[U-Boot] [PATCH v4 0/3] arm: tegra: apalis-tk1 and ext clock loopback

[Marcel Ziswiler <marcel.ziswiler@toradex.com>]

Hi Alexander

On Tue, 2017-03-21 at 14:50 +0100, Alexander Graf wrote:
> 
> On 21/03/2017 14:37, Marcel Ziswiler wrote:
> > Hi Alex
> > 
> > On Tue, 2017-03-21 at 10:46 +0100, Alexander Graf wrote:
> > > 
> > > On 21/03/2017 10:29, Marcel Ziswiler wrote:
> > > > This series adds support for the Toradex Apalis TK1 and
> > > > introduces
> > > > a new
> > > > option to disable the external clock loopback on SDMMC3.
> > > > 
> > > > The whole series is also available here:
> > > > 
> > > > http://git.toradex.com/cgit/u-boot-toradex.git/log/?h=for-next
> > > > 
> > > > Changes in v4:
> > > > - Re-based.
> > > > - Drop patches 2 and 3:
> > > >     mmc: tegra: move CONFIG_TEGRA_MMC from headers to
> > > > defconfigs
> > > >     mmc: tegra: introduce CONFIG_TEGRA_MMC to Kconfig
> > > >   in favor of commit 1d2c0506d31a9997e5ffc22e90942902f673b107
> > > >     mmc: move more driver config options to Kconfig
> > > >   from Masahiro.
> > > > - Meld patch 6
> > > >     apalis-tk1: clean-up defconfig
> > > >   into first one.
> > > > - Add distro boot fallback.
> > > > - Enable FIT and device tree overlay support.
> > > > - Explicitly drop EFI loader support.
> > > 
> > > Any particular reason for this?
> > 
> > Yes, a waste of 20K which on some of our modules is rather crucial.
> > I
> > personally think force enabling EFI for everything was not too
> > smart an
> > idea but whatever.
> 
> Well, it's enabled by default for a good reason: Compatibility.

While I do agree about compatibility I don't quite see what this has to
do with EFI. I personally don't believe the BIOS/EFI disaster of the
x86 world is worth copying to ARM, sorry. Other distributions like
Fedora e.g. achieve the same with distro boot isn't it? After all isn't
the device tree the agreed upon hardware description in the ARM world?

> I want to move to a world where people can just take a random
> distribution and expect it to work, rather than waste weeks over
> weeks on fiddling around with random BSPs that nobody really wants
> only to realize 2 years down the road that their security footprint
> is en par with a swiss cheese.

Hey, nothing against Swiss cheese! And BTW the term Swiss cheese is
about as nonsense as the term Linux. There is really a huge collection
of different Swiss cheeses... Sorry, I just do get upset at times if
certain countries gastronomy people do ask whether I want my sandwich
with Swiss cheese wondering what they mean by that. But I guess those
chaps now do have their very own issues (;-p).

> It's also the preferred option to boot BSD for example.
> 
> So how bad are the 20k for you? In fact, I'm surprised it's 20k at
> all - 
> it used to be 10k. The overhead of DM should be much higher and I
> doubt 
> you want to disable that ;). Usually a full U-Boot build is ~500k,
> so 
> even at 20k we're talking about 4% - less than a compiler update
> usually 
> gets you.
> 
> If size really is such a big concern, moving to THUMB code is going
> to 
> buy you much more in storage savings than dropping (quite useful)
> UEFI 
> support.
> 
> If however there are real technical issues with it, I'm happy to
> hear 
> them and fix them as far as possible.

The technical issue is that I still don't quite see why U-Boot needs
EFI. I stopped using SuSE more than 15 years ago and never regretted
it, no pun intended.

But if it is really agreed upon mandatory to enable it I am happy to do
so as I would love to finally get that thing in after an almost 4
months endeavour.

> Alex

Cheers

Marcel