It is easy as it says.

• As root mkdir /usr/src and then chown it to a standard user
• Get syssrc.tgz from the appropriate sources directory.
• Extract to root directory since the archive already contains the /usr/src paths: tar -xzf syssrc.tgz -C /

The CONF file is self explanatory, I just commented out any lines mentioning fdc, midi or mpu (since that is where I was experiencing issues) and then added options ACPI_BLACKLIST_YEAR=1 in to force it to load since I’d forgotten to update the BIOS.

There is no need for build.sh (which is in src.tgz) if building for the same architecture, apparently.

Took quite some time on the brick, enough to cycle to the shops and mow a lawn, but it did build.