Date: Wed, 11 Mar 1998 16:22:28 +0100 From: Eivind Eklund <eivind@yes.no> To: "Justin T. Gibbs" <gibbs@narnia.plutotech.com> Cc: hackers@FreeBSD.ORG Subject: Re: userconfig data -> linker set -> ELF segment Message-ID: <19980311162228.43166@follo.net> In-Reply-To: <199803111444.HAA10346@narnia.plutotech.com>; from Justin T. Gibbs on Wed, Mar 11, 1998 at 07:44:27AM -0700 References: <199803111011.CAA22528@dingo.cdrom.com> <199803111444.HAA10346@narnia.plutotech.com>
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On Wed, Mar 11, 1998 at 07:44:27AM -0700, Justin T. Gibbs wrote: > In article <199803111011.CAA22528@dingo.cdrom.com> you wrote: > >> > I was basically planning to look at distributing the userconfig device > >> > list as a linker set, to allow externally developed drivers to be > >> > added without having to edit a static list. I know how to do this > >> > now, but how easy is it to put it in a non-loaded segment later? > >> > >> This is hard. > >> > >> The problem is that you need to be able to agregate linker sets > >> at run time, not at link time. > > > > You're making things too difficult. 8) > > Exactly. Don't use a linker set at all. Convert all drivers to > LKMs, load they "probe" section of all LKMs, have an entry point > in the probe section register the driver with userconfig. This is not feasible at present. There are several reasons: * The PCI LKM code in -current doesn't work * Loading 'just the probe code' isn't possible using a.out (AFAIK) * Depending on device drivers being LKMs lowers reliability (N files that can fail, instead of just having a single kernel) * The probe is too late - userconfig (presently, at least) run before anything is probed - to be able to stop harmful probes etc. * It is more work than I can chew, and thus won't be done as part of the minor set of changes I wanted to do. I was only planning to make userconfig data a linker set, and change config to (also) scan sys/conf/*/files.extra and sys/conf/*/options.extra, as an enabling technology for externally developed kernel parts. > Linker sets are a pain. Why more so than LKMs? As far as I can tell, LKMs are presently more of a pain than linker sets (though LKMs is also a more powerful enabling technology). Eivind. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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