xref: /linux/arch/mips/fw/arc/cmdline.c (revision 6a74422b9710e987c7d6b85a1ade7330b1e61626)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * cmdline.c: Kernel command line creation using ARCS argc/argv.
7  *
8  * Copyright (C) 1996 David S. Miller (davem@davemloft.net)
9  */
10 #include <linux/bug.h>
11 #include <linux/init.h>
12 #include <linux/kernel.h>
13 #include <linux/string.h>
14 
15 #include <asm/sgialib.h>
16 #include <asm/bootinfo.h>
17 
18 #undef DEBUG_CMDLINE
19 
20 /*
21  * A 32-bit ARC PROM pass arguments and environment as 32-bit pointer.
22  * These macro take care of sign extension.
23  */
24 #define prom_argv(index) ((char *) (long)argv[(index)])
25 
26 static char *ignored[] = {
27 	"ConsoleIn=",
28 	"ConsoleOut=",
29 	"SystemPartition=",
30 	"OSLoader=",
31 	"OSLoadPartition=",
32 	"OSLoadFilename=",
33 	"OSLoadOptions="
34 };
35 
36 static char *used_arc[][2] = {
37 	{ "OSLoadPartition=", "root=" },
38 	{ "OSLoadOptions=", "" }
39 };
40 
move_firmware_args(int argc,LONG * argv,char * cp)41 static char __init *move_firmware_args(int argc, LONG *argv, char *cp)
42 {
43 	char *s;
44 	int actr, i;
45 	size_t len;
46 
47 	actr = 1; /* Always ignore argv[0] */
48 
49 	while (actr < argc) {
50 		for (i = 0; i < ARRAY_SIZE(used_arc); i++) {
51 			len = strlen(used_arc[i][0]);
52 
53 			if (!strncmp(prom_argv(actr), used_arc[i][0], len)) {
54 			/* Ok, we want it. First append the replacement... */
55 				strcat(cp, used_arc[i][1]);
56 				cp += strlen(used_arc[i][1]);
57 				/* ... and now the argument */
58 				s = strchr(prom_argv(actr), '=');
59 				if (s) {
60 					s++;
61 					len = strlen(s);
62 					memcpy(cp, s, len + 1);
63 					cp += len;
64 				}
65 				*cp++ = ' ';
66 				break;
67 			}
68 		}
69 		actr++;
70 	}
71 
72 	return cp;
73 }
74 
prom_init_cmdline(int argc,LONG * argv)75 void __init prom_init_cmdline(int argc, LONG *argv)
76 {
77 	char *cp;
78 	int actr, i;
79 	size_t len;
80 
81 	actr = 1; /* Always ignore argv[0] */
82 
83 	cp = arcs_cmdline;
84 	/*
85 	 * Move ARC variables to the beginning to make sure they can be
86 	 * overridden by later arguments.
87 	 */
88 	cp = move_firmware_args(argc, argv, cp);
89 
90 	while (actr < argc) {
91 		for (i = 0; i < ARRAY_SIZE(ignored); i++) {
92 			len = strlen(ignored[i]);
93 			if (!strncmp(prom_argv(actr), ignored[i], len))
94 				goto pic_cont;
95 		}
96 
97 		/* Ok, we want it. */
98 		len = strlen(prom_argv(actr));
99 		memcpy(cp, prom_argv(actr), len + 1);
100 		cp += len;
101 		*cp++ = ' ';
102 
103 	pic_cont:
104 		actr++;
105 	}
106 
107 	if (cp != arcs_cmdline)		/* get rid of trailing space */
108 		--cp;
109 	*cp = '\0';
110 
111 #ifdef DEBUG_CMDLINE
112 	pr_debug("prom cmdline: %s\n", arcs_cmdline);
113 #endif
114 }
115