xref: /openbmc/linux/arch/sparc/prom/bootstr_64.c (revision 9cfc5c90)
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 /* We limit BARG_LEN to 1024 because this is the size of the
18  * 'barg_out' command line buffer in the SILO bootloader.
19  */
20 #define BARG_LEN 1024
21 struct {
22 	int bootstr_len;
23 	int bootstr_valid;
24 	char bootstr_buf[BARG_LEN];
25 } bootstr_info = {
26 	.bootstr_len = BARG_LEN,
27 #ifdef CONFIG_CMDLINE
28 	.bootstr_valid = 1,
29 	.bootstr_buf = CONFIG_CMDLINE,
30 #endif
31 };
32 
33 char * __init
34 prom_getbootargs(void)
35 {
36 	/* This check saves us from a panic when bootfd patches args. */
37 	if (bootstr_info.bootstr_valid)
38 		return bootstr_info.bootstr_buf;
39 	prom_getstring(prom_chosen_node, "bootargs",
40 		       bootstr_info.bootstr_buf, BARG_LEN);
41 	bootstr_info.bootstr_valid = 1;
42 	return bootstr_info.bootstr_buf;
43 }
44