1 /* $Id: bootstr.c,v 1.20 2000/02/08 20:24:23 davem Exp $
2  * bootstr.c:  Boot string/argument acquisition from the PROM.
3  *
4  * Copyright(C) 1995 David S. Miller (davem@caip.rutgers.edu)
5  */
6 
7 #include <linux/string.h>
8 #include <asm/oplib.h>
9 #include <asm/sun4prom.h>
10 #include <linux/init.h>
11 
12 #define BARG_LEN  256
13 static char barg_buf[BARG_LEN] = { 0 };
14 static char fetched __initdata = 0;
15 
16 extern linux_sun4_romvec *sun4_romvec;
17 
18 char * __init
prom_getbootargs(void)19 prom_getbootargs(void)
20 {
21 	int iter;
22 	char *cp, *arg;
23 
24 	/* This check saves us from a panic when bootfd patches args. */
25 	if (fetched) {
26 		return barg_buf;
27 	}
28 
29 	switch(prom_vers) {
30 	case PROM_V0:
31 	case PROM_SUN4:
32 		cp = barg_buf;
33 		/* Start from 1 and go over fd(0,0,0)kernel */
34 		for(iter = 1; iter < 8; iter++) {
35 			arg = (*(romvec->pv_v0bootargs))->argv[iter];
36 			if(arg == 0) break;
37 			while(*arg != 0) {
38 				/* Leave place for space and null. */
39 				if(cp >= barg_buf + BARG_LEN-2){
40 					/* We might issue a warning here. */
41 					break;
42 				}
43 				*cp++ = *arg++;
44 			}
45 			*cp++ = ' ';
46 		}
47 		*cp = 0;
48 		break;
49 	case PROM_V2:
50 	case PROM_V3:
51 		/*
52 		 * V3 PROM cannot supply as with more than 128 bytes
53 		 * of an argument. But a smart bootstrap loader can.
54 		 */
55 		strncpy(barg_buf, *romvec->pv_v2bootargs.bootargs, BARG_LEN-1);
56 		break;
57 	default:
58 		break;
59 	}
60 
61 	fetched = 1;
62 	return barg_buf;
63 }
64