From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jamie Lokier Subject: Re: [PATCH] console - Add configurable support for console charset translation Date: Mon, 9 Jun 2008 12:38:56 +0100 Message-ID: <20080609113856.GD25541@shareable.org> References: <48447615.5050806@am.sony.com> <200806041236.12349.rob@landley.net> <20080605004630.GA26259@linux-sh.org> <200806051835.57140.rob@landley.net> <484A0207.4000405@zytor.com> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <484A0207.4000405@zytor.com> Sender: linux-embedded-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: "H. Peter Anvin" Cc: Rob Landley , Paul Mundt , linux-embedded H. Peter Anvin wrote: > >When you imply it's stupid to think anyone will ever have a console on an > >embedded system (because we all know the embedded world is far more > >uniform than crazy diverse things like the desktop space), which of these > >are _you_ referring to? > > I'm talking about the virtual console stuff, which is *not* inherently > tied to VGA. > > The issue is whether it makes sense to have virtual console capability > on a device which is so constrained that you want a *subset* of the > functionality in place. The uClinux devices I ship do have that. System console is the serial port on a board header. But field engineers are instructed to plug in a USB keyboard and Alt-F2 to get a diagnostic screen (we call it a "shell" ;-). Occasionally even customers with specific requirements get to use that. We had to patch the kernel to get the combination of virtual terminal capability on a framebuffer, but system console messages not to the framebuffer. The uClinux (2.4.x) disables system console on a virtual terminal, but due to some confusion(*), it has the side effect that you can't attach a VT to a framebuffer at all. Several howtos provide a "con2fb" program which didn't work with uClinux. We had to fix that. (*) - the word "console" is used for four different concepts in the kernel, sometimes in the same code, and it seems to have confused someone.(**) In the following, CONFIG_VT_CONSOLE should not control take_over_console(); the two "console" are not the same concept: #ifdef CONFIG_VT_CONSOLE take_over_console(&fb_con, first_fb_vc, last_fb_vc, fbcon_is_default); #endif (**) So I suggest using "virtual terminal" consistently in the code, and when talking about them, would be an improvement. -- Jamie