xref: /openbmc/linux/kernel/crash_dump.c (revision 842ed298)
1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/kernel.h>
3 #include <linux/crash_dump.h>
4 #include <linux/init.h>
5 #include <linux/errno.h>
6 #include <linux/export.h>
7 
8 /*
9  * stores the physical address of elf header of crash image
10  *
11  * Note: elfcorehdr_addr is not just limited to vmcore. It is also used by
12  * is_kdump_kernel() to determine if we are booting after a panic. Hence put
13  * it under CONFIG_CRASH_DUMP and not CONFIG_PROC_VMCORE.
14  */
15 unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
16 EXPORT_SYMBOL_GPL(elfcorehdr_addr);
17 
18 /*
19  * stores the size of elf header of crash image
20  */
21 unsigned long long elfcorehdr_size;
22 
23 /*
24  * elfcorehdr= specifies the location of elf core header stored by the crashed
25  * kernel. This option will be passed by kexec loader to the capture kernel.
26  *
27  * Syntax: elfcorehdr=[size[KMG]@]offset[KMG]
28  */
29 static int __init setup_elfcorehdr(char *arg)
30 {
31 	char *end;
32 	if (!arg)
33 		return -EINVAL;
34 	elfcorehdr_addr = memparse(arg, &end);
35 	if (*end == '@') {
36 		elfcorehdr_size = elfcorehdr_addr;
37 		elfcorehdr_addr = memparse(end + 1, &end);
38 	}
39 	return end > arg ? 0 : -EINVAL;
40 }
41 early_param("elfcorehdr", setup_elfcorehdr);
42