xref: /openbmc/linux/arch/mips/fw/arc/cmdline.c (revision 7b16831d)
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 
46 	actr = 1; /* Always ignore argv[0] */
47 
48 	while (actr < argc) {
49 		for(i = 0; i < ARRAY_SIZE(used_arc); i++) {
50 			int len = strlen(used_arc[i][0]);
51 
52 			if (!strncmp(prom_argv(actr), used_arc[i][0], len)) {
53 			/* Ok, we want it. First append the replacement... */
54 				strcat(cp, used_arc[i][1]);
55 				cp += strlen(used_arc[i][1]);
56 				/* ... and now the argument */
57 				s = strchr(prom_argv(actr), '=');
58 				if (s) {
59 					s++;
60 					strcpy(cp, s);
61 					cp += strlen(s);
62 				}
63 				*cp++ = ' ';
64 				break;
65 			}
66 		}
67 		actr++;
68 	}
69 
70 	return cp;
71 }
72 
prom_init_cmdline(int argc,LONG * argv)73 void __init prom_init_cmdline(int argc, LONG *argv)
74 {
75 	char *cp;
76 	int actr, i;
77 
78 	actr = 1; /* Always ignore argv[0] */
79 
80 	cp = arcs_cmdline;
81 	/*
82 	 * Move ARC variables to the beginning to make sure they can be
83 	 * overridden by later arguments.
84 	 */
85 	cp = move_firmware_args(argc, argv, cp);
86 
87 	while (actr < argc) {
88 		for (i = 0; i < ARRAY_SIZE(ignored); i++) {
89 			int len = strlen(ignored[i]);
90 
91 			if (!strncmp(prom_argv(actr), ignored[i], len))
92 				goto pic_cont;
93 		}
94 		/* Ok, we want it. */
95 		strcpy(cp, prom_argv(actr));
96 		cp += strlen(prom_argv(actr));
97 		*cp++ = ' ';
98 
99 	pic_cont:
100 		actr++;
101 	}
102 
103 	if (cp != arcs_cmdline)		/* get rid of trailing space */
104 		--cp;
105 	*cp = '\0';
106 
107 #ifdef DEBUG_CMDLINE
108 	printk(KERN_DEBUG "prom cmdline: %s\n", arcs_cmdline);
109 #endif
110 }
111