1/*
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 <linux/init.h>
10
11#define BARG_LEN  256
12static char barg_buf[BARG_LEN] = { 0 };
13static char fetched __initdata = 0;
14
15char * __init
16prom_getbootargs(void)
17{
18	int iter;
19	char *cp, *arg;
20
21	/* This check saves us from a panic when bootfd patches args. */
22	if (fetched) {
23		return barg_buf;
24	}
25
26	switch(prom_vers) {
27	case PROM_V0:
28		cp = barg_buf;
29		/* Start from 1 and go over fd(0,0,0)kernel */
30		for(iter = 1; iter < 8; iter++) {
31			arg = (*(romvec->pv_v0bootargs))->argv[iter];
32			if (arg == NULL)
33				break;
34			while(*arg != 0) {
35				/* Leave place for space and null. */
36				if(cp >= barg_buf + BARG_LEN-2){
37					/* We might issue a warning here. */
38					break;
39				}
40				*cp++ = *arg++;
41			}
42			*cp++ = ' ';
43		}
44		*cp = 0;
45		break;
46	case PROM_V2:
47	case PROM_V3:
48		/*
49		 * V3 PROM cannot supply as with more than 128 bytes
50		 * of an argument. But a smart bootstrap loader can.
51		 */
52		strlcpy(barg_buf, *romvec->pv_v2bootargs.bootargs, sizeof(barg_buf));
53		break;
54	default:
55		break;
56	}
57
58	fetched = 1;
59	return barg_buf;
60}
61