xref: /openbmc/linux/arch/sparc/prom/bootstr_64.c (revision 275876e2)
1 /*
2  * bootstr.c:  Boot string/argument acquisition from the PROM.
3  *
4  * Copyright(C) 1995 David S. Miller (davem@caip.rutgers.edu)
5  * Copyright(C) 1996,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
6  */
7 
8 #include <linux/string.h>
9 #include <linux/init.h>
10 #include <asm/oplib.h>
11 
12 /* WARNING: The boot loader knows that these next three variables come one right
13  *          after another in the .data section.  Do not move this stuff into
14  *          the .bss section or it will break things.
15  */
16 
17 #define BARG_LEN  256
18 struct {
19 	int bootstr_len;
20 	int bootstr_valid;
21 	char bootstr_buf[BARG_LEN];
22 } bootstr_info = {
23 	.bootstr_len = BARG_LEN,
24 #ifdef CONFIG_CMDLINE
25 	.bootstr_valid = 1,
26 	.bootstr_buf = CONFIG_CMDLINE,
27 #endif
28 };
29 
30 char * __init
31 prom_getbootargs(void)
32 {
33 	/* This check saves us from a panic when bootfd patches args. */
34 	if (bootstr_info.bootstr_valid)
35 		return bootstr_info.bootstr_buf;
36 	prom_getstring(prom_chosen_node, "bootargs",
37 		       bootstr_info.bootstr_buf, BARG_LEN);
38 	bootstr_info.bootstr_valid = 1;
39 	return bootstr_info.bootstr_buf;
40 }
41