NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | VERSIONS | CONFORMING TO | NOTES | SEE ALSO | COLOPHON

KEXEC_LOAD(2)             Linux Programmer's Manual            KEXEC_LOAD(2)

NAME         top

       kexec_load - load a new kernel for later execution

SYNOPSIS         top

       #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         top

       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 architecture 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         top

       On success, kexec_load() returns 0.  On error, -1 is returned and
       errno is set to indicate the error.

ERRORS         top

       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         top

       The kexec_load() system call first appeared in Linux 2.6.13.

CONFORMING TO         top

       This system call is Linux-specific.

NOTES         top

       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         top

       reboot(2), syscall(2)

COLOPHON         top

       This page is part of release 3.75 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)