kexec_load(2)
NAME
kexec_load - loads a new kernel image to memory
SYNOPSIS
#include <syscall.h>
#include <kexec.h>
long kexec_load(unsigned long entry, unsigned long nr_segments,
struct kexec_segment *segments, unsigned long flags);
DESCRIPTION
kexec_load loads the new kernel from the current address space. This
system call can only be used by root.
entry is a pointer to the entry point of newly loaded executable image.
This is the memory location where kernel will jump to and start executing instructions of newly loaded image.
nr_segments denotes the number of segments which will be passed to kexec_load. The value must not be greater than KEXEC_SEGMENT_MAX.
segments denotes a pointer to the first element of an array of
kexec_segment elements. A kexec_segment element contains the details of
a segment to be loaded in memory.
flags Sixteen most significant bits of the flag are used to communicate
the architecture information (KEXEC_ARCH_*). The values for various
architectures are same as defined by ELF specifications.
Lower sixteen bits have been reserved for miscellaneous information.
Currently only one bit is being used and rest fifteen have been
reserved for future use.
The least significant bit (KEXEC_ON_CRASH) can be set to inform the
kernel that the memory memory image being loaded is to be executed upon
a system crash and not regular boot. For regular boot, this bit is
cleared.
RETURN VALUE
On success, zero is returned. On error, nonzero value is
returned, and errno is set appropriately.
ERRORS
EPERM the calling process has not sufficient permissions (is not root).
EINVAL the flags argument contains an invalid combination of flags, or nr_segments is greater than KEXEC_SEGMENT_MAX.
ENOMEM there is not enough memory to store the kernel image.
EBUSY the memory location which should be written to is not available
now.
AVAILABILITY
- This syscall is implemented only since kernel 2.6.13