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 bit mask that controls the operation 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 executing 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  high-order bits (corresponding to the mask 0xffff0000) of flags contain the architec‐
       ture of the to-be-executed 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_68K,  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 executable 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 kernel imposes
       an (arbitrary) limit of 16 on the number of segments.  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 ALSO
       reboot(2), syscall(2)

COLOPHON
       This page is part of release 3.74 of the Linux man-pages project.  A  description  of  the
       project,  information  about  reporting  bugs, and the latest version of this page, can be
       found at http://www.kernel.org/doc/man-pages/.



Linux                                       2014-08-19                              KEXEC_LOAD(2)