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