freebsd

This command can be used:
ffmpeg -video_size 1920x1080 -framerate 25 -f x11grab -i :0.0+0,0 -f oss -i /dev/dsp5.0 -filter:a "asetpts=N/SR/TB" output.mp4
Command above assumes that microphone is at /dev/dsp5.0 (you can check that with cat /dev/sndstat), and you can adjust microphone volume with mixer -f /dev/mixer5 mic 100.

Use dmidecode (It is in /usr/ports/sysutils/dmidecode).

Simply load urndis module
# kldload urndis

Connect mobile phone using USB cable with FreeBSD machine. On phone choose "USB tethering" for USB. On FreeBSD machine there should appear new network device ue0 or something similarly named. You can use for example dhclient ue0 to pull IP address for that device and then you can configure routing to use that device as default route.

Steps:

To disable bitmap fonts in X create symbolic link to ../conf.avail/70-no-bitmaps.conf in /usr/local/etc/fonts/conf.d
# cd /usr/local/etc/fonts/conf.d
# ln -s ../conf.avail/70-no-bitmaps.conf


Some instructions can be found at FreeBSD wiki and FreeBSD forums

If X doesn't start with message similar to "Cannot run in framebuffer mode. Please specify busIDs" and you are booting your system using UEFI you should install package drm-kmod, and make sure to load appropriate module before starting X (for example i915kms.ko), but beware that after installing package modules with same names will be present in both /boot/kernel and /boot/modules, so it is necessary to give full path to module to load (for example kldload /boot/modules/i915kms.ko).

Just non-obvious steps listed (with things to replace in uppercase), follow their installation instructions for general setup

It can be done using sysctl hw.snd.default_unit. Before that it is good idea to check contents of /dev/sndstat file.

If you have to set native resolution on system console (if for example you have to run scfb driver for X), first check resolutions supported by UEFI - escape to loader prompt when booting OS and type:
mode
That should list all textual modes recognized by loader (alternatively you can also try gop list or uga list, but saving gop mode setting using following method won't work (I don't know about uga since my computer doesn't support it)). After this you can set mode you want to use using
mode NUMBER