4 files changed, 115 insertions(+), 66 deletions(-)

M pc/clock.c
M pc/fns.h
M pc/l.s
M pc/main.c

@@ 29,9 29,8 @@ enum
 
 static int cpufreq = 66000000;
 static int cpumhz = 66;
-static int cputype = 486;
 static int loopconst = 100;
-ulong cpuidax, cpuiddx;
+static int cpuidax, cpuiddx;
 
 static void
 clock(Ureg *ur, void *arg)


@@ 72,6 71,49 @@ clock(Ureg *ur, void *arg)
 	mouseclock();
 }
 
+#define STEPPING(x)	((x)&0xf)
+#define MODEL(x)	(((x)>>4)&0xf)
+#define FAMILY(x)	(((x)>>8)&0xf)
+
+enum
+{
+	/* flags */
+	CpuidFPU	= 0x001,	/* on-chip floating point unit */
+	CpuidMCE	= 0x080,	/* machine check exception */
+	CpuidCX8	= 0x100,	/* CMPXCHG8B instruction */
+};
+
+typedef struct
+{
+	int family;
+	int model;
+	int aalcycles;
+	char *name;
+} X86type;
+
+X86type x86type[] =
+{
+	/* from the cpuid instruction */
+	{ 4,	0,	22,	"Intel486DX", },
+	{ 4,	1,	22,	"Intel486DX", },
+	{ 4,	2,	22,	"Intel486SX", },
+	{ 4,	4,	22,	"Intel486DX2", },
+	{ 4,	5,	22,	"Intel486SL", },
+	{ 4,	8,	22,	"IntelDX4", },
+	{ 5,	1,	23,	"Pentium510", },
+	{ 5,	2,	23,	"Pentium735", },
+
+	/* family defaults */
+	{ 3,	-1,	32,	"Intel386", },
+	{ 4,	-1,	22,	"Intel486", },
+	{ 5,	-1,	23,	"Pentium", },
+
+	/* total default */
+	{ -1,	-1,	23,	"unknown", },
+};
+
+static X86type	*cputype;
+
 /*
  *  delay for l milliseconds more or less.  delayloop is set by
  *  clockinit() to match the actual CPU speed.


@@ 89,26 131,18 @@ printcpufreq(void)
 		cpufreq, cputype, cpuidax, cpuiddx);
 }
 
+int
+x86(void)
+{
+	return cputype->family;
+}
+
 void
 clockinit(void)
 {
-	ulong x, y;	/* change in counter */
-	ulong cycles, loops;
-
-	switch(cputype = x86()){
-	case 386:
-		loops = 10000;
-		cycles = 32;
-		break;
-	case 486:
-		loops = 10000;
-		cycles = 22;
-		break;
-	default:
-		loops = 30000;
-		cycles = 23;
-		break;
-	}
+	int x, y;	/* change in counter */
+	int family, model, loops;
+	X86type *t;
 
 	/*
 	 *  set vector for clock interrupts


@@ 116,45 150,65 @@ clockinit(void)
 	setvec(Clockvec, clock, 0);
 
 	/*
+	 *  figure out what we are
+	 */
+	x86cpuid(&cpuidax, &cpuiddx);
+	family = FAMILY(cpuidax);
+	model = MODEL(cpuidax);
+	for(t = x86type; t->name; t++)
+		if((t->family == family && t->model == model)
+		|| (t->family == family && t->model == -1)
+		|| (t->family == -1))
+			break;
+	cputype = t;
+
+	/*
 	 *  set clock for 1/HZ seconds
 	 */
 	outb(Tmode, Load0|Square);
 	outb(T0cntr, (Freq/HZ));	/* low byte */
 	outb(T0cntr, (Freq/HZ)>>8);	/* high byte */
 
-
-	/*
-	 *  measure time for the loop
-	 *
-	 *			MOVL	loops,CX
-	 *	aaml1:	 	AAM
-	 *			LOOP	aaml1
-	 *
-	 *  the time for the loop should be independent from external
-	 *  cache's and memory system since it fits in the execution
-	 *  prefetch buffer.
-	 *
-	 */
-	outb(Tmode, Latch0);
-	x = inb(T0cntr);
-	x |= inb(T0cntr)<<8;
-	aamloop(loops);
-	outb(Tmode, Latch0);
-	y = inb(T0cntr);
-	y |= inb(T0cntr)<<8;
-	x -= y;
-
-	/*
-	 *  counter  goes at twice the frequency, once per transition,
-	 *  i.e., twice per square wave
-	 */
-	x >>= 1;
-
-	/*
- 	 *  figure out clock frequency and a loop multiplier for delay().
-	 */
-	cpufreq = loops*((cycles*Freq)/x);
-	loopconst = (cpufreq/1000)/cycles;	/* AAM+LOOP's for 1 ms */
+	/* use biggest loop that works */
+	for(loops = 10000; ; loops += 5000) {
+		/*
+		 *  measure time for the loop
+		 *
+		 *			MOVL	loops,CX
+		 *	aaml1:	 	AAM
+		 *			LOOP	aaml1
+		 *
+		 *  the time for the loop should be independent of external
+		 *  cache and memory system since it fits in the execution
+		 *  prefetch buffer.
+		 *
+		 */
+		outb(Tmode, Latch0);
+		x = inb(T0cntr);
+		x |= inb(T0cntr)<<8;
+		aamloop(loops);
+		outb(Tmode, Latch0);
+		y = inb(T0cntr);
+		y |= inb(T0cntr)<<8;
+		x -= y;
+
+		if(x < 0)
+			x += 2^16;
+		if(x > (2^15))
+			break;
+	
+		/*
+		 *  counter  goes at twice the frequency, once per transition,
+		 *  i.e., twice per square wave
+		 */
+		x >>= 1;
+
+		/*
+	 	 *  figure out clock frequency and a loop multiplier for delay().
+		 */
+		cpufreq = loops*((t->aalcycles*Freq)/x);
+		loopconst = (cpufreq/1000)/t->aalcycles;	/* AAM+LOOP's for 1 ms */
+	} while(x > 0);
 
 	/*
 	 *  add in possible .1% error and convert to MHz

@@ 91,6 91,7 @@ void	vgainit(void);
 void	vgasavecrash(uchar*, int);
 void	vgarestorecrash(uchar*, int);
 int	x86(void);
+int	x86cpuid(int*, int*);
 
 #define	waserror()	(up->nerrlab++, setlabel(&up->errlab[up->nerrlab-1]))
 #define	kmapperm(x)	kmap(x)

@@ 572,7 572,7 @@ TEXT	getstatus(SB),$0
 /*
  *  return cpu type (586 == pentium or better)
  */
-TEXT	x86(SB),$0
+TEXT	x86cpuid(SB),$0
 
 	PUSHFL
 	MOVL	0(SP),AX


@@ 591,22 591,17 @@ TEXT	x86(SB),$0
 	/* CPUID */
 	 BYTE $0x0F
 	 BYTE $0xA2
-
-	MOVL	AX, cpuidax(SB)
-	MOVL	DX, cpuiddx(SB)
-
-	SHLL	$20,AX
-	SHRL	$28,AX
-	CMPL	AX, $4
-	JEQ	is486
-	MOVL	$586,AX
 	JMP	done
 is486:
-	MOVL	$486,AX
+	MOVL	$(4<<8),AX
+	MOVL	$0,DX
 	JMP	done
 is386:
-	MOVL	$386,AX
+	MOVL	$(3<<8),AX
+	MOVL	$0,DX
 done:
+	MOVL	AX, a+0(FP)
+	MOVL	DX, d+4(FP)
 	POPL	BX
 	POPFL
 	RET

@@ 448,11 448,10 @@ confinit(void)
 	conf.nswap = conf.nproc*80;
 	conf.nimage = 50;
 	switch(x86()){
-	case 386:
+	case 3:
 		conf.copymode = 1;	/* copy on reference */
 		break;
 	default:
-	case 486:
 		conf.copymode = 0;	/* copy on write */
 		break;
 	}