[U-Boot-Users] Warning for mpc8360emds users: fdt-cmd from u-boot-fdt.git

Bruce_Leonard at selinc.com
2007-04-05T18:02:17Z

Hi all

u-boot-users-bounces at lists.sourceforge.net wrote on 04/05/2007 04:00:15
AM:

> Wolfgang Denk wrote:
> > In message <46146842.8060509@gmail.com> you wrote:
> >> If bootm edits/augments the FDT, the boot scripts/user has no chance
to
> >> change the items it edits/augments (biggie: the chosen node), or even

> >> print it before linux is launched. This defeats 90% of the purpose
of
> >> the fdt command - allowing the user/script customize the blob before
> >> linux is launched.
> >
> > I agree that it should be *possible* to do this, if wanted.Similar
> > like we can set up our own contents of thebootargs variable.
> >
> > On the other hand, bootm should do everything that is necessary to
> > start a kernel without such interaction, if needed.
> >
<snip snip>

My two cents worth (for what it's worth :-/): from the standpoint of
someone using uboot for the first time and having to learn from the ground
up without the benefit of having used this stuff for many years, I agree
with Wolfgang. It took me two weeks just to figure out what a device tree
is and that I even needed one. It took me two more days to figure out how
to create the blob and how to use it. I still don't know the details of
DTS files, what needs to be in them or what the different fields mean.
Adding another step/level of obscurity with REQUIRING the use of fdt
commands and/or scripts is just another barrier to new users. And I have
to tell you, this thing is a bear to learn. For folks who have been
digging around in the guts of it, I'm sure it's trivial. But I at least
am pretty overwhelmed by it.

I think it would be great to have the option of using the ftd commands if
it suited your purpose, but still be able to use things as they currently
are. That would be the most flexible, give the expert users something
they want, and not add yet another thing that new people HAVE to learn
just to get an OS to boot.

Again just my 2 cents. Flames welcome.

Bruce