Date: Sat, 20 Mar 2004 13:44:02 -0800 From: Marcel Moolenaar <marcel@xcllnt.net> To: John-Mark Gurney <gurney_j@efn.org> Cc: cvs-all@FreeBSD.org 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: <20040320214402.GA91919@dhcp01.pn.xcllnt.net> In-Reply-To: <20040320205356.GE567@funkthat.com> References: <200403200214.i2K2E3ps052217@repoman.freebsd.org> <20040320080027.GC567@funkthat.com> <20040320085431.GA74398@dhcp01.pn.xcllnt.net> <20040320185640.GD567@funkthat.com> <20040320201610.GC84959@dhcp01.pn.xcllnt.net> <20040320205356.GE567@funkthat.com>
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On Sat, Mar 20, 2004 at 12:53:56PM -0800, John-Mark Gurney wrote: > Marcel Moolenaar wrote this message on Sat, Mar 20, 2004 at 12:16 -0800: > > > > Probe order is irrelevant if you specify the device by its I/O port > > > > or memory mapped I/O address. When you need to pinpoint a device > > > > prior to any form of bus enumeration, the unit number is meaningless > > > > and any mechanism that includes a unit number is bogus. That's why > > > > hints are the wrong tool for pinpointing a console or debug port. > > > > > > I hope that you don't have to specify the console via io/memory port.. > > > > Yes you have. This is no different than hints, except that you set > > flags in that case to tell uart(4) that the device is to be used as > > a console or debug port. But you still need to specify the I/O port > > because without it your hint is bogus. > > My objection is to Yet Another Hint Place to stick IO/Memory wiring down > addresses... You're missing the point. The hw.uart.console and hw.uart.dbgport variables do not wire down anything. They simply tell uart(4) that the serial device at that particular address is to be used as a console or debug port. We're not programming any chipsets to put a serial device at that address, nor do we reserve that address in some form or another and automagically have a serial device show up during bus enumeration. Hence, they are not hints and they do not depend on hints. Hints are a thing of the past and useful only on certain platforms. One should not gratuitously and artificially add a dependency to hints. Yes, this also means SCSI busses... -- Marcel Moolenaar USPA: A-39004 marcel@xcllnt.net
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