FreeBSD 4.x-RELEASE on the intel 875 or 865-series chipsets

[Dan Strick]

On Fri, 12 Dec 2003, Brian Costello wrote:
>>>
> I posted a question about FreeBSD on Shuttle hardware yesterday, but figured
> my subject line might've been too vague for people to recognize.  Anyway, I
> am wondering if FreeBSD 4.x will work with drives hooked into either of
> those chipsets' onboard SATA.  Specifically, the harddrives are western
> digital 10,000rpm serial ata drives, and I wonder if FreeBSD can handle
> booting off of them.  I imagine that FreeBSD doesn't support serial ata
> natively, but I'd think there would be some sort of compatibility mode.  Has
> anyone had success with this using the intel 875 and 865 series chipsets?
> Are there any other issues with that chipset and FreeBSD 4.x that I should
> be aware of?
>
> Note: I'm only interested in booting the system - if that means the drives
> have to run in polling mode, or ATA-33 or without ultra-DMA, so be it - I
> just want to know if that config CAN work.
>
> I read on the linux mailing lists that this exact config DOES work on linux
> 2.4 kernels, in some sort of compatibility mode.  Will this be usable on
> FreeBSD as well?
>>>

The "some sort of compatibility" mode is called "legacy" mode.  You set it
in the main BIOS.  In this mode, the 875/865 series chipsets (actually the
ICH5 chip) make the SATA disks appear to be on one of the channels of the
traditional motherboard ATA controller and they probably work fine in this
mode with almost any OS that understands traditional motherboard ATA.
There may be some confusion over the ATA cable type, but as long as the
driver configures the drives for some sort of DMA, they will do SATA150.

The Intel 875/865 (ICH5) SATA controller works in native (non-legacy)
mode beginning with FreeBSD 4.9 and 5.x.  The 4.9 driver does not
understand much about SATA but it seems to work quite well enough.
This controller also seemed to work correctly in native mode under 5.1.
The 5.x driver is in flux at the moment.  It seems to have lots of
difficulty with this particular SATA controller.  I don't know how
seriously the bugs are viewed by the FreeBSD release engineering team
(or if the bugs will be fixed in 5.2).

Note that the HARDWARE.TXT files in FreeBSD releases still do not claim
any particular support for Intel 875/865 (ICH5) ATA controllers.
I don't know if this is policy or an oversight.

Dan Strick
strick at covad.net