KEXEC_LOAD(2) Linux Programmer's Manual KEXEC_LOAD(2)NAME
kexec_load - load a new kernel for later execution
SYNOPSIS
#include <linux/kexec.h>
long kexec_load(unsigned long entry, unsigned long nr_segments,
struct kexec_segment *segments, unsigned long flags);
Note: There is no glibc wrapper for this system call; see NOTES.
DESCRIPTION
The kexec_load() system call loads a new kernel that can be executed
later by reboot(2).
The flags argument is a mask whose high-order bits control the opera‐
tion of the call. The following values can be specified in flags:
KEXEC_ON_CRASH (since Linux 2.6.13)
Execute the new kernel automatically on a system crash.
KEXEC_PRESERVE_CONTEXT (since Linux 2.6.27)
Preserve the system hardware and software states before execut‐
ing the new kernel. This could be used for system suspend.
This flag is available only if the kernel was configured with
CONFIG_KEXEC_JUMP, and is effective only if nr_segments is
greater than 0.
The low-order bits of flags contain the architecture of the to-be-exe‐
cuted kernel. Specify (OR) the constant KEXEC_ARCH_DEFAULT to use the
current architecture, or one of the following architecture constants
KEXEC_ARCH_386, KEXEC_ARCH_X86_64, KEXEC_ARCH_PPC, KEXEC_ARCH_PPC64,
KEXEC_ARCH_IA_64, KEXEC_ARCH_ARM, KEXEC_ARCH_S390, KEXEC_ARCH_SH,
KEXEC_ARCH_MIPS, and KEXEC_ARCH_MIPS_LE. The architecture must be exe‐
cutable on the CPU of the system.
The entry argument is the physical entry address in the kernel image.
The nr_segments argument is the number of segments pointed to by the
segments pointer. The segments argument is an array of kexec_segment
structures which define the kernel layout:
struct kexec_segment {
void *buf; /* Buffer in user space */
size_t bufsz; /* Buffer length in user space */
void *mem; /* Physical address of kernel */
size_t memsz; /* Physical address length */
};
The kernel image defined by segments is copied from the calling process
into previously reserved memory.
RETURN VALUE
On success, kexec_load() returns 0. On error, -1 is returned and errno
is set to indicate the error.
ERRORS
EBUSY Another crash kernel is already being loaded or a crash kernel
is already in use.
EINVAL flags is invalid; or nr_segments is too large
EPERM The caller does not have the CAP_SYS_BOOT capability.
VERSIONS
The kexec_load() system call first appeared in Linux 2.6.13.
CONFORMING TO
This system call is Linux-specific.
NOTES
Currently, there is no glibc support for kexec_load(). Call it using
syscall(2).
The required constants are in the Linux kernel source file
linux/kexec.h, which is not currently exported to glibc. Therefore,
these constants must be defined manually.
This system call is available only if the kernel was configured with
CONFIG_KEXEC.
SEE ALSOreboot(2), syscall(2)COLOPHON
This page is part of release 3.53 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
Linux 2012-07-13 KEXEC_LOAD(2)