Date: Fri, 10 Feb 2012 09:45:48 -0700 From: Warner Losh <imp@bsdimp.com> To: Brooks Davis <brooks@FreeBSD.org> Cc: Aleksandr Rybalko <ray@ddteam.net>, freebsd-arch@FreeBSD.org Subject: Re: dynamic attach of hinted devices Message-ID: <4996D1CF-25E5-4422-996C-DF23B5C10732@bsdimp.com> In-Reply-To: <20120210110243.GA2012@lor.one-eyed-alien.net> References: <20120131213857.86c81626.ray@ddteam.net> <20120210110243.GA2012@lor.one-eyed-alien.net>
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On Feb 10, 2012, at 4:02 AM, Brooks Davis wrote: > On Tue, Jan 31, 2012 at 09:38:57PM +0200, Aleksandr Rybalko wrote: >> Hi FreeBSD hackers, >>=20 >> at first I want to say this: :) >> WARNING: FOLLOWING DEVCTL PATCH MAY EASILY PANIC YOUR SYSTEM, PLEASE >> DO NOT TRY IT ON PRODUCTION SERVERS AND TRY IT WITH FILESYSTEMS = MOUNTED >> AS READONLY :))))) >>=20 >> So I introduce two patches first one [1] used to migrate from >> static_hints or hints in the static_kenv to dynamic hints. >>=20 >> sysctl kern.hintmode=3D2 will copy hints from static hints or from = static >> kenv and put it into dynamic kenv. Those will allow to manipulate = hints >> values and attach hinted devices with devctl tool. >>=20 >> Second [2] allow attach/detach devices with userland tool devctl. >>=20 >> devctl tool allow add and initialize new devices which is not able to >> be autoenumerating, such a hinted devices. >>=20 >> Both designed to have ability update EEPROM items in runtime, since >> some device can't work in mode when it accessible like a EEPROM chip. >>=20 >> Example: >> # sysctl kern.hintmode=3D2 >> # kenv hint.mx25l.0.at=3D"spibus0" >> # kenv hint.mx25l.0.cs=3D0 >> # kenv hint.mx25l.0.chipname=3D"at25128" >> # devctl hinted spibus 0 mx25l 0 >> mx25l0: <M25Pxx Flash Family> at cs 0 mode 0 on spibus0 >> mx25l0: at25128, sector 64 bytes, 256 sectors >> GEOM: new disk flash/spi0 >>=20 >> Someone may found it also useful for testing device attach/detach = code >> (memory leaks, resource allocation, etc). >>=20 >> So, say me please your opinion. >=20 > I skimmed over the patch and the concept looks good to me. I'm = probably > not the right person to review this proposal in detail, but perhaps = John > Baldwin (cc'd) could do it or suggest someone. I've looked at it and it looks OK, but I had lots of feedback I didn't = have time to write up. I like the concept, but have lots of suggestions = for improvement since I'd like to see this more generically done. Warner=
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