kernel 调用uefi的run time service 关机

当上层调用reboot命令时，就会调用到arch/arm64/kernel/process.c 中的SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,void __user *, arg)
{
    struct pid_namespace *pid_ns = task_active_pid_ns(current);
    char buffer[256];
    int ret = 0;

    

    mutex_lock(&reboot_mutex);
    switch (cmd) {
    case LINUX_REBOOT_CMD_RESTART:
        kernel_restart(NULL);
        break;
    case LINUX_REBOOT_CMD_POWER_OFF:
        kernel_power_off();
        do_exit(0);
        break;


}
我们重点开看请参数是LINUX_REBOOT_CMD_RESTART时，会调用kernel_restart->machine_restart
void machine_restart(char *cmd)
{