#include "boot.h" /* * this doesn't yet use the crc */ typedef struct Uboot Uboot;struct Uboot {	Queue*	iq;	Block*	partial;	ulong	csum;	long	bno;	uchar	buf[64];	int	nleft;	int	ntimeout;}; static	Uboot	uboot;ulong	crc32(void *buf, int n, ulong crc); static voiduartbrecv(uchar *p, int n){	Uboot *ub;	Block *b; 	ub = &uboot;	if(n > 0 && ub->iq != nil){		b = iallocb(n);		memmove(b->wp, p, n);		b->wp += n;		qbwrite(ub->iq, b);	}} intuartinit(void){	return 1<<0;} Partition*setuartpart(int, char *s){	static Partition pp[1]; 	if(strcmp(s, "boot") != 0 && strcmp(s, "disk") != 0)		return 0;	pp[0].start = 0;	pp[0].end = 2*1024*1024;	strcpy(pp[0].name, "boot");	return pp;} longuartseek(int, long){	/* start the boot */	if(uboot.iq == nil)		uboot.iq = qopen(64*1024, 0, 0, 0);	if(uboot.partial){		freeb(uboot.partial);		uboot.partial = 0;	}	print("uart: start transmission\n");	uartsetboot(uartbrecv);	uboot.csum = ~0;	uboot.bno = 0;	uboot.nleft = 0;	uboot.ntimeout = 0;	return 0;} static longuartreadn(void *buf, int nb){	ulong start;	Uboot *ub;	int l;	Block *b;	uchar *p; 	p = buf;	ub = &uboot;	start = m->ticks;	while(nb > 0){		b = ub->partial;		ub->partial = nil;		if(b == nil){			ub->ntimeout = 0;			while((b = qget(ub->iq)) == 0){				if(TK2MS(m->ticks - start) >= 15*1000){					if(++ub->ntimeout >= 3){						print("uart: timeout\n");						return 0;					}					uartputs("n", 1);				}			}		}		l = BLEN(b);		if(l > nb)			l = nb;		memmove(p, b->rp, l);		b->rp += l;		if(b->rp >= b->wp)			freeb(b);		else			ub->partial = b;		nb -= l;		p += l;	}	return p-(uchar*)buf;} longuartread(int, void *buf, long n){	uchar *p;	int l;	static uchar lbuf[64]; 	p = buf;	if((l = uboot.nleft) > 0){		if(l > n)			l = n;		uboot.nleft -= l;		memmove(p, uboot.buf, l);		p += l;		n -= l;	}	while(n > 0){		l = uartreadn(lbuf, sizeof(lbuf));		if(l < sizeof(lbuf))			return 0;		if(l > n){			uboot.nleft = l-n;			memmove(uboot.buf, lbuf+n, uboot.nleft);			l = n;		}		memmove(p, lbuf, l);		n -= l;		p += l;		uboot.bno++;		uartputs("y", 1);	}	return p-(uchar*)buf;} /* * from Rob Warnock */static	ulong	crc32tab[256];	/* initialised on first call to crc32 */ enum {	CRC32POLY = 0x04c11db7     /* AUTODIN II, Ethernet, & FDDI */}; /* * Build auxiliary table for parallel byte-at-a-time CRC-32. */static voidinitcrc32(void){	int i, j;	ulong c; 	for(i = 0; i < 256; i++) {		for(c = i << 24, j = 8; j > 0; j--)			if(c & (1<<31))				c = (c<<1) ^ CRC32POLY;			else				c <<= 1;		crc32tab[i] = c;	}} ulongcrc32(void *buf, int n, ulong crc){	uchar *p; 	if(crc32tab[1] == 0)		initcrc32();	crc = ~crc;	for(p = buf; --n >= 0;)		crc = (crc << 8) ^ crc32tab[(crc >> 24) ^ *p++];	return ~crc;}