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/* Project:     OSLib

 * Description: The OS Construction Kit

 * Date:                1.6.2000

 * Idea by:             Luca Abeni & Gerardo Lamastra

 *

 * OSLib is an SO project aimed at developing a common, easy-to-use

 * low-level infrastructure for developing OS kernels and Embedded

 * Applications; it partially derives from the HARTIK project but it

 * currently is independently developed.

 *

 * OSLib is distributed under GPL License, and some of its code has

 * been derived from the Linux kernel source; also some important

 * ideas come from studying the DJGPP go32 extender.

 *

 * We acknowledge the Linux Community, Free Software Foundation,

 * D.J. Delorie and all the other developers who believe in the

 * freedom of software and ideas.

 *

 * For legalese, check out the included GPL license.

 */

/*	CPU detection code	*/

.title	"CPU2.S"

#include <ll/i386/linkage.h>

#include <ll/i386/defs.h>

/*

 * The following code has been extracted by Intel AP-485

 * Application Note: Intel Processor Identification with CPUID instruction

 */

.data

ASMFILE(CPU2)

.globl	SYMBOL_NAME(X86_fpu)

SYMBOL_NAME_LABEL(X86_fpu)		.byte	0

SYMBOL_NAME_LABEL(X86_cpu)		.byte	0

fpu_status:	.word	0

/*

	struct CPU {

		DWORD X86_cpu;			0

		DWORD X86_cpuIdFlag;		4

		DWORD X86_vendor_1;		8

		DWORD X86_vendor_2;		12

		DWORD X86_vendor_3;		16

		DWORD X86_signature;		20

		DWORD X86_IntelFeature_1;	24

		DWORD X86_IntelFeature_2;	28

		DWORD X86_StandardFeature;	32

	}

*/

.text

.globl SYMBOL_NAME(X86_get_CPU)

.globl SYMBOL_NAME(X86_get_FPU)

.globl SYMBOL_NAME(X86_is386)

.globl SYMBOL_NAME(X86_isCyrix)

.globl SYMBOL_NAME(X86_hasCPUID)

.globl SYMBOL_NAME(X86_enable_cyrix_cpuid)

SYMBOL_NAME_LABEL(X86_is386)

		pushfl

		popl	%eax

		movl	%eax, %ecx

		xorl	$0x40000, %eax

		pushl	%eax

		popfl

		pushfl

		popl	%eax

		cmp	%ecx, %eax

		jz	is386

		pushl	%ecx

		popfl

		movl	$0, %eax

		ret

is386:

		movl	$1, %eax

		ret

SYMBOL_NAME_LABEL(X86_enable_cyrix_cpuid)

		pushfl

		cli

   		/* Get Cyrix reg c3h */

		movb   $0xc3,%al

   		outb   %al,$0x22

   		inb    $0x23,%al

   		/* Enable config access */

   		movb   %al,%cl

   		movb   %al,%bl

   		andb   $0xf,%bl

   		orb    $0x10,%bl

   		/* Set Cyrix reg c3h */

   		movb   $0xc3,%al

   		outb   %al,$0x22

		movb   %bl,%al

		outb   %al,$0x23

   		/* Get Cyrix reg e8 */

		movb   $0xe8,%al

		outb   %al,$0x22

		inb    $0x23,%al

		/* Set "CPUID" bit */

   		orb    $0x80,%al

		movb   %al,%bl

		/* Set Cyrix reg e8 */

		movb   $0xe8,%al

		outb   %al,$0x22

		movb   %bl,%al

		outb   %al,$0x23

		/* Get Cyrix reg fe */

		movb   $0xfe,%al

		outb   %al,$0x22

		inb    $0x23,%al

		/* Is CPU a 6x86(L)? */

		andb   $0xf0,%al

		cmpb   $0x30,%al

		jne   not6x86

		/* Get Cyrix reg e9 */

		movb   $0xe9,%al

		outb   %al,$0x22

		inb    $0x23,%al

		/* Fix 6x86 SLOP bug */

		andb   $0xfd,%al

		movb   %al,%bl

		/* Set Cyrix reg e9 */

		movb   $0xe9,%al

		outb   %al,$0x22

		movb   %bl,%al

		outb   %al,$0x23

not6x86:

		/* Set Cyrix reg c3 */

		movb   $0xc3,%al

		outb   %al,$0x22

		movb   %cl,%al

		outb   %al,$0x23

		/* Disable suspended mode */

		movb   $0xc2,%al

		outb   %al,$0x22

		inb    $0x23,%al

		andb   $0x7F,%al

		movb   %al,%bl

		movb   $0xc2,%al

                outb   %al,$0x22

                movb   %bl,%al

                outb   %al,$0x23

		popfl

		ret

SYMBOL_NAME_LABEL(X86_hasCPUID)

		pushfl

		popl	%eax

		movl	%eax, %ecx

		xorl	$0x200000, %eax

		pushl	%eax

		popfl

		pushfl

		popl	%eax

		xorl	%ecx, %eax

		je	noCPUID

		pushl	%ecx	/* Restore the old EFLAG value... */

		popfl

		movl	$1, %eax

		ret

noCPUID:

		movl	$0, %eax

		ret

SYMBOL_NAME_LABEL(X86_isCyrix)

		xorw	%ax, %ax

		sahf

		mov	$5, %ax

		mov	$2, %bx

		divb	%bl

		lahf

		cmpb	$2, %ah

		jne	noCyrix

		movl	$1, %eax

		ret

noCyrix:

		movl	$0, %eax

		ret

SYMBOL_NAME_LABEL(X86_get_FPU)

	/* First of all, set the FPU type to 0... */

		movb	$0, SYMBOL_NAME(X86_fpu)

		fninit

	/* Let's give some time to the FPU...

	 * We cannot use WAIT 'cause we don't know if an FPU is present...

	 */

		movl	$2, %ecx

here:

		loop	here

		movw	$0x5a5a, fpu_status

		fnstsw	fpu_status

	/* Guys, I really don't know when to wai and when not...

	 */

		movl	$2, %ecx

here1:

		loop	here1

		movw	fpu_status, %ax

		cmpb	$0, %al

		jne	endFPUProc

chkCW:

	/* OK, if we are here, we have some kind of FPU... */

		fnstcw 	fpu_status

	/* Guys, I really don't know when to wai and when not...

	 */

		movl	$2, %ecx

here2:

		loop	here2

		movw	fpu_status, %ax

		andw	$0x103f, %ax

		cmpw	$0x03F, %ax

		jne	endFPUProc

	/* ... Err... I was wrong :(. Here we are sure to have an FPU */

		movb	$1, SYMBOL_NAME(X86_fpu)

chkInf:

/* Well... I assume that if we arrive to X86_get_FPU, we are running on a

 * 386+ processor... Hence, the following is a complete nonsense!!!

 * I'm commenting it out, we will see...

 */

#if 0

	/* Um... If we have a -386, end of the story! */

		cmpb	$3, SYMBOL_NAME(X86_cpu)

		jle	endFPUProc

		movb	$2, SYMBOL_NAME(X86_fpu)

		fld1

		fldz

		fdivp

		fld	%st

		fchs

		fcompp

		fstsw	fpu_status

		wait

		sahf

		jz	endFPUProc

		movb	$3, SYMBOL_NAME(X86_fpu)

#else

		movb	$3, SYMBOL_NAME(X86_fpu)

#endif

endFPUProc:

		ret