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); 48