Serial console of 12.0-ALPHA3 fiddles with the terminal colors

[Kyle Evans]

On Mon, Aug 27, 2018 at 7:34 PM Dr. Rolf Jansen <rj at obsigna.com> wrote:
>
> > Am 27.08.2018 um 20:22 schrieb Kyle Evans <kevans at freebsd.org>:
> >
> > On Mon, Aug 27, 2018 at 6:09 PM Dr. Rolf Jansen <rj at obsigna.com> wrote:
> >>
> >> Hello,
> >>
> >> I updated my BeagleBone Black to 12.0-ALPHA3, and now, when booting, the serial console behaves differently (I use cu from a Mac Terminal via a FDTI/USB adapter).
> >>
> >> When it comes to "Loading kernel...", the terminal color is inverted, instead of maintaining the usual black on white, all over the sudden everything is displayed in white on black. And more seriously, the logging before loading the kernel, is deleted, which means I cannot see the diagnostics of the u-boot loader.
> >>
> >> Is there any setting, to prevent the serial console manipulates color and content of a terminal session?
> >>
> >
> > Hi,
> >
> > You want loader_color in your loader.conf(5), which should (hopefully)
> > disable all color while still being usable. We force the color scheme
> > to white on black if colors are displayed because we can't necessarily
> > sample or Q/A our color choice on all possible configurations.
> >
> > I'll double check on the screen clearing... I don't recall adding any
> > extra clears except for password prompts and (re-)drawing the menu.
> >
> > Thanks,
> >
> > Kyle Evans
>
> Thank you for the quick reply.
>
> I added loader_color="NO" and this didn't change anything. The u-boot loader diagnostics is shown in black on white, then the FreeBSD boot loader takes over, and the first thing, which it does is deleting the u-boot loader diagnostics and then it switches the background to black and the following is all white on black.

Hmm... I'll take a look at this shortly. If colors are disabled, I
think we should be leaving colors alone (full stop), to include the
background reset. This must be a bug that I introduced. =(

> What again is the purpose of setting the color scheme in the serial console? I understand that something shall be set on the real screen, now in a terminal window? Think about the poor people who like it green on pink, and you change it to white on black, come on :-)

I blame imp at . =) In reality, though, I don't think we had a good
reason for not allowing it by default and moving to a world where we
just respect loader_color simplified quite a bit that was originally
written to check if we're writing to a serial console.

> Bets regards
>
> Rolf