kexec_load -加載新的內核映像到內存

內容簡介

#include <syscall.h>
#include <kexec.h>

long kexec_load(unsigned long entry**, unsigned long** nr_segments**,** **  
                            struct kexec_segment *flags);**

描述

kexec_load 加載從當前地址空間中的新內核。這個系統調用只能用於由root。

條目是一個指向新加載的可執行映像的入口點。這是內核將跳轉到並開始執行新加載的圖像的指令的存儲器位置。

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_segmentelements. 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.

返回值

On success, zero is returned. On error, nonzero value is returned, and  errno is set appropriately.

錯誤

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.

可用性

This syscall is implemented only since kernel 2.6.1