From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Graf Date: Thu, 12 Oct 2017 09:15:04 +0200 Subject: [U-Boot] [PATCH 06/11] efi_loader: Decouple EFI input/output from stdin/stdout In-Reply-To: References: <20171010122309.25313-1-robdclark@gmail.com> <20171010122309.25313-7-robdclark@gmail.com> <1b1e837f-8d71-fddf-3492-3f163a7163b7@suse.de> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 12.10.17 00:07, Rob Clark wrote: > On Wed, Oct 11, 2017 at 10:45 AM, Alexander Graf wrote: >> >> >> On 10.10.17 14:23, Rob Clark wrote: >>> In some cases, it is quite useful to have (for example) EFI on screen >>> but u-boot on serial port. >>> >>> This adds two new optional environment variables, "efiin" and "efiout", >>> which can be used to set EFI console input/output independently of >>> u-boot's input/output. If unset, EFI console will default to stdin/ >>> stdout as before. >>> >>> Signed-off-by: Rob Clark >> >> With this patch, we lose the ability to have the efi in/out go to both >> graphical and serial console, right? This is critical functionality to >> have, since we don't necessarily know which output/input a user ends up >> using. > > I'll think about how to support iomux.. but some things like console > size are just not going to work properly there. And as long as we fix Yeah, those probably would need to get special cased. > the stdout shenanigans (ie. what I was seeing w/ qemu-x86) you can > simply not set efiout var and have things working as before, so you > don't loose any existing functionality (although, like I said, if the > two different consoles have different sizes things aren't going to > work properly for anything other than simple cases). > > In most cases, the display driver should be able to detect whether a > display is connected.. this is what I've done on dragonboard410c, so > if no display plugged in, 'efiout=vidconsole' fails and you fall back > to serial, else you get efi on screen like you would on a "real" > computer. For boards that have a display driver that isn't able to do > the basic check of whether a cable is plugged in, just don't set > "efiout" (or fix the display driver) ;-) Are you sure that's what happens on a "real" computer? As far as I remember from all ARM servers running edk2 based firmware that I've touched so far, the default is always to display on serial *and* graphical output at the same time. Alex