1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * bootstr.c: Boot string/argument acquisition from the PROM. |
4 | * |
5 | * Copyright(C) 1995 David S. Miller (davem@caip.rutgers.edu) |
6 | */ |
7 | |
8 | #include <linux/string.h> |
9 | #include <asm/oplib.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 | char * __init |
17 | prom_getbootargs(void) |
18 | { |
19 | int iter; |
20 | char *cp, *arg; |
21 | |
22 | /* This check saves us from a panic when bootfd patches args. */ |
23 | if (fetched) { |
24 | return barg_buf; |
25 | } |
26 | |
27 | switch (prom_vers) { |
28 | case PROM_V0: |
29 | cp = barg_buf; |
30 | /* Start from 1 and go over fd(0,0,0)kernel */ |
31 | for (iter = 1; iter < 8; iter++) { |
32 | arg = (*(romvec->pv_v0bootargs))->argv[iter]; |
33 | if (arg == NULL) |
34 | break; |
35 | while (*arg != 0) { |
36 | /* Leave place for space and null. */ |
37 | if (cp >= barg_buf + BARG_LEN - 2) |
38 | /* We might issue a warning here. */ |
39 | break; |
40 | *cp++ = *arg++; |
41 | } |
42 | *cp++ = ' '; |
43 | if (cp >= barg_buf + BARG_LEN - 1) |
44 | /* We might issue a warning here. */ |
45 | break; |
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 | strscpy(barg_buf, *romvec->pv_v2bootargs.bootargs, sizeof(barg_buf)); |
56 | break; |
57 | default: |
58 | break; |
59 | } |
60 | |
61 | fetched = 1; |
62 | return barg_buf; |
63 | } |
64 | |