Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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