On Sun, May 29, 2005 at 07:23:52PM +0200, Erik Slagter wrote:
> On Sun, 2005-05-29 at 12:59 -0400, Jeff Garzik wrote:
> > > My question was if there is a fundamental reason why the AHCI mode of
> > > the ICH6/7 must be enabled by the BIOS, is there a reason why the kernel
> > > doesn't do it, or can't do it?
> >
> > The BIOS sets up PCI resources necessary to use AHCI mode.
>
> Ok. So there's absolutely no way to do that afterwards? It'd really be a
> pity :-(
It is technically possible. BIOS is just software, just like the OS.
It's just a huge pain in the butt, because the kernel might accidentally
stomp on some resources the BIOS secretly set up, or somesuch.
> On the same subject: is there a reason why ICH6 gets "BAR0-3 ignored"
> and always gets the legacy i/o ports and IRQ's assigned? I'd say there
> is absolutely no need to be compatible in this way, the PCI code can
> assign the IRQ and I/O ports as with any other PCI device?
IDE is special.
This is due to how the BIOS sets up an IDE PCI device in legacy mode.
BAR0-3 are set to zero, which is a signal to the OS that the IDE PCI
device is in legacy mode (io 0x1f0+0x170, irq 14+15). Since the IDE I/O
ports are in ISA space not PCI space, the PCI BARs reflect nothing.
Jeff
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
