Date: Sat, 04 Apr 2015 01:47:33 -0700 From: Rui Paulo <rpaulo@me.com> To: Bruce Evans <brde@optusnet.com.au> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org, Rui Paulo <rpaulo@freebsd.org> Subject: Re: svn commit: r281059 - head/sys/boot/efi/boot1 Message-ID: <6AF43C66-5436-4F8F-BDEC-B7C75A4D58DA@me.com> In-Reply-To: <20150404175620.V1951@besplex.bde.org> References: <201504040427.t344RtGZ095522@svn.freebsd.org> <20150404175620.V1951@besplex.bde.org>
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On Apr 4, 2015, at 00:27, Bruce Evans <brde@optusnet.com.au> wrote: >=20 > On Sat, 4 Apr 2015, Rui Paulo wrote: >=20 >> Log: >> boot1 EFI: reset the screen and select the best mode. >>=20 >> It's necessary to reset the screen to make sure any vendor pixels are >> gone when we start boot1. In the Lenovo X1 (3rd gen), this is the >> only way to clear the screen. Previously, the Lenovo logo would only >> disappear after the kernel started scrolling the display. >>=20 >> After resetting the screen, EFI could put us in the worst LCD mode >> (oversized characters), so we now find the largest mode we can use = and >> hope it's the most appropriate one (it's not trivial to tell what's >> the correct LCD resolution at this point). It's worth noting that = the >> final stage loader has a 'mode' command that can be used to switch >> text modes. >=20 > :-(. >=20 > I just complained about the bug that vt (on non-EFI) clears the screen > where sc carefully preserves the screen in its history buffer. In my case, the "buffer" was a Lenovo logo. In other cases it might = include POST messages, but like you said vt already clears it. > For graphics mode, determining the resolution is the trivial part :-). > You also need OCR or something to translate the pixels into the format > of your history buffer. Don't forget to fetch Lenevo's history buffer > and translate it into your format :-). >=20 > I don't have problems with boot logos except when the battery dies, > since I turn them off until the CMOS forgets, but lose boot messages > in another way from newer monitors blanking the screen after mode > switches for much longer than older monitors. I expected newer = systems > to "fix" this by using the same graphics mode for the whole boot. This is very specific to EFI. FreeBSD has always strived to give you = text messages during boot and, while it would be easy to have the = FreeBSD logo all the way to Xorg like Ubuntu does, I don't see that = happening any time soon. Speaking of mode switching, they are pretty fast on this system. > Resetting the screen is even worse than clearing. Whole boots should > take a second or 2. I don't get close to that. More like 20. But = with > the monitor blanking the screen for 5+ seconds afer every mode switch, > even a 20-second boot gives almost no time for reading its messages. > Saving the messages in history buffers or booting with -p becomes more > important. In my system, these EFI calls (reset + clear) don't take long. I can't = tell any difference between the old boot time and the new boot time. -- Rui Paulo
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