1#include <linux/kernel.h>
2#include <linux/crash_dump.h>
3#include <linux/init.h>
4#include <linux/errno.h>
5#include <linux/export.h>
6
7/*
8 * If we have booted due to a crash, max_pfn will be a very low value. We need
9 * to know the amount of memory that the previous kernel used.
10 */
11unsigned long saved_max_pfn;
12
13/*
14 * stores the physical address of elf header of crash image
15 *
16 * Note: elfcorehdr_addr is not just limited to vmcore. It is also used by
17 * is_kdump_kernel() to determine if we are booting after a panic. Hence put
18 * it under CONFIG_CRASH_DUMP and not CONFIG_PROC_VMCORE.
19 */
20unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
21EXPORT_SYMBOL_GPL(elfcorehdr_addr);
22
23/*
24 * stores the size of elf header of crash image
25 */
26unsigned long long elfcorehdr_size;
27
28/*
29 * elfcorehdr= specifies the location of elf core header stored by the crashed
30 * kernel. This option will be passed by kexec loader to the capture kernel.
31 *
32 * Syntax: elfcorehdr=[size[KMG]@]offset[KMG]
33 */
34static int __init setup_elfcorehdr(char *arg)
35{
36 char *end;
37 if (!arg)
38 return -EINVAL;
39 elfcorehdr_addr = memparse(arg, &end);
40 if (*end == '@') {
41 elfcorehdr_size = elfcorehdr_addr;
42 elfcorehdr_addr = memparse(end + 1, &end);
43 }
44 return end > arg ? 0 : -EINVAL;
45}
46early_param("elfcorehdr", setup_elfcorehdr);
47