Date: Sat, 9 May 1998 15:21:37 +0200 From: Stefan Esser <se@FreeBSD.ORG> To: Stefan Bethke <stefan@promo.de> Cc: FreeBSD Hackers <freebsd-hackers@FreeBSD.ORG>, Stefan Esser <se@FreeBSD.ORG> Subject: Re: ISA PnP / snd PnP developments? Message-ID: <19980509152137.30068@mi.uni-koeln.de> In-Reply-To: <326400.3103442037@d254.promo.de>; from Stefan Bethke on Wed, May 06, 1998 at 11:13:57AM %2B0200 References: <326400.3103442037@d254.promo.de>
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On 1998-05-06 11:13 +0200, Stefan Bethke <stefan@promo.de> wrote: > --On Die, 5. Mai 1998 23:47 Uhr +0200 "Stefan Esser" <se@freebsd.org> wrote: > > > > On 1998-05-05 11:37 +0200, Stefan Bethke <stefan@promo.de> wrote: > >> Btw., you might want to adjust the comments in sys/i386/isa/pcibus.c, > they > >> might prove to be somewhat misleading. > > > > Hmmm, what's wrong with the comments in that file ? > > Under which version of FreeBSD, BTW ? > > 1.27.2.1 (RELENG_2_2_6_RELEASE, RELENG_2_2) says: > .. > /*----------------------------------------------------------------- > ** > ** The following functions are provided by the pci bios. > ** They are used only by the pci configuration. > ** > ** pcibus_setup(): > .. > > And from what I currently can see in that file, it doesn't do any BIOS > calls. I see ... Well, the comment is a little misleading, but not wrong, nonetheless ... :) In fact, the functions listed in that comment are really primitives provided by the PCI BIOS. The PCI code in 2.2 originates from a time, when the PCI BIOS could not be trusted, and since the PCI BIOS is a PC only thing (not defined for processors other than Intel x86, anyway), we just implemented those functions based on register accesses instead of BIOS calls. The PCI BIOS uses terrible parameter passing conventions, and although we have BIOS32 support in the kernel, I did not rewrite the low-level PCI code to take advantage of the BIOS, yet. Only two primitives should rely on the BIOS, anyway, IMHO: Testing for the PCI configuration mechanism to use, and the function that returns the highest PCI bus number that has to be probed. Regards, STefan To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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