kexec_load(2)

1KEXEC_LOAD(2)              Linux Programmer's Manual             KEXEC_LOAD(2)
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NAME

6       kexec_load - load a new kernel for later execution
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SYNOPSIS

9       #include <linux/kexec.h>
10       long kexec_load(unsigned long entry, unsigned long nr_segments,
11                       struct kexec_segment *segments, unsigned long flags);
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13       Note: There is no glibc wrapper for this system call; see NOTES.
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DESCRIPTION

16       The  kexec_load()  system  call loads a new kernel that can be executed
17       later by reboot(2).
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19       The flags argument is a mask whose high-order bits control  the  opera‐
20       tion of the call.  The following values can be specified in flags:
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22       KEXEC_ON_CRASH (since Linux 2.6.13)
23              Execute the new kernel automatically on a system crash.
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25       KEXEC_PRESERVE_CONTEXT (since Linux 2.6.27)
26              Preserve  the system hardware and software states before execut‐
27              ing the new kernel.  This could  be  used  for  system  suspend.
28              This  flag  is  available only if the kernel was configured with
29              CONFIG_KEXEC_JUMP, and  is  effective  only  if  nr_segments  is
30              greater than 0.
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32       The  low-order bits of flags contain the architecture of the to-be-exe‐
33       cuted kernel.  Specify (OR) the constant KEXEC_ARCH_DEFAULT to use  the
34       current  architecture,  or  one of the following architecture constants
35       KEXEC_ARCH_386,  KEXEC_ARCH_X86_64,  KEXEC_ARCH_PPC,  KEXEC_ARCH_PPC64,
36       KEXEC_ARCH_IA_64,   KEXEC_ARCH_ARM,   KEXEC_ARCH_S390,   KEXEC_ARCH_SH,
37       KEXEC_ARCH_MIPS, and KEXEC_ARCH_MIPS_LE.  The architecture must be exe‐
38       cutable on the CPU of the system.
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40       The  entry  argument is the physical entry address in the kernel image.
41       The nr_segments argument is the number of segments pointed  to  by  the
42       segments  pointer.   The segments argument is an array of kexec_segment
43       structures which define the kernel layout:
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45           struct kexec_segment {
46               void   *buf;        /* Buffer in user space */
47               size_t  bufsz;      /* Buffer length in user space */
48               void   *mem;        /* Physical address of kernel */
49               size_t  memsz;      /* Physical address length */
50           };
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52       The kernel image defined by segments is copied from the calling process
53       into previously reserved memory.
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RETURN VALUE

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

60       EBUSY  Another crash kernel is already being loaded or a  crash  kernel
61              is already in use.
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63       EINVAL flags is invalid; or nr_segments is too large
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65       EPERM  The caller does not have the CAP_SYS_BOOT capability.
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VERSIONS

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

71       This system call is Linux-specific.
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NOTES

74       Currently,  there  is no glibc support for kexec_load().  Call it using
75       syscall(2).
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77       The  required  constants  are  in  the   Linux   kernel   source   file
78       linux/kexec.h,  which  is  not currently exported to glibc.  Therefore,
79       these constants must be defined manually.
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81       This system call is available only if the kernel  was  configured  with
82       CONFIG_KEXEC.
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COLOPHON

88       This  page  is  part of release 3.53 of the Linux man-pages project.  A
89       description of the project, and information about reporting  bugs,  can
90       be found at http://www.kernel.org/doc/man-pages/.
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94Linux                             2012-07-13                     KEXEC_LOAD(2)