AHCI changes and FBS too

There’s been some updates to the AHCI driver.  Matthew Dillon outlined the changes, with the biggest one being support for FIS Based Switching.  FBS is the ability to send simultaneous streams of data to and from multiple drives on a port multiplier.  Support for it is rare and quirky, but it should significantly improve throughput on a compatible port multipler.  Read his writeup for details, including on how to back up your kernel.

EFI run-time ABI support in DragonFly

UEFI, which I casually sum up as the replacement for BIOS, has been seeing some support in DragonFly, but not within the installer.  Matthew Dillon and Sascha Wildner has ported over FreeBSD’s EFI ABI support, which I think means support for various EFI applications and features.  I haven’t booted a machine using UEFI in any significant way, so I don’t have a good explanation – but I am sure this is useful for people with new hardware.

Update: some explanation plus a note that it’s experimental and you could brick your machine.