enum {	DQ7 = I(0x80),	DQ6 = I(0x40),	DQ5 = I(0x20),	DQ4 = I(0x10),	DQ3 = I(0x08),	DQ2 = I(0x04),	DQ1 = I(0x02),	DQ0 = I(0x01),}; /* * intel algorithm */ enum {	ReadID = I(0x90),	ClearStatus = I(0x50),	ReadStatus = I(0x70),	Program = I(0x40),	BlockErase = I(0x20),	Confirm = I(0xD0),}; #define	DPRINT	if(0)print#define	EPRINT	if(1)print static char*intelwait(Flash *f, void *p, ulong ticks){	ulong csr, mask; 	ticks += m->ticks+1;	mask = f->cmask;	for(;;){		if(f->width == 2)			csr = *(ushort*)p;		else			csr = *(ulong*)p;		if((csr & mask) == (DQ7 & mask))			break;		sched();		if(m->ticks >= ticks)			return "flash write timed out";	}	if(csr & (DQ5|DQ4|DQ3|DQ1)){		EPRINT("flash: error: %8.8lux %8.8lux\n", p, csr);		if(csr & DQ1)			return "flash block locked";		if(csr & DQ3)			return "low flash programming voltage";		return Eio;	}	return nil;} static intintelerase(Flash *f, Flashregion *r, ulong addr){	int s;	char *e; 	DPRINT("flash: erase zone %8.8lux\n", addr);	if(addr & (r->erasesize-1))		return -1;	/* bad zone */	if(f->width == 2){		ushort *p = (ushort*)((ulong)f->addr + addr);		s = splhi();		*p = BlockErase & f->cmask;		*p = Confirm & f->cmask;		splx(s);		e = intelwait(f, p, MS2TK(8*1000));		*p = ClearStatus & f->cmask;		*p = ReadArray & f->cmask;	}else{		ulong *p = (ulong*)((ulong)f->addr + addr);		s = splhi();		*p = BlockErase & f->cmask;		*p = Confirm & f->cmask;		splx(s);		e = intelwait(f, p, MS2TK(8*1000));		*p = ClearStatus & f->cmask;		*p = ReadArray & f->cmask;	}	if(e != nil)		error(e);	return 0;} static intintelwrite2(Flash *f, ulong offset, void *buf, long n){	ushort *a, *v;	ulong w;	int s;	char *e; 	if(((ulong)f->addr|offset|n)&(f->width-1))		return -1;	a = (ushort*)((ulong)f->addr + offset);	n /= f->width;	v = buf;	if(waserror()){		*a = ClearStatus & f->cmask;		*a = ReadArray & f->cmask;		nexterror();	}	for(; --n >= 0; v++, a++){		w = *a;		DPRINT("flash: write %p %#ulx -> %#lux\n", a, w, (ulong)*v);		if(w == *v)			continue;	/* already set */		if(~w & *v)			error("flash not erased");		s = splhi();		*a = Program & f->cmask;	/* program */		*a = *v;		splx(s);		microdelay(8);		e = intelwait(f, a, 5);		*a = ClearStatus & f->cmask;		*a = ReadArray & f->cmask;		if(e != nil)			error(e);		w = *a;		if(w != *v){			EPRINT("flash: write %p %#8.8lux -> %#8.8lux failed\n", a, w, (ulong)*v);			error(Eio);		}	}	poperror();	return 0;} static intintelwrite4(Flash *f, ulong offset, void *buf, long n){	ulong *a, *v;	ulong w;	int s;	char *e; 	if(((ulong)f->addr|offset|n)&(f->width-1))		return -1;	a = (ulong*)((ulong)f->addr + offset);	n /= f->width;	v = buf;	if(waserror()){		*a = ClearStatus & f->cmask;		*a = ReadArray & f->cmask;		nexterror();	}	for(; --n >= 0; v++, a++){		w = *a;		DPRINT("flash: write %p %#ulx -> %#lux\n", a, w, (ulong)*v);		if(w == *v)			continue;	/* already set */		if(~w & *v)			error("flash not erased");		s = splhi();		*a = Program;	/* program */		*a = *v;		splx(s);		microdelay(8);		e = intelwait(f, a, 5);		*a = ClearStatus & f->cmask;		*a = ReadArray & f->cmask;		if(e != nil)			error(e);		w = *a;		if(w != *v){			EPRINT("flash: write %p %#8.8lux -> %#8.8lux failed\n", a, w, *v);			error(Eio);		}	}	poperror();	return 0;}