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From: Andy Shevchenko <andy.shevchenko@gmail.com>
Date: Tue, 4 Apr 2017 21:04:24 +0300
Message-ID: <CAHp75VfQVdMRZnbDFyH9m=HfSuoiUxqhf2y+H07u4u6xPd7DUA@mail.gmail.com>
Subject: Re: [PATCH v2 0/5] minitty: a minimal TTY layer alternative for
 embedded systems
To: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>,
        Stuart Longland <stuartl@longlandclan.id.au>,
        Nicolas Pitre <nicolas.pitre@linaro.org>,
        Andi Kleen <andi@firstfloor.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jiri Slaby <jslaby@suse.com>,
        "linux-serial@vger.kernel.org" <linux-serial@vger.kernel.org>,
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On Tue, Apr 4, 2017 at 8:59 PM, Tom Zanussi <tom.zanussi@linux.intel.com> wrote:
> On Tue, 2017-04-04 at 20:08 +0300, Andy Shevchenko wrote:
>> On Tue, Apr 4, 2017 at 7:59 PM, Tom Zanussi <tom.zanussi@linux.intel.com> wrote:
>> > On Tue, 2017-04-04 at 00:05 +0300, Andy Shevchenko wrote:

>> > I was focused at that point mainly on the kernel static size, and using
>> > a combination of Josh Triplett's tinification tree, Andi Kleen's LTO and
>> > net-diet patches, and my own miscellaneous patches that I was planning
>> > on eventually upstreaming, I ended up with a system that I could boot to
>> > shell with a 455k text size:
>> >
>> > Memory: 235636K/245176K available (455K kernel code, 61K rwdata,
>> > 64K rodata, 132K init, 56K bss, 3056K reserved, 0K cma-reserved)

>> Thanks for sharing your experience. The question closer to this
>> discussion what did you do against TTY/UART/(related) layer(s)?
>>
>
> I'd have to go back and take a look, but nothing special AFIAR.
>
> No patches or hacks along those lines, and the only related thing I see
> as far as config is:
>
>         cfg/pty-disable.scc \
>
> which maps to:
>
>         # CONFIG_UNIX98_PTYS is not set

But on your guestimation how much can we squeeze TTY/UART layer if we
do some compile-time configuration?
Does it even make sense or better to introduce something like minitty
special layer instead?

I believe you did some research during time of that project…

-- 
With Best Regards,
Andy Shevchenko