf("----------------------------------------\n");
printf("In \t\tEAX \t\tEBX \t\tECX \t\tEDX");
for( i = 0x80000004; i <= DFeIndex; ++i ) { DOther[0] = DOther[1] = DOther[2] = DOther[3] = 0; _asm { mov eax, i cpuid mov DOther[0], eax mov DOther[1], ebx mov DOther[2], ecx mov DOther[3], edx } printf( "\n0x%.8X\t0x%.8X\t0x%.8X\t0x%.8X\t0x%.8X", i, DOther[0], DOther[1], DOther[2], DOther[3] ); } printf( "\n" ); system( "pause" ); }


TLB與Cache信息詳解:
0x00 Null descriptor
0x01 Instruction TLB: 4K-Byte Pages, 4-way set associative, 32 entries 0x02 Instruction TLB: 4M-Byte Pages, 4-way set associative, 2 entries
0x03 Data TLB: 4K-Byte Pages, 4-way set associative, 64 entries
0x04 Data TLB: 4M-Byte Pages, 4-way set associative, 8 entries
0x06 1st-level instruction cache: 8K Bytes, 4-way set associative, 32 byte line size
0x08 1st-level instruction cache: 16K Bytes, 4-way set associative, 32 byte line size
0x0A 1st-level data cache: 8K Bytes, 2-way set associative, 32 byte line size
0x0C 1st-level data cache: 16K Bytes, 4-way set associative, 32 byte line size 0x22 3rd-level cache: 512K Bytes, 4-way set associative, 64 byte line size
0x23 3rd-level cache: 1M Bytes, 8-way set associative, 64 byte line size
0x25 3rd-level cache: 2M Bytes, 8-way set associative, 64 byte line size
0x29 3rd-level cache: 4M Bytes, 8-way set associative, 64 byte line size
0x40 No 2nd-level cache or, if processor contains a valid 2nd-level cache, no 3rd-level cache
0x41 2nd-level cache: 128K Bytes, 4-way set associative, 32 byte line size
0x42 2nd-level cache: 256K Bytes, 4-way set associative, 32 byte line size
0x43 2nd-level cache: 512K Bytes, 4-way set associative, 32 byte line size
0x44 2nd-level cache: 1M Byte, 4-way set associative, 32 byte line size
0x45 2nd-level cache: 2M Byte, 4-way set associative, 32 byte line size
0x50 Instruction TLB: 4-KByte and 2-MByte or 4-MByte pages, 64 entries
0x51 Instruction TLB: 4-KByte and 2-MByte or 4-MByte pages, 128 entries
0x52 Instruction TLB: 4-KByte and 2-MByte or 4-MByte pages, 256 entries
0x5B Data TLB: 4-KByte and 4-MByte pages, 64 entries
0x5C Data TLB: 4-KByte and 4-MByte pages,128 entries
0x5D Data TLB: 4-KByte and 4-MByte pages,256 entries
0x66 1st-level data cache: 8KB, 4-way set associative, 64 byte line size
0x67 1st-level data cache: 16KB, 4-way set associative, 64 byte line size
0x68 1st-level data cache: 32KB, 4-way set associative, 64 byte line size
0x70 Trace cache: 12K-μop, 8-way set associative
0x71 Trace cache: 16K-μop, 8-way set associative
0x72 Trace cache: 32K-μop, 8-way set associative
0x79 2nd-level cache: 128KB, 8-way set associative, sectored, 64 byte line size 0x7A 2nd-level cache: 256KB, 8-way set associative, sectored, 64 byte line size 0x7B 2nd-level cache: 512KB, 8-way set associative, sectored, 64 byte line size 0x7C 2nd-level cache: 1MB, 8-way set associative, sectored, 64 byte line size
0x82 2nd-level cache: 256K Bytes, 8-way set associative, 32 byte line size
0x84 2nd-level cache: 1M Byte, 8-way set associative, 32 byte line size
0x85 2nd-level cache: 2M Byte, 8-way set associative, 32 byte line size

舉一個例子,一個CPU執行 mov eax, 2 cpuid 後, 返回值如下:
EAX 0x665B5001 EBX 0x0 ECX 0x0 EDX 0x007A7000

就代表了這個CPU的Cache信息是:
1. 0x66:1st-level data cache: 8KB, 4-way set associative, 64 byte line size
2. 0x5B:Data TLB: 4-KByte and 4-MByte pages, 64 entries
3. 0x50:Instruction TLB: 4-KByte and 2-MByte or 4-MByte pages, 64 entries
4. 0x01:Instruction TLB: 4K-Byte Pages, 4-way set associative, 32 entries
5. 0x7A:2nd-level cache: 256KB, 8-way set associative, sectored, 64 byte line size 6. 0x70:Trace cache: 12K-μop, 8-way set associative

CPU字串索引 (Brand Index)詳解:
0x0: CPU不支持Brand Index
0x1: Celeron CPU
0x2: Pentium 3
0x3: Pentium 3 Xeon
0x4-0x7: 未用
0x8: Pentium 4 可惜我是用AMD CPU的,有好些功能都不能親自試驗
參考資料:IA-32 Intel Architecture Software Developer's Manual