I have an old PC with an ASUS P5K for running DragonFly BSD.
Apparently ASUS disabled AHCI due to licensing issues. I can't find any proof for this other than the AHCI option not being available in the BIOS.
Luckily someone modified the latest BIOS and made it available at bios-mods.com. The following steps worked for me:
- Extract the archive and rename
- Get a USB drive and create a small FAT32 partition on it.
P5K-1201.ROMto the drive.
- Boot target computer, enter the BIOS, insert USB drive.
- Go to the TOOLS tab then start EZ Flash 2.
- The ROM file should be someone on the detected drives.
- Run update, EZ Flash reboots computer.
- After reboot go to BIOS and set ACHI in the SATA configuration.