1NOTE: all the ABIs listed in this file are deprecated and will be removed after 2028. 2 3Here are the alternative ABIs: 4+------------------------------------+-----------------------------------------+ 5| Deprecated | Alternative | 6+------------------------------------+-----------------------------------------+ 7| /sys/kernel/kexec_loaded | /sys/kernel/kexec/loaded | 8+------------------------------------+-----------------------------------------+ 9| /sys/kernel/kexec_crash_loaded | /sys/kernel/kexec/crash_loaded | 10+------------------------------------+-----------------------------------------+ 11| /sys/kernel/kexec_crash_size | /sys/kernel/kexec/crash_size | 12+------------------------------------+-----------------------------------------+ 13| /sys/kernel/crash_elfcorehdr_size | /sys/kernel/kexec/crash_elfcorehdr_size | 14+------------------------------------+-----------------------------------------+ 15| /sys/kernel/kexec_crash_cma_ranges | /sys/kernel/kexec/crash_cma_ranges | 16+------------------------------------+-----------------------------------------+ 17 18 19What: /sys/kernel/kexec_loaded 20Date: Jun 2006 21Contact: kexec@lists.infradead.org 22Description: read only 23 Indicates whether a new kernel image has been loaded 24 into memory using the kexec system call. It shows 1 if 25 a kexec image is present and ready to boot, or 0 if none 26 is loaded. 27User: kexec tools, kdump service 28 29What: /sys/kernel/kexec_crash_loaded 30Date: Jun 2006 31Contact: kexec@lists.infradead.org 32Description: read only 33 Indicates whether a crash (kdump) kernel is currently 34 loaded into memory. It shows 1 if a crash kernel has been 35 successfully loaded for panic handling, or 0 if no crash 36 kernel is present. 37User: Kexec tools, Kdump service 38 39What: /sys/kernel/kexec_crash_size 40Date: Dec 2009 41Contact: kexec@lists.infradead.org 42Description: read/write 43 Shows the amount of memory reserved for loading the crash 44 (kdump) kernel. It reports the size, in bytes, of the 45 crash kernel area defined by the crashkernel= parameter. 46 This interface also allows reducing the crashkernel 47 reservation by writing a smaller value, and the reclaimed 48 space is added back to the system RAM. 49User: Kdump service 50 51What: /sys/kernel/crash_elfcorehdr_size 52Date: Aug 2023 53Contact: kexec@lists.infradead.org 54Description: read only 55 Indicates the preferred size of the memory buffer for the 56 ELF core header used by the crash (kdump) kernel. It defines 57 how much space is needed to hold metadata about the crashed 58 system, including CPU and memory information. This information 59 is used by the user space utility kexec to support updating the 60 in-kernel kdump image during hotplug operations. 61User: Kexec tools 62 63What: /sys/kernel/kexec_crash_cma_ranges 64Date: Nov 2025 65Contact: kexec@lists.infradead.org 66Description: read only 67 Provides information about the memory ranges reserved from 68 the Contiguous Memory Allocator (CMA) area that are allocated 69 to the crash (kdump) kernel. It lists the start and end physical 70 addresses of CMA regions assigned for crashkernel use. 71User: kdump service 72