Date: Sun, 21 Mar 2004 11:51:56 +0200 From: Valentin Nechayev <netch@ivb.nn.kiev.ua> To: Marcel Moolenaar <marcel@xcllnt.net> Cc: "M. Warner Losh" <imp@bsdimp.com> Subject: Re: cvs commit: src/sys/conf files src/sys/dev/uart uart_cpu.h uart_cpu_alpha.c uart_cpu_amd64.c uart_cpu_i386.c uart_cpu_ia64.c uart_cpu_pc98.c uart_cpu_sparc64.c uart_subr.c Message-ID: <20040321095156.GA4401@iv.nn.kiev.ua> In-Reply-To: <20040320200437.GB84959@dhcp01.pn.xcllnt.net> References: <200403200214.i2K2E3ps052217@repoman.freebsd.org> <20040320080027.GC567@funkthat.com> <20040320085431.GA74398@dhcp01.pn.xcllnt.net> <20040320.104521.08405415.imp@bsdimp.com> <20040320200437.GB84959@dhcp01.pn.xcllnt.net>
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Sat, Mar 20, 2004 at 12:04:37, marcel (Marcel Moolenaar) wrote: >> Only for devices that have fixed addresses. This wouldn't be true for >> devices on the PCI bus, where probe order could affect the resources >> assigned to a given device. The only real way for self-enumearting >> busses are a bus-specific address. MM> Devices that don't have a fixed address cannot be used as low-level MM> console as there's no way we can know where the device is. Fixed address does not obligate to be fixed port address. E.g., PCI bus address can uniquely identify extension card and single device on it. For ethernet cards, MAC address is unique identifier, so identification is based on feature, not port address or even bus address. It is useful even for low-level console: there is no unavoidable limitation not to reconfigure console (or even add additional consoles). Thus happened that hints are used not only as attaching address helpers, but also as enumeration helpers. It is highly important task for many situations to wire down enumeration. Old config style with 'device xx1 at yy0 target 3...' does this. If one say hints can't satisfy this task (there was such voices in this thread), I treat them as useless and highly confusing mechanism. -netch-
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