summaryrefslogtreecommitdiff
path: root/Documentation/ABI/testing/sysfs-kernel-kexec-kdump
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/ABI/testing/sysfs-kernel-kexec-kdump')
-rw-r--r--Documentation/ABI/testing/sysfs-kernel-kexec-kdump61
1 files changed, 61 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-kernel-kexec-kdump b/Documentation/ABI/testing/sysfs-kernel-kexec-kdump
new file mode 100644
index 000000000000..f59051b5d96d
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-kernel-kexec-kdump
@@ -0,0 +1,61 @@
+What: /sys/kernel/kexec/*
+Date: Nov 2025
+Contact: kexec@lists.infradead.org
+Description:
+ The /sys/kernel/kexec/* directory contains sysfs files
+ that provide information about the configuration status
+ of kexec and kdump.
+
+What: /sys/kernel/kexec/loaded
+Date: Nov 2025
+Contact: kexec@lists.infradead.org
+Description: read only
+ Indicates whether a new kernel image has been loaded
+ into memory using the kexec system call. It shows 1 if
+ a kexec image is present and ready to boot, or 0 if none
+ is loaded.
+User: kexec tools, kdump service
+
+What: /sys/kernel/kexec/crash_loaded
+Date: Nov 2025
+Contact: kexec@lists.infradead.org
+Description: read only
+ Indicates whether a crash (kdump) kernel is currently
+ loaded into memory. It shows 1 if a crash kernel has been
+ successfully loaded for panic handling, or 0 if no crash
+ kernel is present.
+User: Kexec tools, Kdump service
+
+What: /sys/kernel/kexec/crash_size
+Date: Nov 2025
+Contact: kexec@lists.infradead.org
+Description: read/write
+ Shows the amount of memory reserved for loading the crash
+ (kdump) kernel. It reports the size, in bytes, of the
+ crash kernel area defined by the crashkernel= parameter.
+ This interface also allows reducing the crashkernel
+ reservation by writing a smaller value, and the reclaimed
+ space is added back to the system RAM.
+User: Kdump service
+
+What: /sys/kernel/kexec/crash_elfcorehdr_size
+Date: Nov 2025
+Contact: kexec@lists.infradead.org
+Description: read only
+ Indicates the preferred size of the memory buffer for the
+ ELF core header used by the crash (kdump) kernel. It defines
+ how much space is needed to hold metadata about the crashed
+ system, including CPU and memory information. This information
+ is used by the user space utility kexec to support updating the
+ in-kernel kdump image during hotplug operations.
+User: Kexec tools
+
+What: /sys/kernel/kexec/crash_cma_ranges
+Date: Nov 2025
+Contact: kexec@lists.infradead.org
+Description: read only
+ Provides information about the memory ranges reserved from
+ the Contiguous Memory Allocator (CMA) area that are allocated
+ to the crash (kdump) kernel. It lists the start and end physical
+ addresses of CMA regions assigned for crashkernel use.
+User: kdump service