# cd /usr/ports/emulators/virtualbox-ose-additions/
# make install clean
查看安装说明：
root@ykla:/home/ykla # pkg info -D virtualbox-ose-additions
virtualbox-ose-additions-6.1.50.1401000:
On install:
VirtualBox Guest Additions are installed.
# VirtualBox 客户端增强功能已安装。
To enable and start the required services:
# sysrc vboxguest_enable="YES"
# sysrc vboxservice_enable="YES"
# 启用所需服务，使用 sysrc 添加开机启动项。
To start the services, restart the system.
# 要启动服务，请重启系统。
In some situations, a panic will occur when the kernel module loads.
Having no more than one virtual CPU might mitigate the issue.
# 某些情况下，加载内核模块时可能发生 panic。限制为单核虚拟 CPU 有可能缓解该问题。
For features such as window scaling and clipboard sharing, membership of
the wheel group is required. With username "jerry" as an example:
# pw groupmod wheel -m jerry
# 要启用窗口缩放、剪贴板共享等功能，用户需加入 wheel 组。
# 示例命令将用户 jerry 添加到 wheel 组。
The settings dialogue for FreeBSD guests encourages use of the VMSVGA
graphics controller. Whilst this might suit installations of FreeBSD
without a desktop environment (a common use case), it is not appropriate
where Guest Additions are installed.
# VirtualBox 会建议 FreeBSD 使用 VMSVGA 显卡控制器。
# 这对不含桌面的 FreeBSD 系统较为合适，但在已安装 Guest Additions 的环境下并不推荐。
Where Guest Additions are installed:
1. prefer VBoxSVGA
# 如果已安装 Guest Additions，应优先选择 VBoxSVGA 作为显卡控制器。
2. do not enable 3D acceleration (doing so will invisibly
lose the preference for VBoxSVGA)
# 不要启用 3D 加速，否则 VBoxSVGA 的设置会被暗中忽略。
You may ignore the yellow alert that encourages use of VMSVGA.
# 可以忽略提示使用 VMSVGA 的黄色警告信息。
