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 22 /* 23 * stores the size of elf header of crash image 24 */ 25 unsigned long long elfcorehdr_size; 26 27 /* 28 * elfcorehdr= specifies the location of elf core header stored by the crashed 29 * kernel. This option will be passed by kexec loader to the capture kernel. 30 * 31 * Syntax: elfcorehdr=[size[KMG]@]offset[KMG] 32 */ 33 static int __init setup_elfcorehdr(char *arg) 34 { 35 char *end; 36 if (!arg) 37 return -EINVAL; 38 elfcorehdr_addr = memparse(arg, &end); 39 if (*end == '@') { 40 elfcorehdr_size = elfcorehdr_addr; 41 elfcorehdr_addr = memparse(end + 1, &end); 42 } 43 return end > arg ? 0 : -EINVAL; 44 } 45 early_param("elfcorehdr", setup_elfcorehdr); 46