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 */ 11 unsigned 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 */ 20 unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX; 21 EXPORT_SYMBOL_GPL(elfcorehdr_addr); 22 23 /* 24 * stores the size of elf header of crash image 25 */ 26 unsigned 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 */ 34 static 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 } 46 early_param("elfcorehdr", setup_elfcorehdr); 47