FreeBSD 7.0 SATA Controller

[Jeremy Chadwick]

On Sat, May 03, 2008 at 09:15:24PM -0400, Shaun Sabo wrote:
> so does that mean i need to disable the apic? and are we talking about apic
> now or acpi? im getting all these devices confused now. i realize that acpi
> is dissabled when you press number 2 at the boot menu but are we talking
> about that or apic?

ACPI:	Commonly used for system configuration data (stored/controlled by
	BIOS), power management, and a couple other things.  Unrelated
	to APIC and ATPIC.
APIC:	Advanced interrupt routing IC; more or less used to extend
	interrupt limitations of old PIC-based interrupts.  Originally
	there were 16 IRQs, most taken up by system necessities.  An APIC
	extends that to 256 IRQs, providing each device with its own IRQ,
	assuming the OS supports APICs, otherwise it'll resort to
	classic 16 IRQ behaviour (sharing of IRQs, etc.)
	http://en.wikipedia.org/wiki/Advanced_Programmable_Interrupt_Controller
ATPIC:	Classic 8259 PIC ("AT PIC"), 16 IRQ limitation, etc.
	http://en.wikipedia.org/wiki/8259

Hope this clears things up for you.

I've never seen a system made in the past 7-8 years which demands the
use of atpic.  Most present-day systems, even uni-processor systems,
have an APIC, and most of the time those work without issue.

If you want to disable the APIC, you can do so by booting FreeBSD
in "safe mode".  It should be a menu item; I forget which number.

"Safe mode" will disable the following things:

* Disable use of ACPI
* Disable APIC
* Disable DMA capability on ATA devices (does not apply to SATA)
* Disable DMA capability on ATAPI device (CD/DVD-ROMs, etc.)
* Disabled hard disk write caching
* Disables kbdmux(4)
* Does something with hw.eisa_slots, which I don't quite understand.
  Only "easy" reference I can find is to old Adaptec controllers
  requiring hw.eisa_slots="12".

-- 
| Jeremy Chadwick                                jdc at parodius.com |
| Parodius Networking                       http://www.parodius.com/ |
| UNIX Systems Administrator                  Mountain View, CA, USA |
| Making life hard for others since 1977.              PGP: 4BD6C0CB |