1. 风扇开机自启设置
切换到 root 用户
sudo su
修改风扇pwm调速文件权限
chmod 777 /sys/devices/pwm-fan/target_pwm
修改系统外设配置文件，并添加风扇开机启动任务：
vim /lib/systemd/system/rc-local.service
注意：
1.如不知道该文件路径，可以通过搜索rc-local.service来查看；
2.vim编辑器使用：进入vim编辑器后，按i键进入编辑模式，对内容进行编辑，按esc退出编辑模式，退出编辑模式情况下，输入：wq，可保存并退出vim编辑器。
修改前内容：
# SPDX-License-Identifier: LGPL-2.1+
#
# This file is part of systemd.
#
# systemd is free software; you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.# This unit gets pulled automatically into multi-user.target by
# systemd-rc-local-generator if /etc/rc.local is executable.
[Unit]
Description=/etc/rc.local Compatibility
Documentation=man:systemd-rc-local-generator(8)
ConditionFileIsExecutable=/etc/rc.local
After=network.target[Service]
Type=forking
ExecStart=/etc/rc.local start
TimeoutSec=0
RemainAfterExit=yes
GuessMainPID=no
在后面添加install区块：
[Install]
WantedBy=multi-user.target
Alias=rc-local.service
修改后内容：
# SPDX-License-Identifier: LGPL-2.1+
#
# This file is part of systemd.
#
# systemd is free software; you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.# This unit gets pulled automatically into multi-user.target by
# systemd-rc-local-generator if /etc/rc.local is executable.
[Unit]
Description=/etc/rc.local Compatibility
Documentation=man:systemd-rc-local-generator(8)
ConditionFileIsExecutable=/etc/rc.local
After=network.target[Service]
Type=forking
ExecStart=/etc/rc.local start
TimeoutSec=0
RemainAfterExit=yes
GuessMainPID=no[Install]
WantedBy=multi-user.target
Alias=rc-local.service
新建任务文件：
vim /etc/rc.local
添加风扇自启任务（其中echo后的值为风扇转速，范围为0-250）：
#!/bin/bash -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.sleep 30
echo "200" > /sys/devices/pwm-fan/target_pwmexit 0
使rc-local服务自动启动
systemctl enable rc-local #这条语句就是创建一个超链接，在系统启动服务程序中.
给rc.local文件赋予可执行权限:
chmod +x /etc/rc.local
先执行如下命令,启动服务并检查状态
systemctl daemon-reload #重新加载
systemctl stop rc-local.service #停止rc-local.service服务
systemctl start rc-local.service #启动rc-local.service服务
systemctl status rc-local.service #检查服务状态
如果上面的命令不报错了,那说明设置成功了,然后就可以重启看下效果
2. 直接开启风扇（重启无效）
用vim编辑器修改（范围：0~250）：
vim /sys/devices/pwm-fan/target_pwm
终端直接修改：
sudo sh -c "echo 150 > /sys/devices/pwm-fan/target_pwm"
第一次写博客，有不足之处请批评指出。
参考资料：
https://blog.csdn.net/u013171226/article/details/107680325
http://lnmp.ailinux.net/systemctl
