why just not boot your computers into efi mode? then the controller is in AHCI mode by default
mamo@xerxes:/etc/apt$ dmesg |grep AHCI [ 1.324986] ahci 0000:00:0b.0: AHCI 0001.0200 32 slots 6 ports 3 Gbps 0x3 impl SATA mode
why just not boot your computers into efi mode?
then the controller is in AHCI mode by default
mamo@xerxes: /etc/apt$ dmesg |grep AHCI
[ 1.324986] ahci 0000:00:0b.0: AHCI 0001.0200 32 slots 6 ports 3 Gbps 0x3 impl SATA mode