1What: /sys/kernel/kexec_loaded 2Date: Jun 2006 3Contact: kexec@lists.infradead.org 4Description: read only 5 Indicates whether a new kernel image has been loaded 6 into memory using the kexec system call. It shows 1 if 7 a kexec image is present and ready to boot, or 0 if none 8 is loaded. 9User: kexec tools, kdump service 10 11What: /sys/kernel/kexec_crash_loaded 12Date: Jun 2006 13Contact: kexec@lists.infradead.org 14Description: read only 15 Indicates whether a crash (kdump) kernel is currently 16 loaded into memory. It shows 1 if a crash kernel has been 17 successfully loaded for panic handling, or 0 if no crash 18 kernel is present. 19User: Kexec tools, Kdump service 20 21What: /sys/kernel/kexec_crash_size 22Date: Dec 2009 23Contact: kexec@lists.infradead.org 24Description: read/write 25 Shows the amount of memory reserved for loading the crash 26 (kdump) kernel. It reports the size, in bytes, of the 27 crash kernel area defined by the crashkernel= parameter. 28 This interface also allows reducing the crashkernel 29 reservation by writing a smaller value, and the reclaimed 30 space is added back to the system RAM. 31User: Kdump service 32 33What: /sys/kernel/crash_elfcorehdr_size 34Date: Aug 2023 35Contact: kexec@lists.infradead.org 36Description: read only 37 Indicates the preferred size of the memory buffer for the 38 ELF core header used by the crash (kdump) kernel. It defines 39 how much space is needed to hold metadata about the crashed 40 system, including CPU and memory information. This information 41 is used by the user space utility kexec to support updating the 42 in-kernel kdump image during hotplug operations. 43User: Kexec tools 44 45What: /sys/kernel/kexec_crash_cma_ranges 46Date: Nov 2025 47Contact: kexec@lists.infradead.org 48Description: read only 49 Provides information about the memory ranges reserved from 50 the Contiguous Memory Allocator (CMA) area that are allocated 51 to the crash (kdump) kernel. It lists the start and end physical 52 addresses of CMA regions assigned for crashkernel use. 53User: kdump service 54