linux-kernel - Re: Serial consoles (was: [Ksummit-2013-discuss] [HOBBYIST ATTEND] IIO maintainer and developer)

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:	Thu, 10 Oct 2013 08:50:37 +0200
From:	Pavel Machek <pavel@....cz>
To:	Geert Uytterhoeven <geert@...ux-m68k.org>
Cc:	Linus Walleij <linus.walleij@...aro.org>,
	Rob Landley <rob@...dley.net>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	ksummit-2013-discuss@...ts.linuxfoundation.org
Subject: Re: Serial consoles (was: [Ksummit-2013-discuss] [HOBBYIST ATTEND]
 IIO maintainer and developer)


On Thu 2013-09-19 09:15:13, Geert Uytterhoeven wrote:
> > On Thu, Sep 12, 2013 at 10:12 PM, Rob Landley <rob at landley.net> wrote:
> > > 3) QEMU command line to boot to a shell prompt with serial console. x86 is
> > > ttyS0, arm versatile is ttyAMA0, sh4 is ttySC1. Get it wrong and you have no
> > > output.
> >
> > Can't we long-term fix this? Can we bring up both say ttyS0 and ttyAMA0
> > on a machine and remove the other one when the first is opened,
> > then print a friendly reminder to move over to ttyS0 if ttyAMA0 is
> > used instead, so people are encouraged to switch to ttyS0
> > for everything over time?
> >
> > Or do these separate serialport namespaces have a real utility?
> 
> I'd say they make life more difficult.
> Making it easier to distinguish ports may have been the original reason, but
> in other subsystems ("SCSI" disks, Ethernet ports, IDE, ...) there is a uniform
> device namespace.
> We still have different namepaces for other types of block devices, though, but
> that's (usually) handled automatically by udev, file system UUIDs, etc.
> 
> Note that on m68k we never followed the non-16550-ports-should-use-a-different-
> name-franze, and always continued using /dev/ttyS* for all serial ports.

Well.. spitz (ARM) does the same -- registers ttyS0 for its serial ports. But then
I plugged bluetooth CF card... with 16550 port... and things got "interesting".

I don't think it was ever solved, as serial layer does not support uniform device
namespace...

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/