#include "u.h"#include "lib.h"#include "mem.h"#include "dat.h"#include "fns.h"#include "io.h" static intaddbytes(char **dbuf, char *edbuf, char **sbuf, char *esbuf){	int n; 	n = edbuf - *dbuf;	if(n <= 0)		return 0;	if(n > esbuf - *sbuf)		n = esbuf - *sbuf;	if(n <= 0)		return -1; 	memmove(*dbuf, *sbuf, n);	*sbuf += n;	*dbuf += n;	return edbuf - *dbuf;} extern void origin(void); intbootpass(Boot *b, void *vbuf, int nbuf){	char *buf, *ebuf, *p, *q;	ulong size; 	if(b->state == FAILED)		return FAIL; 	if(nbuf == 0)		goto Endofinput; 	buf = vbuf;	ebuf = buf+nbuf;	while(addbytes(&b->wp, b->ep, &buf, ebuf) == 0) {		switch(b->state) {		case INIT9LOAD:			b->state = READ9LOAD;			b->bp = (char*)0x10000;			b->wp = b->bp;			b->ep = b->bp + 256*1024;			break; 		case READ9LOAD:			return ENOUGH; 		default:			panic("bootstate");		}	}	return MORE;  Endofinput:	/* end of input */	print("\n");	switch(b->state) {	case INIT9LOAD:		print("premature EOF\n");		b->state = FAILED;		return FAIL;		case READ9LOAD:		size = b->wp - b->bp;		if(memcmp(b->bp, origin, 16) != 0) {			print("beginning of file does not look right\n");			b->state = FAILED;			return FAIL;		}		if(size < 32*1024 || size > 256*1024) {			print("got %lud byte loader; not likely\n", size);			b->state = FAILED;			return FAIL;		} 		p = b->bp;		q = b->wp;		if(q - p > 10000)	/* don't search much past l.s */			q = p+10000; 		/*		 * The string `JUMP' appears right before		 * tokzero, which is where we want to jump.		 */		for(; p<q; p++) {			if(strncmp(p, "JUMP", 4) == 0) {				p += 4;				warp9((ulong)p);			}		}		print("could not find jump destination\n");		b->state = FAILED;		return FAIL; 	default:		panic("bootdone");	}	b->state = FAILED;	return FAIL;}