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Detecting the CPU type includes (Pentium)

{ This code comes from Intel, and has been modified for 
Delphi's inline assembler. } unit Cpu; interface uses SysUtils, WinTypes, WinProcs, Messages, Classes, Graphics,
Controls, Forms, Dialogs, StdCtrls, Buttons; type { All the types currently known. As new types are created,
add suitable names, and extend the case statement in the GetCpuType function.} TCPUType = (i8086CPU, i286CPU, i386CPU, i486CPU, iPentiumCPU); TForm1 = class(TForm) Edit1: TEdit; Label1: TLabel; BitBtn1: TBitBtn; procedure FormCreate(Sender: TObject); procedure BitBtn1Click(Sender: TObject); private { Return the type of the current CPU } function CpuType: TCPUType; { Return the type as a string } function GetCPUType: String; public end; var Form1: TForm1; { Define the winFlags variable for 286 check } winFlags: Longint; implementation {$R *.DFM} { Get CPU type } function TForm1.GetCPUType: String; var kind: TCPUType; begin if winFlags and WF_CPU286 > 0 then Result := '80286' else begin kind := CpuType; case kind of i8086CPU: Result := '8086'; i386CPU: Result := '80386'; i486CPU: Result := '80486'; iPentiumCPU: Result := 'Pentium'; else { Try to be flexible for future cpu types, e.g., P6. } Result := Format('P%d', [Ord(kind)]); end; end; end; { Assembly function to get CPU type including Pentium and later } function TForm1.CpuType: TCPUType; assembler; asm push DS { First check for an 8086 CPU } { Bits 12-15 of the FLAGS register are always set on the 8086 processor. } pushf { save EFLAGS } pop bx { store EFLAGS in BX } mov ax,0fffh { clear bits 12-15 } and ax,bx { in EFLAGS } push ax { store new EFLAGS value on stack } popf { replace current EFLAGS value } pushf { set new EFLAGS } pop ax { store new EFLAGS in AX } and ax,0f000h { if bits 12-15 are set, then CPU } cmp ax,0f000h { is an 8086/8088 } mov ax, i8086CPU { turn on 8086/8088 flag } je @@End_CpuType { 80286 CPU check } { Bits 12-15 of the FLAGS register are always clear on the 80286 processor. } { Commented out because 'pop ax' crashes it to the DOS prompt when running } { with a Delphi form on some Machines.} { or bx,0f000h } { try to set bits 12-15 } { push bx } { popf } { pushf } { pop ax } { This crashes Delphi programs on some machines } { and ax,0f000h } { if bits 12-15 are cleared, CPU=80286 } { mov ax, i286CPU } { turn on 80286 flag } { jz @@End_CpuType } { To test for 386 or better, we need to use 32 bit instructions, but the 16-bit Delphi assembler does not recognize the 32 bit opcodes or operands. Instead, use the 66H operand size prefix to change each instruction to its 32-bit equivalent. For 32-bit immediate operands, we also need to store the high word of the operand immediately following the instruction. The 32-bit instruction is shown in a comment after the 66H instruction. } { i386 CPU check } { The AC bit, bit #18, is a new bit introduced in the EFLAGS } { register on the i486 DX CPU to generate alignment faults. } { This bit can not be set on the i386 CPU. } db 66h { pushfd } pushf db 66h { pop eax } pop ax { get original EFLAGS } db 66h { mov ecx, eax } mov cx,ax { save original EFLAGS } db 66h { xor eax,40000h } xor ax,0h { flip AC bit in EFLAGS } dw 0004h db 66h { push eax } push ax { save for EFLAGS } db 66h { popfd } popf { copy to EFLAGS } db 66h { pushfd } pushf { push EFLAGS } db 66h { pop eax } pop ax { get new EFLAGS value } db 66h { xor eax,ecx } xor ax,cx { can't toggle AC bit, CPU=Intel386 } mov ax, i386CPU { turn on 386 flag } je @@End_CpuType { i486 DX CPU / i487 SX MCP and i486 SX CPU checking } { Checking for ability to set/clear ID flag (Bit 21) in EFLAGS } { which indicates the presence of a processor } { with the ability to use the CPUID instruction. } db 66h { pushfd } pushf { push original EFLAGS } db 66h { pop eax } pop ax { get original EFLAGS in eax } db 66h { mov ecx, eax } mov cx,ax { save original EFLAGS in ecx } db 66h { xor eax,200000h } xor ax,0h { flip ID bit in EFLAGS } dw 0020h db 66h { push eax } push ax { save for EFLAGS } db 66h { popfd } popf { copy to EFLAGS } db 66h { pushfd } pushf { push EFLAGS } db 66h { pop eax } pop ax { get new EFLAGS value } db 66h { xor eax, ecx } xor ax, cx mov ax, i486CPU { turn on i486 flag } je @@End_CpuType { if ID bit cannot be changed, CPU=486 } { without CPUID instruction functionality } { Execute CPUID instruction to determine vendor, family, } { model and stepping. The use of the CPUID instruction used } { in this program can be used for B0 and later steppings } { of the P5 processor. } db 66h { mov eax, 1 } mov ax, 1 { set up for CPUID instruction } dw 0 db 66h { cpuid } db 0Fh { Hardcoded opcode for CPUID instruction } db 0a2h db 66h { and eax, 0F00H } and ax, 0F00H { mask everything but family } dw 0 db 66h { shr eax, 8 } shr ax, 8 { shift the cpu type down to the low byte } sub ax, 1 { subtract 1 to map to TCpuType } @@End_CpuType: pop ds end; { Get the Windows Flags to check for 286. The 286 assembly code
crashes due to a problem when using with Delphi Forms on some machines. This method is safer.} procedure TForm1.FormCreate(Sender: TObject); begin winFlags := GetWinFlags; end; { Call the CPU function and assign it to the Edit box } procedure TForm1.BitBtn1Click(Sender: TObject); begin Edit1.Text := GetCPUType; end; end.

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Copyright © 1996 Asylum Software Pvt. Ltd. This is an ASPL production.
Produced in conjunction with ASPL DELPHI TEAM.
Last revised November 27, 1996.